Signal chain++

This reverts commit 79dab822fd.

.gitmodules

@@ -1,22 +1,9 @@
+[submodule "External/ReactiveCocoa"]
+	path = External/ReactiveCocoa
+	url = https://github.com/ReactiveCocoa/ReactiveCocoa.git
+[submodule "External/Mantle"]
+	path = External/Mantle
+	url = https://github.com/github/Mantle.git
 [submodule "External/OHHTTPStubs"]
 	path = External/OHHTTPStubs
 	url = https://github.com/github/OHHTTPStubs
-[submodule "Carthage.checkout/Nimble"]
-	path = Carthage/Checkouts/Nimble
-	url = https://github.com/Quick/Nimble.git
-[submodule "Carthage.checkout/ReactiveCocoa"]
-	path = Carthage/Checkouts/ReactiveCocoa
-	url = https://github.com/ReactiveCocoa/ReactiveCocoa.git
-[submodule "Carthage.checkout/Quick"]
-	path = Carthage/Checkouts/Quick
-	url = https://github.com/Quick/Quick.git
-[submodule "Carthage.checkout/xcconfigs"]
-	path = Carthage/Checkouts/xcconfigs
-	url = https://github.com/jspahrsummers/xcconfigs.git
-[submodule "Carthage.checkout/Mantle"]
-	path = Carthage/Checkouts/Mantle
-	url = https://github.com/Mantle/Mantle.git
-[submodule "Carthage/Checkouts/Nimble"]
-	url = https://github.com/Quick/Nimble.git
-[submodule "Carthage/Checkouts/Quick"]
-	url = https://github.com/Quick/Quick.git

Cartfile

@@ -1,2 +0,0 @@
-github "Mantle/Mantle" ~> 1.5.3
-github "ReactiveCocoa/ReactiveCocoa" ~> 2.4.3

Cartfile.private

@@ -1,3 +0,0 @@
-github "jspahrsummers/xcconfigs" >= 0.7.1
-github "Quick/Quick" ~> 0.2
-github "Quick/Nimble" ~> 0.2

Cartfile.resolved

@@ -1,5 +0,0 @@
-github "Mantle/Mantle" "1.5.3"
-github "Quick/Nimble" "v0.2.0"
-github "Quick/Quick" "v0.2.2"
-github "ReactiveCocoa/ReactiveCocoa" "v2.4.3"
-github "jspahrsummers/xcconfigs" "0.7.1"

README.md

@@ -13,49 +13,23 @@ suitable update.
 
 The update JSON Squirrel requests should be dynamically generated based on
 criteria in the request, and whether an update is required. Squirrel relies
-on server side support for determining whether an update is required, see
-[Server Support](#server-support).
+on server side support for determining whether an update is required, see [Server
+Support](#server-support) below.
 
-Squirrel's installer is also designed to be fault tolerant, and ensure that any
+Squirrel’s installer is also designed to be fault tolerant, and ensure that any
 updates installed are valid.
 
 ![:shipit:](http://shipitsquirrel.github.io/images/ship%20it%20squirrel.png)
 
 # Adopting Squirrel
 
-1. Install xctool with `brew install xctool`
 1. Add the Squirrel repository as a git submodule
-1. Run `script/bootstrap` from within the submodule
-1. Add references to Squirrel.xcodeproj and its [dependencies](#dependencies) to
-   your project
+1. Add a reference to Squirrel.xcodeproj to your project
 1. Add Squirrel.framework as a target dependency
 1. Link Squirrel.framework and add it to a Copy Files build phase which copies
 it into your Frameworks directory
-1. Ensure your application includes the [dependencies](#dependencies). Squirrel
-does not embed them itself.
-
-If you’re developing Squirrel on its own, then use `Squirrel.xcworkspace`.
-
-# Dependencies
-
-Squirrel depends on [ReactiveCocoa](http://github.com/ReactiveCocoa/ReactiveCocoa)
-and [Mantle](https://github.com/Mantle/Mantle).
-
-If your application is already using ReactiveCocoa, ensure it is using the same
-version as Squirrel.
-
-Otherwise, add a target dependency and Copy Files build phase entry for the
-ReactiveCocoa.framework target included in Squirrel's repository, in
-External/ReactiveCocoa.
-
-Similarly, ensure your application includes Mantle, or copies in the Squirrel
-version.
-
-Finally, ensure your application's Runpath Search Paths (`LD_RUNPATH_SEARCH_PATHS`)
-includes the directory that Squirrel.framework, ReactiveCocoa.framework
-and Mantle.framework are copied into.
-
-# Configuration
+1. Ensure your Runpath Search Paths (`LD_RUNPATH_SEARCH_PATHS`) includes the
+Frameworks directory Squirrel.framework is copied into
 
 Once Squirrel is added to your project, you need to configure and start it.
 
@@ -63,16 +37,7 @@ Once Squirrel is added to your project, you need to configure and start it.
 #import <Squirrel/Squirrel.h>
 
 - (void)applicationDidFinishLaunching:(NSNotification *)notification {
-	NSURLComponents *components = [[NSURLComponents alloc] init];
-
-	components.scheme = @"http";
-	components.host = @"mycompany.com";
-	components.path = @"/myapp/latest";
-
-	NSString *bundleVersion = NSBundle.mainBundle.sqrl_bundleVersion;
-	components.query = [[NSString stringWithFormat:@"version=%@", bundleVersion] stringByAddingPercentEncodingWithAllowedCharacters:NSCharacterSet.URLQueryAllowedCharacterSet]
-
-	self.updater = [[SQRLUpdater alloc] initWithUpdateRequest:[NSURLRequest requestWithURL:components.URL]];
+	self.updater = [[SQRLUpdater alloc] initWithUpdateRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"https://mycompany.com/myapp/latest"]]];
 
 	// Check for updates every 4 hours.
 	[self.updater startAutomaticChecksWithInterval:60 * 60 * 4];
@@ -83,26 +48,7 @@ Squirrel will periodically request and automatically download any updates. When
 your application terminates, any downloaded update will be automatically
 installed.
 
-## Update Requests
-
-Squirrel is indifferent to the request the client application provides for
-update checking. `Accept: application/json` is added to the request headers
-because Squirrel is responsible for parsing the response.
-
-For the requirements imposed on the responses and the body format of an update
-response see [Server Support](#server-support).
-
-Your update request must *at least* include a version identifier so that the
-server can determine whether an update for this specific version is required. It
-may also include other identifying criteria such as operating system version or
-username, to allow the server to deliver as fine grained an update as you
-would like.
-
-How you include the version identifier or other criteria is specific to the
-server that you are requesting updates from. A common approach is to use query
-parameters, [Configuration](#configuration) shows an example of this.
-
-## Update Available Notifications
+## Update Notifications
 
 To know when an update is ready to be installed, you can subscribe to the
 `updates` signal on `SQRLUpdater`:
@@ -113,18 +59,12 @@ To know when an update is ready to be installed, you can subscribe to the
 }];
 ```
 
-## Installing Updates
+If you've been notified of an available update, and don't want to wait for it to
+be installed automatically, you can terminate the app to begin the installation
+process immediately.
 
-While downloaded updates are automatically installed when your application
-terminates, if don't want to wait you can manually terminate the app to begin
-the installation process immediately.
-
-Once an [update available notification](#update-available-notifications) has
-been received, you may want to present an interface informing the user about
-the update and offering the ability to install and relaunch.
-
-To explicitly install a downloaded update and automatically relaunch afterward,
-subscribe to the `relaunchToInstallUpdate` signal on `SQRLUpdater`:
+If you want to install a downloaded update and automatically relaunch afterward,
+`SQRLUpdater` can do that:
 
 ```objc
 [[self.updater relaunchToInstallUpdate] subscribeError:^(NSError *error) {
@@ -132,26 +72,10 @@ subscribe to the `relaunchToInstallUpdate` signal on `SQRLUpdater`:
 }];
 ```
 
-# Server Support
+# Update JSON Format
 
-Your server should determine whether an update is required based on the
-[Update Request](#update-requests) your client issues.
-
-If an update is required your server should respond with a status code of
-[200 OK](http://tools.ietf.org/html/rfc2616#section-10.2.1) and include the
-[update JSON](#update-json-format) in the body. Squirrel **will** download and
-install this update, even if the version of the update is the same as the
-currently running version. To save redundantly downloading the same version
-multiple times your server must not inform the client to update.
-
-If no update is required your server must respond with a status code of
-[204 No Content](http://tools.ietf.org/html/rfc2616#section-10.2.5). Squirrel
-will check for an update again at the interval you specify.
-
-## Update JSON Format
-
-When an update is available, Squirrel expects the following schema in response
-to the update request provided:
+Squirrel requests the URL you provide with `Accept: application/json` and
+expects the following schema in response:
 
 ```json
 {
@@ -169,10 +93,23 @@ installing ZIP updates. If future update formats are supported their MIME type
 will be added to the `Accept` header so that your server can return the
 appropriate format.
 
-"pub_date" if present must be formatted according to ISO 8601.
+"pub_date" if present must be formatted according to ISO 8601
+
+# Server Support
+
+If an update is required your server should respond with a status code of
+[200 OK](http://tools.ietf.org/html/rfc2616#section-10.2.1) and include the
+update JSON in the body. Squirrel **will** download and install this update,
+even if the version of the update is the same as the currently running version.
+To save redundantly downloading the same version multiple times your server must
+inform the client not to update.
+
+If no update is required your server must respond with a status code of
+[204 No Content](http://tools.ietf.org/html/rfc2616#section-10.2.5). Squirrel
+will check for an update again at the interval you specify.
 
 # User Interface
 
 Squirrel does not provide any GUI components for presenting updates. If you want
 to indicate updates to the user, make sure to [listen for downloaded
-updates](#update-available-notifications).
+updates](#update-notifications).

Squirrel.xcodeproj/xcshareddata/xcschemes/Squirrel.xcscheme

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0620"
-   version = "2.0">
+   LastUpgradeVersion = "0500"
+   version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
       buildImplicitDependencies = "YES">
@@ -22,14 +22,14 @@
          </BuildActionEntry>
          <BuildActionEntry
             buildForTesting = "YES"
-            buildForRunning = "NO"
+            buildForRunning = "YES"
             buildForProfiling = "NO"
             buildForArchiving = "NO"
-            buildForAnalyzing = "NO">
+            buildForAnalyzing = "YES">
             <BuildableReference
                BuildableIdentifier = "primary"
                BlueprintIdentifier = "D0C22BEE179CC00E00158214"
-               BuildableName = "SquirrelTests.xctest"
+               BuildableName = "SquirrelTests.octest"
                BlueprintName = "SquirrelTests"
                ReferencedContainer = "container:Squirrel.xcodeproj">
             </BuildableReference>
@@ -39,56 +39,30 @@
    <TestAction
       selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
-      shouldUseLaunchSchemeArgsEnv = "NO"
-      buildConfiguration = "Debug">
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      buildConfiguration = "Test">
       <Testables>
          <TestableReference
             skipped = "NO">
             <BuildableReference
                BuildableIdentifier = "primary"
                BlueprintIdentifier = "D0C22BEE179CC00E00158214"
-               BuildableName = "SquirrelTests.xctest"
+               BuildableName = "SquirrelTests.octest"
                BlueprintName = "SquirrelTests"
                ReferencedContainer = "container:Squirrel.xcodeproj">
             </BuildableReference>
          </TestableReference>
       </Testables>
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "D0C22BD6179CC00E00158214"
-            BuildableName = "Squirrel.framework"
-            BlueprintName = "Squirrel"
-            ReferencedContainer = "container:Squirrel.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
-      <EnvironmentVariables>
-         <EnvironmentVariable
-            key = "FORCE_APP_IDENTIFIER"
-            value = "com.github.Squirrel.SquirrelTests"
-            isEnabled = "YES">
-         </EnvironmentVariable>
-      </EnvironmentVariables>
    </TestAction>
    <LaunchAction
-      selectedDebuggerIdentifier = ""
-      selectedLauncherIdentifier = "Xcode.IDEFoundation.Launcher.PosixSpawn"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       launchStyle = "0"
       useCustomWorkingDirectory = "NO"
       buildConfiguration = "Debug"
       ignoresPersistentStateOnLaunch = "NO"
       debugDocumentVersioning = "YES"
-      debugXPCServices = "NO"
       allowLocationSimulation = "YES">
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "D0C22BD6179CC00E00158214"
-            BuildableName = "Squirrel.framework"
-            BlueprintName = "Squirrel"
-            ReferencedContainer = "container:Squirrel.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
       <EnvironmentVariables>
          <EnvironmentVariable
             key = "SQRLUpdateFromURL"
@@ -105,15 +79,6 @@
       useCustomWorkingDirectory = "NO"
       buildConfiguration = "Profile"
       debugDocumentVersioning = "YES">
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "D0C22BD6179CC00E00158214"
-            BuildableName = "Squirrel.framework"
-            BlueprintName = "Squirrel"
-            ReferencedContainer = "container:Squirrel.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
    </ProfileAction>
    <AnalyzeAction
       buildConfiguration = "Debug">

Squirrel.xcodeproj/xcshareddata/xcschemes/TestApplication.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0620"
+   LastUpgradeVersion = "0500"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -48,8 +48,7 @@
       ignoresPersistentStateOnLaunch = "NO"
       debugDocumentVersioning = "YES"
       allowLocationSimulation = "YES">
-      <BuildableProductRunnable
-         runnableDebuggingMode = "0">
+      <BuildableProductRunnable>
          <BuildableReference
             BuildableIdentifier = "primary"
             BlueprintIdentifier = "D08D4E0B17B451500012B22D"
@@ -67,8 +66,7 @@
       useCustomWorkingDirectory = "NO"
       buildConfiguration = "Release"
       debugDocumentVersioning = "YES">
-      <BuildableProductRunnable
-         runnableDebuggingMode = "0">
+      <BuildableProductRunnable>
          <BuildableReference
             BuildableIdentifier = "primary"
             BlueprintIdentifier = "D08D4E0B17B451500012B22D"

Squirrel.xcodeproj/xcshareddata/xcschemes/shipit.xcscheme

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
-   LastUpgradeVersion = "0620"
+   LastUpgradeVersion = "0500"
    version = "1.3">
    <BuildAction
       parallelizeBuildables = "YES"
@@ -20,6 +20,20 @@
                ReferencedContainer = "container:Squirrel.xcodeproj">
             </BuildableReference>
          </BuildActionEntry>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "NO"
+            buildForArchiving = "NO"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "D0C22BEE179CC00E00158214"
+               BuildableName = "SquirrelTests.octest"
+               BlueprintName = "SquirrelTests"
+               ReferencedContainer = "container:Squirrel.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
       </BuildActionEntries>
    </BuildAction>
    <TestAction
@@ -39,15 +53,6 @@
       ignoresPersistentStateOnLaunch = "NO"
       debugDocumentVersioning = "YES"
       allowLocationSimulation = "YES">
-      <MacroExpansion>
-         <BuildableReference
-            BuildableIdentifier = "primary"
-            BlueprintIdentifier = "D014AC0017B97885007D79D0"
-            BuildableName = "ShipIt"
-            BlueprintName = "ShipIt"
-            ReferencedContainer = "container:Squirrel.xcodeproj">
-         </BuildableReference>
-      </MacroExpansion>
       <AdditionalOptions>
       </AdditionalOptions>
    </LaunchAction>

Squirrel.xcworkspace/contents.xcworkspacedata

@@ -1,22 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<Workspace
-   version = "1.0">
-   <FileRef
-      location = "group:Squirrel.xcodeproj">
-   </FileRef>
-   <FileRef
-      location = "group:Carthage/Checkouts/Mantle/Mantle.xcodeproj">
-   </FileRef>
-   <FileRef
-      location = "group:Carthage/Checkouts/ReactiveCocoa/ReactiveCocoa.xcodeproj">
-   </FileRef>
-   <FileRef
-      location = "group:External/OHHTTPStubs/OHHTTPStubs/OHHTTPStubs.xcodeproj">
-   </FileRef>
-   <FileRef
-      location = "group:Carthage/Checkouts/Quick/Quick.xcodeproj">
-   </FileRef>
-   <FileRef
-      location = "group:Carthage/Checkouts/Nimble/Nimble.xcodeproj">
-   </FileRef>
-</Workspace>

Squirrel/NSData+SQRLExtensions.h

@@ -0,0 +1,19 @@
+//
+//  NSData+SQRLExtensions.h
+//  Squirrel
+//
+//  Created by Keith Duncan on 21/01/2014.
+//  Copyright (c) 2014 GitHub. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface NSData (SQRLExtensions)
+
+// Returns an NSData for the SHA1 hash of the receiver.
+- (NSData *)sqrl_SHA1Hash;
+
+// Returns the base16 encoding of the receiver.
+- (NSString *)sqrl_base16String;
+
+@end

Squirrel/NSData+SQRLExtensions.m

@@ -0,0 +1,31 @@
+//
+//  NSData+SQRLExtensions.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 21/01/2014.
+//  Copyright (c) 2014 GitHub. All rights reserved.
+//
+
+#import "NSData+SQRLExtensions.h"
+
+#import <CommonCrypto/CommonCrypto.h>
+
+@implementation NSData (SQRLExtensions)
+
+- (NSData *)sqrl_SHA1Hash {
+	unsigned char hash[CC_SHA1_DIGEST_LENGTH];
+	CC_SHA1(self.bytes, (CC_LONG)self.length, hash);
+	return [NSData dataWithBytes:hash length:sizeof(hash) / sizeof(*hash)];
+}
+
+- (NSString *)sqrl_base16String {
+	NSMutableString *base16 = [NSMutableString stringWithCapacity:self.length * 2];
+	uint8_t *bytes = (uint8_t *)self.bytes;
+	for (NSUInteger idx = 0; idx < self.length; idx++) {
+		uint8_t byte = *(bytes + idx);
+		[base16 appendFormat:@"%02hhx", byte];
+	}
+	return base16;
+}
+
+@end

Squirrel/NSHTTPURLResponse+SQRLExtensions.h

@@ -0,0 +1,18 @@
+//
+//  NSHTTPURLResponse+SQRLExtensions.h
+//  Squirrel
+//
+//  Created by Keith Duncan on 04/12/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface NSHTTPURLResponse (SQRLExtensions)
+
+// Case insensitively look up a header field value.
+//
+// Returns the value of the header if present or nil otherwise.
+- (NSString *)sqrl_valueForHTTPHeaderField:(NSString *)field;
+
+@end

Squirrel/NSHTTPURLResponse+SQRLExtensions.m

@@ -0,0 +1,26 @@
+//
+//  NSHTTPURLResponse+SQRLExtensions.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 04/12/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "NSHTTPURLResponse+SQRLExtensions.h"
+
+#import <ReactiveCocoa/ReactiveCocoa.h>
+
+@implementation NSHTTPURLResponse (SQRLExtensions)
+
+- (NSString *)sqrl_valueForHTTPHeaderField:(NSString *)field {
+	return [[[self.allHeaderFields.rac_signal
+		filter:^ BOOL (RACTuple *keyValuePair) {
+			return [keyValuePair[0] caseInsensitiveCompare:field] == NSOrderedSame;
+		}]
+		reduceEach:^(NSString *key, NSString *value) {
+			return value;
+		}]
+		first];
+}
+
+@end

Squirrel/RACSignal+SQRLFileManagerExtensions.h

@@ -0,0 +1,15 @@
+//
+//  RACSignal+SQRLFileManagerExtensions.h
+//  Squirrel
+//
+//  Created by Keith Duncan on 21/01/2014.
+//  Copyright (c) 2014 GitHub. All rights reserved.
+//
+
+#import <ReactiveCocoa/ReactiveCocoa.h>
+
+@interface RACSignal (SQRLFileManagerExtensions)
+
+- (RACSignal *)sqrl_tryCreateDirectory;
+
+@end

Squirrel/RACSignal+SQRLFileManagerExtensions.m

@@ -0,0 +1,21 @@
+//
+//  RACSignal+SQRLFileManagerExtensions.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 21/01/2014.
+//  Copyright (c) 2014 GitHub. All rights reserved.
+//
+
+#import "RACSignal+SQRLFileManagerExtensions.h"
+
+@implementation RACSignal (SQRLFileManagerExtensions)
+
+- (RACSignal *)sqrl_tryCreateDirectory {
+	return [[self
+		try:^(NSURL *directoryURL, NSError **errorRef) {
+			return [NSFileManager.defaultManager createDirectoryAtURL:directoryURL withIntermediateDirectories:YES attributes:nil error:errorRef];
+		}]
+		setNameWithFormat:@"%@ -sqrl_tryCreateDirectory", self];
+}
+
+@end

Squirrel/RACSignal+SQRLTransactionExtensions.h

@@ -6,7 +6,7 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <ReactiveCocoa/RACSignal.h>
+#import <ReactiveCocoa/ReactiveCocoa.h>
 
 @interface RACSignal (SQRLTransactionExtensions)
 

Squirrel/RACSignal+SQRLTransactionExtensions.m

@@ -7,8 +7,6 @@
 //
 
 #import "RACSignal+SQRLTransactionExtensions.h"
-
-#import <ReactiveCocoa/RACDisposable.h>
 #import <IOKit/pwr_mgt/IOPMLib.h>
 
 // How long before power assertions time out.
@@ -99,15 +97,12 @@ static RACDisposable *SQRLCreateTransaction(NSString *name, NSString *descriptio
 		va_end(args);
 	}
 
-	return [[RACSignal createSignal:^(id<RACSubscriber> subscriber) {
-		RACDisposable *transactionDisposable = SQRLCreateTransaction(name, description);
-		RACDisposable *subscriptionDisposable = [self subscribe:subscriber];
-
-		return [RACDisposable disposableWithBlock:^{
-			[subscriptionDisposable dispose];
-			[transactionDisposable dispose];
-		}];
-	}] setNameWithFormat:@"[%@] -sqrl_addTransactionWithName: %@ description: %@", self.name, name, description];
+	return [[RACSignal
+		create:^(id<RACSubscriber> subscriber) {
+			[subscriber.disposable addDisposable:SQRLCreateTransaction(name, description)];
+			[self subscribe:subscriber];
+		}]
+		setNameWithFormat:@"[%@] -sqrl_addTransactionWithName: %@ description: %@", self.name, name, description];
 }
 
 - (RACSignal *)sqrl_addSubscriptionTransactionWithName:(NSString *)name description:(NSString *)descriptionFormat, ... {
@@ -119,13 +114,13 @@ static RACDisposable *SQRLCreateTransaction(NSString *name, NSString *descriptio
 		va_end(args);
 	}
 
-	return [[RACSignal createSignal:^(id<RACSubscriber> subscriber) {
-		RACDisposable *transactionDisposable = SQRLCreateTransaction(name, description);
-		RACDisposable *subscriptionDisposable = [self subscribe:subscriber];
-		[transactionDisposable dispose];
-
-		return subscriptionDisposable;
-	}] setNameWithFormat:@"[%@] -sqrl_addSubscriptionTransactionWithName: %@ description: %@", self.name, name, description];
+	return [[RACSignal
+		create:^(id<RACSubscriber> subscriber) {
+			RACDisposable *transactionDisposable = SQRLCreateTransaction(name, description);
+			[self subscribe:subscriber];
+			[transactionDisposable dispose];
+		}]
+		setNameWithFormat:@"[%@] -sqrl_addSubscriptionTransactionWithName: %@ description: %@", self.name, name, description];
 }
 
 @end

Squirrel/SQRLAuthorization.h

@@ -1,27 +0,0 @@
-//
-//  SQRLAuthorization.h
-//  Squirrel
-//
-//  Created by Keith Duncan on 06/01/2014.
-//  Copyright (c) 2014 GitHub. All rights reserved.
-//
-
-#import <Foundation/Foundation.h>
-
-#import <Security/Security.h>
-
-// Wraps an AuthorizationRef.
-@interface SQRLAuthorization : NSObject
-
-// Designated initializer.
-//
-// authorization - Must not be NULL, the returned object assumes ownership of
-//                 the passed authorization.
-//
-// Returns an object which ties the `authorization` argument to the returned
-// object's lifetime.
-- (instancetype)initWithAuthorization:(AuthorizationRef)authorization;
-
-@property (readonly, nonatomic, assign) AuthorizationRef authorization;
-
-@end

Squirrel/SQRLAuthorization.m

@@ -1,28 +0,0 @@
-//
-//  SQRLAuthorization.m
-//  Squirrel
-//
-//  Created by Keith Duncan on 06/01/2014.
-//  Copyright (c) 2014 GitHub. All rights reserved.
-//
-
-#import "SQRLAuthorization.h"
-
-@implementation SQRLAuthorization
-
-- (instancetype)initWithAuthorization:(AuthorizationRef)authorization {
-	NSParameterAssert(authorization != NULL);
-
-	self = [self init];
-	if (self == nil) return nil;
-
-	_authorization = authorization;
-
-	return self;
-}
-
-- (void)dealloc {
-	if (_authorization != NULL) AuthorizationFree(_authorization, kAuthorizationFlagDestroyRights);
-}
-
-@end

Squirrel/SQRLCodeSignature.h

@@ -21,44 +21,32 @@ extern const NSInteger SQRLCodeSignatureErrorCouldNotCreateStaticCode;
 
 @class RACSignal;
 
-// Implements the verification of Apple code signatures and requirements.
+// Implements the verification of Apple code signatures.
 @interface SQRLCodeSignature : MTLModel
 
 // A serialized version of the `SecRequirementRef` that the receiver was
 // initialized with.
 @property (nonatomic, copy, readonly) NSData *requirementData;
 
-// Determines the designated requirement of the currently-executing application.
-// The returned code signature can be used to verify that a bundle is code sign
-// valid and meets the designated requirement of the current application.
+// Determines the code signature of the currently-executing application.
 //
 // error - If not NULL, set to any error that occurs.
 //
 // Returns a `SQRLCodeSignature`, or nil if an error occurs retrieving the
-// designated requirement for the running code.
+// signature for the running code.
 + (instancetype)currentApplicationSignature:(NSError **)error;
 
-// Determines the designated requirement of the specified bundle. The returned
-// code signature can be used to verify that an arbitrary bundle is valid and
-// meets the designated requirement of `bundle`.
+// Initializes the receiver with the given requirement.
 //
-// bundleURL - Must not be nil, the location of a bundle directory structure
-//             which has been code signed and includes a designated requirement.
-//             This bundle's designated requirement is used when verifying other
-//             bundles.
-// error     - If not NULL, set to any error that occurs.
-//
-// Returns a `SQRLCodeSignature`, or nil if an error occurs retrieving the
-// designated requirement of the bundle at `bundleURL`.
-+ (instancetype)signatureWithBundle:(NSURL *)bundleURL error:(NSError **)error;
+// requirement - The code requirement for tested bundles. This must not be NULL.
+- (id)initWithRequirement:(SecRequirementRef)requirement;
 
-// Verifies the code signature of the specified bundle and verifies that the
-// bundle meets the receiver's requirement.
+// Verifies that the code signature of the specified bundle matches the receiver.
 //
 // bundleURL - The URL to the bundle to verify on disk. This must not be nil.
 //
 // Returns a signal which will synchronously send completed on success, or error
-// if the requirement was not verified successfully.
+// if the code signature was not verified successfully.
 - (RACSignal *)verifyBundleAtURL:(NSURL *)bundleURL;
 
 @end

Squirrel/SQRLCodeSignature.m

@@ -7,11 +7,8 @@
 //
 
 #import "SQRLCodeSignature.h"
-
-#import "EXTKeyPathCoding.h"
-#import "EXTScope.h"
-#import <ReactiveCocoa/RACSignal+Operations.h>
-#import <ReactiveCocoa/RACSubscriber.h>
+#import <ReactiveCocoa/EXTScope.h>
+#import <ReactiveCocoa/ReactiveCocoa.h>
 #import <Security/Security.h>
 
 NSString * const SQRLCodeSignatureErrorDomain = @"SQRLCodeSignatureErrorDomain";
@@ -22,14 +19,9 @@ const NSInteger SQRLCodeSignatureErrorCouldNotCreateStaticCode = -2;
 @interface SQRLCodeSignature ()
 
 // A `SecRequirementRef` that tested bundles must satisfy.
-@property (atomic, strong) id requirement;
-
-// Initializes the receiver with the given requirement.
 //
-// This is the designated initializer for this class.
-//
-// requirement - The code requirement for tested bundles. This must not be NULL.
-- (id)initWithRequirement:(SecRequirementRef)requirement;
+// This property is automatically retained.
+@property (atomic) id requirement;
 
 @end
 
@@ -45,49 +37,8 @@ const NSInteger SQRLCodeSignatureErrorCouldNotCreateStaticCode = -2;
 
 #pragma mark Lifecycle
 
-+ (instancetype)currentApplicationSignature:(NSError **)errorRef {
-	SecCodeRef staticCode = NULL;
-	OSStatus error = SecCodeCopySelf(kSecCSDefaultFlags, &staticCode);
-	if (error != noErr) {
-		if (errorRef != NULL) *errorRef = [NSError errorWithDomain:NSOSStatusErrorDomain code:error userInfo:nil];
-		return nil;
-	}
-
-	@onExit {
-		CFRelease(staticCode);
-	};
-
-	return [self signatureWithCode:staticCode error:errorRef];
-}
-
-+ (instancetype)signatureWithBundle:(NSURL *)bundleURL error:(NSError **)errorRef {
-	SecStaticCodeRef bundleCode = NULL;
-	OSStatus error = SecStaticCodeCreateWithPath((__bridge CFURLRef)bundleURL, kSecCSDefaultFlags, &bundleCode);
-	if (error != noErr) {
-		if (errorRef != NULL) *errorRef = [NSError errorWithDomain:NSOSStatusErrorDomain code:error userInfo:nil];
-		return nil;
-	}
-
-	@onExit {
-		CFRelease(bundleCode);
-	};
-
-	return [self signatureWithCode:bundleCode error:errorRef];
-}
-
-+ (instancetype)signatureWithCode:(SecStaticCodeRef)code error:(NSError **)errorRef {
-	SecRequirementRef designatedRequirement = NULL;
-	OSStatus error = SecCodeCopyDesignatedRequirement(code, kSecCSDefaultFlags, &designatedRequirement);
-	if (error != noErr) {
-		if (errorRef != NULL) *errorRef = [NSError errorWithDomain:NSOSStatusErrorDomain code:error userInfo:nil];
-		return nil;
-	}
-
-	@onExit {
-		CFRelease(designatedRequirement);
-	};
-
-	return [[SQRLCodeSignature alloc] initWithRequirement:designatedRequirement];
++ (instancetype)currentApplicationSignature:(NSError **)error {
+	return [self modelWithDictionary:nil error:error];
 }
 
 - (id)initWithRequirement:(SecRequirementRef)requirement {
@@ -98,12 +49,41 @@ const NSInteger SQRLCodeSignatureErrorCouldNotCreateStaticCode = -2;
 	} error:NULL];
 }
 
+- (id)initWithDictionary:(NSDictionary *)dictionary error:(NSError **)error {
+	self = [super initWithDictionary:dictionary error:error];
+	if (self == nil) return nil;
+
+	if (self.requirement == nil) {
+		SecCodeRef staticCode = NULL;
+		OSStatus result = SecCodeCopySelf(kSecCSDefaultFlags, &staticCode);
+		@onExit {
+			if (staticCode != NULL) CFRelease(staticCode);
+		};
+
+		if (result != noErr) {
+			if (error != NULL) *error = [NSError errorWithDomain:NSOSStatusErrorDomain code:result userInfo:nil];
+			return nil;
+		}
+
+		SecRequirementRef req = NULL;
+		result = SecCodeCopyDesignatedRequirement(staticCode, kSecCSDefaultFlags, &req);
+		self.requirement = CFBridgingRelease(req);
+
+		if (result != noErr) {
+			if (error != NULL) *error = [NSError errorWithDomain:NSOSStatusErrorDomain code:result userInfo:nil];
+			return nil;
+		}
+	}
+
+	return self;
+}
+
 #pragma mark Verification
 
 - (RACSignal *)verifyBundleAtURL:(NSURL *)bundleURL {
 	NSParameterAssert(bundleURL != nil);
 
-	return [[RACSignal createSignal:^ RACDisposable * (id<RACSubscriber> subscriber) {
+	return [[RACSignal create:^(id<RACSubscriber> subscriber) {
 		SecStaticCodeRef staticCode = NULL;
 		
 		OSStatus result = SecStaticCodeCreateWithPath((__bridge CFURLRef)bundleURL, kSecCSDefaultFlags, &staticCode);
@@ -120,8 +100,10 @@ const NSInteger SQRLCodeSignatureErrorCouldNotCreateStaticCode = -2;
 			if (failureReason != nil) userInfo[NSLocalizedFailureReasonErrorKey] = failureReason;
 			
 			[subscriber sendError:[NSError errorWithDomain:SQRLCodeSignatureErrorDomain code:SQRLCodeSignatureErrorCouldNotCreateStaticCode userInfo:userInfo]];
-			return nil;
+			return;
 		}
+
+		if (subscriber.disposable.disposed) return;
 		
 		CFErrorRef validityError = NULL;
 		result = SecStaticCodeCheckValidityWithErrors(staticCode, kSecCSCheckAllArchitectures, (__bridge SecRequirementRef)self.requirement, &validityError);
@@ -139,11 +121,10 @@ const NSInteger SQRLCodeSignatureErrorCouldNotCreateStaticCode = -2;
 			if (validityError != NULL) userInfo[NSUnderlyingErrorKey] = (__bridge NSError *)validityError;
 			
 			[subscriber sendError:[NSError errorWithDomain:SQRLCodeSignatureErrorDomain code:SQRLCodeSignatureErrorDidNotPass userInfo:userInfo]];
-			return nil;
+			return;
 		}
 		
 		[subscriber sendCompleted];
-		return nil;
 	}] setNameWithFormat:@"-verifyCodeSignatureOfBundle: %@", bundleURL];
 }
 

Squirrel/SQRLDirectoryManager.h

@@ -6,16 +6,13 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Cocoa/Cocoa.h>
+#import <Foundation/Foundation.h>
 
 @class RACSignal;
 
 // Provides the file locations that Squirrel/ShipIt use.
 @interface SQRLDirectoryManager : NSObject
 
-// The application identifier to use in file locations.
-@property (nonatomic, copy, readonly) NSString *applicationIdentifier;
-
 // Returns the shared `SQRLDirectoryManager` for the running application, based
 // on the bundle identifier or application name.
 + (instancetype)currentApplicationManager;
@@ -29,14 +26,27 @@
 //                 on-disk locations for. This must not be nil.
 - (instancetype)initWithApplicationIdentifier:(NSString *)appIdentifier;
 
-// Finds or creates an Application Support folder.
+// Finds or creates an Application Support subdirectory for the receiver’s
+// application identifier.
 //
 // Returns a signal which synchronously sends a URL then completes, or errors.
-- (RACSignal *)applicationSupportURL;
+@property (readonly, nonatomic) RACSignal *applicationSupportURL;
+
+// Finds or creates a downloads directory to store update downloads in prior to
+// installation. This is an applicationSupportURL subdirectory.
+//
+// Returns a signal which sends a URL then completes, or errors.
+@property (readonly, nonatomic) RACSignal *downloadDirectoryURL;
+
+// Creates a new directory to unpack a downloaded update into prior to
+// installation. This is an applicationSupportURL subdirectory.
+//
+// Returns a signal which sends a URL then completes, or errors.
+- (RACSignal *)createUniqueUpdateDirectoryURL;
 
 // Determines where archived `SQRLShipItState` should be saved.
 //
 // Returns a signal which synchronously sends a URL then completes, or errors.
-- (RACSignal *)shipItStateURL;
+@property (readonly, nonatomic) RACSignal *shipItStateURL;
 
 @end

Squirrel/SQRLDirectoryManager.m

@@ -7,8 +7,16 @@
 //
 
 #import "SQRLDirectoryManager.h"
+#import <ReactiveCocoa/ReactiveCocoa.h>
+#import <ReactiveCocoa/EXTScope.h>
+#import "RACSignal+SQRLFileManagerExtensions.h"
 
-#import <ReactiveCocoa/RACSignal+Operations.h>
+@interface SQRLDirectoryManager ()
+
+// The application identifier to use in file locations.
+@property (nonatomic, copy, readonly) NSString *applicationIdentifier;
+
+@end
 
 @implementation SQRLDirectoryManager
 
@@ -24,7 +32,7 @@
 		// Should only fallback to when running under otest, where
 		// NSBundle.mainBundle doesn't return useful data.
 		if (identifier == nil) {
-			identifier = NSProcessInfo.processInfo.environment[@"FORCE_APP_IDENTIFIER"];
+			identifier = NSRunningApplication.currentApplication.localizedName;
 		}
 
 		NSAssert(identifier != nil, @"Could not automatically determine the current application's identifier");
@@ -47,25 +55,65 @@
 
 #pragma mark Folder URLs
 
++ (NSString *)fileSystemNameForIdentifier:(NSString *)identifier {
+	// Periods are problematic in the filesystem because they denote file type.
+	// A directory can become a package which can be undesirable.
+	return [identifier stringByReplacingOccurrencesOfString:@"." withString:@"~"];
+}
+
 - (RACSignal *)applicationSupportURL {
-	return [[RACSignal
+	return [[[[RACSignal
 		defer:^{
 			NSError *error = nil;
-			NSURL *folderURL = [NSFileManager.defaultManager URLForDirectory:NSApplicationSupportDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:YES error:&error];
-			if (folderURL == nil) {
+			NSURL *directoryURL = [NSFileManager.defaultManager URLForDirectory:NSApplicationSupportDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:YES error:&error];
+			if (directoryURL == nil) {
 				return [RACSignal error:error];
 			}
 
-			folderURL = [folderURL URLByAppendingPathComponent:self.applicationIdentifier];
-			if (![NSFileManager.defaultManager createDirectoryAtURL:folderURL withIntermediateDirectories:YES attributes:nil error:&error]) {
-				return [RACSignal error:error];
-			}
-
-			return [RACSignal return:folderURL];
+			return [RACSignal return:directoryURL];
 		}]
+		map:^ (NSURL *directoryURL) {
+			RACSignal *identifierComponents = [@[ self.applicationIdentifier, @"com.github.Squirrel" ].rac_signal
+				map:^(NSString *name) {
+					return [self.class fileSystemNameForIdentifier:name];
+				}];
+
+			RACSignal *pathComponents = [directoryURL.pathComponents.rac_signal concat:identifierComponents];
+			return [NSURL fileURLWithPathComponents:[pathComponents array]];
+		}]
+		sqrl_tryCreateDirectory]
 		setNameWithFormat:@"%@ -applicationSupportURL", self];
 }
 
+- (RACSignal *)downloadDirectoryURL {
+	return [[[[self
+		applicationSupportURL]
+		map:^(NSURL *directoryURL) {
+			return [directoryURL URLByAppendingPathComponent:@"downloads"];
+		}]
+		sqrl_tryCreateDirectory]
+		setNameWithFormat:@"%@ -downloadDirectoryURL", self];
+}
+
+- (RACSignal *)createUniqueUpdateDirectoryURL {
+	return [[[[self
+		applicationSupportURL]
+		map:^(NSURL *directoryURL) {
+			// noindex so that Spotlight doesn't pick up apps pending update and
+			// add them to the Launch Services database.
+			return [[directoryURL URLByAppendingPathComponent:NSProcessInfo.processInfo.globallyUniqueString] URLByAppendingPathExtension:@"noindex"];
+		}]
+		try:^(NSURL *directoryURL, NSError **errorRef) {
+			// Explicitly just provide the owner with permission, discarding the
+			// current umask. This matches the `mkdtemp` behaviour.
+			NSDictionary *directoryAttributes = @{
+				NSFilePosixPermissions: @(S_IRWXU),
+			};
+			return [NSFileManager.defaultManager createDirectoryAtURL:directoryURL withIntermediateDirectories:YES attributes:directoryAttributes error:errorRef];
+		}]
+		setNameWithFormat:@"%@ -createUniqueUpdateDirectoryURL", self];
+}
+
 - (RACSignal *)shipItStateURL {
 	return [[[self
 		applicationSupportURL]

Squirrel/SQRLDownload+Private.h

@@ -0,0 +1,21 @@
+//
+//  SQRLDownload+Private.h
+//  Squirrel
+//
+//  Created by Keith Duncan on 21/01/2014.
+//  Copyright (c) 2014 GitHub. All rights reserved.
+//
+
+#import "SQRLDownload.h"
+
+@interface SQRLDownload ()
+
+// Designated initialiser.
+//
+// request - Must not be nil. The request this download is for.
+// fileURL - Must not be nil. The file location to save received data to.
+//
+// Returns an initialised download suitable for saving response data.
+- (instancetype)initWithRequest:(NSURLRequest *)request fileURL:(NSURL *)fileURL;
+
+@end

Squirrel/SQRLDownload.h

@@ -0,0 +1,31 @@
+//
+//  SQRLDownload.h
+//  Squirrel
+//
+//  Created by Keith Duncan on 21/11/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import <Mantle/Mantle.h>
+
+@class RACSignal;
+
+// A download is a file which holds the response body for a request and can be
+// resumed by a subsequent request if the initial transfer is interrupted.
+//
+// Don't create a download directly, instead retrieve one from
+// `SQRLDownloadManager`.
+@interface SQRLDownload : MTLModel
+
+// The `request` the receiver was initialised with.
+@property (readonly, copy, nonatomic) NSURLRequest *request;
+
+// The `fileURL` the receiver was initialised with.
+@property (readonly, copy, nonatomic) NSURL *fileURL;
+
+// Calculate a request suitable for resuming the download.
+//
+// Returns a signal which sends an `NSURLRequest` then completes.
+@property (readonly, nonatomic) RACSignal *resumableRequest;
+
+@end

Squirrel/SQRLDownload.m

@@ -0,0 +1,29 @@
+//
+//  SQRLDownload.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 21/11/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "SQRLDownload.h"
+#import "SQRLDownload+Private.h"
+
+#import <ReactiveCocoa/ReactiveCocoa.h>
+
+@implementation SQRLDownload
+
+- (instancetype)initWithRequest:(NSURLRequest *)request fileURL:(NSURL *)fileURL {
+	return [self initWithDictionary:@{
+		@keypath(self.request): request,
+		@keypath(self.fileURL): fileURL,
+	} error:NULL];
+}
+
+- (RACSignal *)resumableRequest {
+	return [[RACSignal
+		return:self.request]
+		setNameWithFormat:@"%@ %s", self, sel_getName(_cmd)];
+}
+
+@end

Squirrel/SQRLDownloadManager.h

@@ -0,0 +1,61 @@
+//
+//  SQRLDownloadController.h
+//  Squirrel
+//
+//  Created by Keith Duncan on 26/09/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@class SQRLDownload;
+@class SQRLResumableDownload;
+@class RACSignal;
+@class SQRLDirectoryManager;
+
+// Stores metadata for download resumption, and manages the disk locations for
+// where they're stored.
+@interface SQRLDownloadManager : NSObject
+
+// Default download manager, initializes a download manager with the current
+// application directory manager. Stores downloads in
+// `directoryManager.downloadDirectoryURL`.
++ (instancetype)defaultDownloadManager;
+
+// Designated initialiser.
+//
+// directoryManager - Must not be nil.
+//
+// Returns a download manager which can resume previously started downloads for
+// the initialised directory manager's application.
+- (instancetype)initWithDirectoryManager:(SQRLDirectoryManager *)directoryManager;
+
+// Clean the resumable download state, removes downloaded data and tracking
+// state.
+//
+// Returns a signal which errors or completes when all file operations have been
+// attempted.
+- (RACSignal *)removeAllResumableDownloads;
+
+// Retrieve a previously started download, or initialise a new download.
+//
+// Previously started downloads may have been removed and require
+// reinitialising.
+//
+// request - The request you are performing and require a disk location to save
+//           the response body to. Must not be nil.
+//
+// Returns a signal which sends an `SQRLDownload` object then completes, or
+// errors.
+- (RACSignal *)downloadForRequest:(NSURLRequest *)request;
+
+// Store metadata for a download so that it can be resumed later.
+//
+// download - The download being stored for future resumption. Must not be nil.
+// request  - The request for which the download can be resumed. Must not be
+//            nil.
+//
+// Returns a signal which completes or errors.
+- (RACSignal *)setDownload:(SQRLResumableDownload *)download forRequest:(NSURLRequest *)request;
+
+@end

Squirrel/SQRLDownloadManager.m

@@ -0,0 +1,239 @@
+//
+//  SQRLDownloadController.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 26/09/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "SQRLDownloadManager.h"
+
+#import <ReactiveCocoa/ReactiveCocoa.h>
+
+#import "SQRLDirectoryManager.h"
+#import "SQRLDownload.h"
+#import "SQRLDownload+Private.h"
+#import "SQRLResumableDownload.h"
+
+#import "NSData+SQRLExtensions.h"
+
+@interface SQRLDownloadManager ()
+@property (nonatomic, strong, readonly) SQRLDirectoryManager *directoryManager;
+@property (nonatomic, assign, readonly) dispatch_queue_t queue;
+
+// Reads the download index.
+//
+// Returns a signal which sends the download index at time of read then
+// completes, or errors.
+- (RACSignal *)readDownloadIndex;
+
+// Write a new download index.
+//
+// block - Map from the old download index to the new download index. Writing
+//         is serialised, subsequent writers will receive the output of the
+//         previous map block. If the output of the map is equal to the input
+//         no write is attempted and the returned signal completes.
+//
+// Returns a signal which completes or errors.
+- (RACSignal *)writeDownloadIndexWithBlock:(NSDictionary * (^)(NSMutableDictionary *))block;
+@end
+
+@implementation SQRLDownloadManager
+
++ (instancetype)defaultDownloadManager {
+	static SQRLDownloadManager *defaultDownloadManager;
+	static dispatch_once_t defaultDownloadManagerPredicate;
+
+	dispatch_once(&defaultDownloadManagerPredicate, ^{
+		defaultDownloadManager = [[self alloc] initWithDirectoryManager:SQRLDirectoryManager.currentApplicationManager];
+	});
+
+	return defaultDownloadManager;
+}
+
+- (id)initWithDirectoryManager:(SQRLDirectoryManager *)directoryManager {
+	NSParameterAssert(directoryManager != nil);
+
+	self = [super init];
+	if (self == nil) return nil;
+
+	_directoryManager = directoryManager;
+
+	_queue = dispatch_queue_create("com.github.Squirrel.SQRLDownloadManager.queue", DISPATCH_QUEUE_CONCURRENT);
+	dispatch_set_target_queue(_queue, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0));
+
+	return self;
+}
+
+- (void)dealloc {
+	if (_queue != NULL) dispatch_release(_queue);
+}
+
+- (RACSignal *)removeAllResumableDownloads {
+	return [[[RACSignal
+		merge:@[
+			[self downloadStoreIndexFileLocation],
+			[self.directoryManager downloadDirectoryURL]
+		]]
+		flattenMap:^ (NSURL *location) {
+			return [[RACSignal
+				defer:^{
+					NSError *error;
+					BOOL remove = [NSFileManager.defaultManager removeItemAtURL:location error:&error];
+					return (remove ? [RACSignal empty] : [RACSignal error:error]);
+				}]
+				catch:^(NSError *error) {
+					if ([error.domain isEqualToString:NSCocoaErrorDomain] && error.code == NSFileNoSuchFileError) return [RACSignal empty];
+					return [RACSignal error:error];
+				}];
+		}]
+		setNameWithFormat:@"%@ %s", self, sel_getName(_cmd)];
+}
+
+- (RACSignal *)downloadStoreIndexFileLocation {
+	return [[[self.directoryManager
+		applicationSupportURL]
+		map:^(NSURL *directory) {
+			return [directory URLByAppendingPathComponent:@"DownloadIndex.plist"];
+		}]
+		setNameWithFormat:@"%@ %s", self, sel_getName(_cmd)];
+}
+
+- (RACSignal *)readDownloadIndex {
+	return [[[self
+		downloadStoreIndexFileLocation]
+		flattenMap:^(NSURL *location) {
+			return [RACSignal
+				create:^(id<RACSubscriber> subscriber) {
+					dispatch_async(self.queue, ^{
+						if (subscriber.disposable.disposed) return;
+
+						NSError *error;
+						NSDictionary *propertyList = [self readPropertyListWithContentsOfURL:location error:&error];
+						if (propertyList == nil) {
+							[subscriber sendError:error];
+							return;
+						}
+
+						[subscriber sendNext:propertyList];
+						[subscriber sendCompleted];
+					});
+				}];
+		}]
+		setNameWithFormat:@"%@ %s", self, sel_getName(_cmd)];
+}
+
+- (RACSignal *)writeDownloadIndexWithBlock:(NSDictionary * (^)(NSMutableDictionary *))block {
+	NSParameterAssert(block != nil);
+
+	return [[[self
+		downloadStoreIndexFileLocation]
+		flattenMap:^(NSURL *location) {
+			return [RACSignal create:^(id<RACSubscriber> subscriber) {
+				dispatch_barrier_async(self.queue, ^{
+					if (subscriber.disposable.disposed) return;
+
+					NSError *error;
+					NSDictionary *propertyList = [self readPropertyListWithContentsOfURL:location error:&error];
+					if (propertyList == nil) {
+						[subscriber sendError:error];
+						return;
+					}
+
+					NSDictionary *newPropertyList = block([propertyList mutableCopy]);
+					if ([newPropertyList isEqual:propertyList]) {
+						[subscriber sendCompleted];
+						return;
+					}
+
+					NSData *newData = [NSKeyedArchiver archivedDataWithRootObject:newPropertyList];
+					if (newData == nil) {
+						NSDictionary *errorInfo = @{ NSURLErrorKey: location };
+						[subscriber sendError:[NSError errorWithDomain:NSCocoaErrorDomain code:NSPropertyListWriteStreamError userInfo:errorInfo]];
+						return;
+					}
+
+					BOOL write = [newData writeToURL:location options:NSDataWritingAtomic error:&error];
+					if (!write) {
+						[subscriber sendError:error];
+						return;
+					}
+
+					[subscriber sendCompleted];
+				});
+			}];
+		}]
+		setNameWithFormat:@"%@ %s", self, sel_getName(_cmd)];
+}
+
+- (NSDictionary *)readPropertyListWithContentsOfURL:(NSURL *)location error:(NSError **)errorRef {
+	NSData *propertyListData = [NSData dataWithContentsOfURL:location options:NSDataReadingUncached error:NULL];
+	if (propertyListData == nil) {
+		return @{};
+	}
+
+	NSDictionary *propertyList = [NSKeyedUnarchiver unarchiveObjectWithData:propertyListData];
+	if (propertyList == nil) {
+		if (errorRef != NULL) {
+			NSDictionary *errorInfo = @{ NSURLErrorKey: location };
+			*errorRef = [NSError errorWithDomain:NSCocoaErrorDomain code:NSPropertyListReadCorruptError userInfo:errorInfo];
+		}
+		return nil;
+	}
+
+	return propertyList;
+}
+
++ (NSString *)keyForURL:(NSURL *)URL {
+	return URL.absoluteString;
+}
+
++ (NSString *)fileNameForURL:(NSURL *)URL {
+	NSString *key = [self keyForURL:URL];
+	return [[[key dataUsingEncoding:NSUTF8StringEncoding] sqrl_SHA1Hash] sqrl_base16String];
+}
+
+- (RACSignal *)downloadForRequest:(NSURLRequest *)request {
+	NSParameterAssert(request != nil);
+
+	return [[[[self
+		readDownloadIndex]
+		map:^(NSDictionary *index) {
+			NSString *key = [self.class keyForURL:request.URL];
+			return index[key];
+		}]
+		flattenMap:^(SQRLResumableDownload *download) {
+			if (download != nil) return [RACSignal return:download];
+
+			return [[[self.directoryManager
+				downloadDirectoryURL]
+				map:^(NSURL *downloadDirectory) {
+					return [downloadDirectory URLByAppendingPathComponent:[self.class fileNameForURL:request.URL]];
+				}]
+				map:^(NSURL *location) {
+					return [[SQRLDownload alloc] initWithRequest:request fileURL:location];
+				}];
+		}]
+		setNameWithFormat:@"%@ %s", self, sel_getName(_cmd)];
+}
+
+- (RACSignal *)setDownload:(SQRLResumableDownload *)download forRequest:(NSURLRequest *)request {
+	NSParameterAssert(download.response != nil);
+	NSParameterAssert(request != nil);
+
+	return [[self
+		writeDownloadIndexWithBlock:^(NSMutableDictionary *index) {
+			NSString *key = [self.class keyForURL:request.URL];
+
+			if (download != nil) {
+				index[key] = download;
+			} else {
+				[index removeObjectForKey:key];
+			}
+
+			return index;
+		}]
+		setNameWithFormat:@"%@ %s", self, sel_getName(_cmd)];
+}
+
+@end

Squirrel/SQRLDownloadedUpdate.h

@@ -11,7 +11,7 @@
 @class SQRLUpdate;
 
 // A SQRLUpdate that has been successfully downloaded to disk.
-@interface SQRLDownloadedUpdate : MTLModel
+@interface SQRLDownloadedUpdate : MTLModel <MTLJSONSerializing>
 
 // The application bundle representing the downloaded and unarchived update.
 @property (nonatomic, strong, readonly) NSBundle *bundle;

Squirrel/SQRLDownloadedUpdate.m

@@ -7,6 +7,7 @@
 //
 
 #import "SQRLDownloadedUpdate.h"
+#import "SQRLUpdate.h"
 #import <ReactiveCocoa/ReactiveCocoa.h>
 
 @interface SQRLDownloadedUpdate ()
@@ -40,9 +41,15 @@
 #pragma mark MTLJSONSerializing
 
 + (NSDictionary *)JSONKeyPathsByPropertyKey {
-	return [super.JSONKeyPathsByPropertyKey mtl_dictionaryByAddingEntriesFromDictionary:@{
-		@keypath(SQRLDownloadedUpdate.new, bundleURL): NSNull.null
-	}];
+	return @{};
+}
+
++ (NSValueTransformer *)updateJSONTransformer {
+	return [MTLValueTransformer mtl_JSONDictionaryTransformerWithModelClass:SQRLUpdate.class];
+}
+
++ (NSValueTransformer *)bundleURLJSONTransformer {
+	return [NSValueTransformer valueTransformerForName:MTLURLValueTransformerName];
 }
 
 @end

Squirrel/SQRLInstaller+Private.h

@@ -1,17 +0,0 @@
-//
-//  SQRLInstaller+Private.h
-//  Squirrel
-//
-//  Created by Keith Duncan on 08/01/2014.
-//  Copyright (c) 2014 GitHub. All rights reserved.
-//
-
-#import "SQRLInstaller.h"
-
-// The defaults key to store a `SQRLInstallerOwnedBundle` so that a moved bundle
-// can be restored.
-extern NSString * const SQRLInstallerOwnedBundleKey;
-
-// The defaults key to store the number of installation attempts that have been
-// made.
-extern NSString * const SQRLShipItInstallationAttemptsKey;

Squirrel/SQRLInstaller.h

@@ -11,7 +11,7 @@
 // The domain for errors originating within SQRLInstaller.
 extern NSString * const SQRLInstallerErrorDomain;
 
-// There was an error copying the target or update bundle to a backup location.
+// There was an error copying the target bundle to the backup location.
 extern const NSInteger SQRLInstallerErrorBackupFailed;
 
 // There was an error replacing the target bundle with the update.
@@ -34,39 +34,35 @@ extern const NSInteger SQRLInstallerErrorInvalidState;
 // There was an error moving a bundle across volumes.
 extern const NSInteger SQRLInstallerErrorMovingAcrossVolumes;
 
-// There was an error changing the file permissions of the update.
-extern const NSInteger SQRLInstallerErrorChangingPermissions;
+@class RACSignal;
+@class RACAction;
+@class SQRLShipItState;
+@class SQRLDirectoryManager;
 
-@class RACCommand;
-
-// Performs the installation of an update, saving its intermediate state to user
-// defaults.
+// Performs the installation of an update, using the `SQRLShipItState` on disk,
+// as located by `SQRLDirectoryManager`.
 //
 // This class is meant to be used only after the app that will be updated has
 // terminated.
 @interface SQRLInstaller : NSObject
 
-// Initializes an installer using the given application identifier, which is
-// used to scope resumable state stored to user defaults.
+// Attempts to install the update or resume an in-progress installation.
 //
-// applicationIdentifier - The defaults domain in which to store resumable
-//                         state. Must not be nil.
-- (instancetype)initWithApplicationIdentifier:(NSString *)applicationIdentifier;
-
-// When executed with a `SQRLShipItRequest`, attempts to install the update or
-// resume an in-progress installation.
-//
-// Each execution will complete or error on an unspecified scheduler when
+// Returns a signal which completes or errors on an unspecified scheduler when
 // installation has completed or failed.
-@property (nonatomic, strong, readonly) RACCommand *installUpdateCommand;
+- (RACSignal *)installUpdateWithState:(SQRLShipItState *)state;
 
-// When executed with a `SQRLShipItRequest`, aborts an installation, and
-// attempts to restore the old version of the application if necessary.
+// Aborts an installation, and attempts to restore the old version of the
+// application if necessary.
 //
-// This must not be executed while `installUpdateCommand` is executing.
+// This must not be executed while `installUpdateWithState:` is executing.
 //
-// Each execution will complete or error on an unspecified scheduler once
+// Returns a signal while completes or errors on an unspecified scheduler once
 // aborting/recovery has finished.
-@property (nonatomic, strong, readonly) RACCommand *abortInstallationCommand;
+- (RACSignal *)abortInstallationWithState:(SQRLShipItState *)state;
+
+// Initializes an installer using the given directory manager to read and write the
+// state of the installation.
+- (id)initWithDirectoryManager:(SQRLDirectoryManager *)directoryManager;
 
 @end

Squirrel/SQRLInstaller.m

@@ -7,25 +7,17 @@
 //
 
 #import "SQRLInstaller.h"
-
-#import <libkern/OSAtomic.h>
-#import "EXTScope.h"
-#import <ReactiveCocoa/NSEnumerator+RACSequenceAdditions.h>
-#import <ReactiveCocoa/NSObject+RACPropertySubscribing.h>
-#import <ReactiveCocoa/RACCommand.h>
-#import <ReactiveCocoa/RACSequence.h>
-#import <ReactiveCocoa/RACSignal+Operations.h>
-#import <ReactiveCocoa/RACSubscriber.h>
-#import <sys/xattr.h>
-
 #import "NSBundle+SQRLVersionExtensions.h"
 #import "NSError+SQRLVerbosityExtensions.h"
 #import "RACSignal+SQRLTransactionExtensions.h"
 #import "SQRLCodeSignature.h"
 #import "SQRLDirectoryManager.h"
-#import "SQRLShipItRequest.h"
+#import "SQRLShipItState.h"
 #import "SQRLTerminationListener.h"
-#import "SQRLInstallerOwnedBundle.h"
+#import <libkern/OSAtomic.h>
+#import <ReactiveCocoa/EXTScope.h>
+#import <ReactiveCocoa/ReactiveCocoa.h>
+#import <sys/xattr.h>
 
 NSString * const SQRLInstallerErrorDomain = @"SQRLInstallerErrorDomain";
 
@@ -36,58 +28,85 @@ const NSInteger SQRLInstallerErrorInvalidBundleVersion = -4;
 const NSInteger SQRLInstallerErrorMissingInstallationData = -5;
 const NSInteger SQRLInstallerErrorInvalidState = -6;
 const NSInteger SQRLInstallerErrorMovingAcrossVolumes = -7;
-const NSInteger SQRLInstallerErrorChangingPermissions = -8;
 
-NSString * const SQRLShipItInstallationAttemptsKey = @"SQRLShipItInstallationAttempts";
-NSString * const SQRLInstallerOwnedBundleKey = @"SQRLInstallerOwnedBundle";
+// Maps an installer state to a selector to invoke.
+typedef struct {
+	// The state for which the associated method should be invoked.
+	SQRLInstallerState installerState;
+
+	// A method accepting a `SQRLShipItState` argument and returning a cold
+	// signal.
+	//
+	// If NULL, installation should complete.
+	SEL selector;
+} SQRLInstallerDispatchTableEntry;
 
 @interface SQRLInstaller ()
 
-// The defaults domain to store all resumable state in.
-@property (nonatomic, copy, readonly) NSString *applicationIdentifier;
+// Finds the state file to read and write from.
+@property (nonatomic, strong, readonly) SQRLDirectoryManager *directoryManager;
 
-// The bundle currently owned by this installer.
+// Reads the given key from `state`, failing if it's not set.
 //
-// Stores the bundle moved aside by an install request so that the original
-// bundle can be restored to its original location if needed.
-@property (atomic, strong) SQRLInstallerOwnedBundle *ownedBundle;
-
-// Reads the given key from `request`, failing if it's not set.
-//
-// key     - The property key to read from `request`. This must not be nil, and
-//           should refer to a property of object type.
-// request - The request object to read. This must not be nil.
+// key   - The property key to read from `state`. This must not be nil, and
+//         should refer to a property of object type.
+// state - The state object to read. This must not be nil.
 //
 // Returns a signal which synchronously sends the non-nil read value then
 // completes, or errors.
-- (RACSignal *)getRequiredKey:(NSString *)key fromRequest:(SQRLShipItRequest *)request;
+- (RACSignal *)getRequiredKey:(NSString *)key fromState:(SQRLShipItState *)state;
 
-// Moves the updateBundleURL to an owned directory to prevent symlink attack,
-// takes user:group ownership of the bundle, then verifies that it meets the
-// designated requirement of the targetBundleURL.
+// Performs the remaining stages of installation, as specified by `state`.
 //
-// request - The request whose update should be prepared and validated.
+// state - The installation state. This must not be nil.
 //
-// Returns a signal which sends the owned & validated bundle URL then completes,
-// or errors.
-- (RACSignal *)prepareAndValidateUpdateBundleURLForRequest:(SQRLShipItRequest *)request;
+// Returns a signal which will complete or error on an unspecified thread.
+- (RACSignal *)resumeInstallationFromState:(SQRLShipItState *)state;
 
-// Saves a `SQRLInstallerOwnedBundle` for the targetBundleURL to the
-// preferences, then moves the targetBundleURL to an owned directory.
+// Moves the specified bundle to a backup location.
 //
-// request - The request whose target should be removed in preparation of an
-//           update being installed.
+// bundleURL - The URL to the bundle that should be backed up. This must not be
+//             nil.
 //
-// Returns a signal which completes, or errors.
-- (RACSignal *)acquireTargetBundleURLForRequest:(SQRLShipItRequest *)request;
+// Returns a signal which will send the `NSURL` to the proposed backup location
+// as soon as possible, then complete once the bundle has actually been moved.
+- (RACSignal *)backUpBundleAtURL:(NSURL *)bundleURL;
 
-// Deletes a bundle that was moved into place using -moveAndTakeOwnershipOfBundleAtURL:.
+// Deletes a bundle that was backed up using -backUpBundleAtURL:.
 //
-// bundleURL - The URL to the backup bundle, as sent from -moveAndTakeOwnershipOfBundleAtURL:.
+// backupURL - The URL to the backup bundle, as sent from -backUpBundleAtURL:.
 //             This must not be nil.
 //
 // Returns a signal which will synchronously complete or error.
-- (RACSignal *)deleteOwnedBundleAtURL:(NSURL *)bundleURL;
+- (RACSignal *)deleteBackupAtURL:(NSURL *)backupURL;
+
+// Validates the code signature of a bundle, optionally restoring it upon
+// failure.
+//
+// bundleURL       - The URL of the bundle whose code signature should be
+//                   verified. This must not be nil.
+// signature       - The code signature that the bundle must match. This must
+//                   not be nil.
+// backupBundleURL - If not nil, the URL to a bundle that should replace
+//                   `bundleURL` if the code signature does not pass validation.
+//
+// Returns a signal which will synchronously complete if `bundleURL` passes
+// validation, or if the bundle was recovered from `backupBundleURL`. If
+// validation or recovery fails, an error will be sent.
+- (RACSignal *)verifyBundleAtURL:(NSURL *)bundleURL usingSignature:(SQRLCodeSignature *)signature recoveringUsingBackupAtURL:(NSURL *)backupBundleURL;
+
+// Attempts to determine whether a bundle has already been moved on disk.
+//
+// sourceURL - The original URL to the bundle. This must not be nil.
+// targetURL - The proposed destination URL for the bundle. This must not be
+//             nil.
+// signature - The code signature that any item must match in order to be
+//             considered the correct bundle. This must not be nil.
+//
+// Returns a signal which will synchronously send YES if `targetURL` points to
+// a bundle matching the code signature, NO if it doesn't and `sourceURL` still
+// exists, or an error otherwise.
+- (RACSignal *)checkWhetherBundlePreviouslyAtURL:(NSURL *)sourceURL wasInstalledAtURL:(NSURL *)targetURL usingSignature:(SQRLCodeSignature *)signature;
 
 // Moves `sourceURL` to `targetURL`.
 //
@@ -99,7 +118,7 @@ NSString * const SQRLInstallerOwnedBundleKey = @"SQRLInstallerOwnedBundle";
 // sourceURL - The URL to move from. This must not be nil.
 //
 // Retruns a signal which will synchronously complete or error.
-- (RACSignal *)installItemToURL:(NSURL *)targetURL fromURL:(NSURL *)sourceURL;
+- (RACSignal *)installItemAtURL:(NSURL *)targetURL fromURL:(NSURL *)sourceURL;
 
 // Recursively clears the quarantine extended attribute from the given
 // directory.
@@ -113,96 +132,56 @@ NSString * const SQRLInstallerOwnedBundleKey = @"SQRLInstallerOwnedBundle";
 // Returns a signal which will send completed or error on a background thread.
 - (RACSignal *)clearQuarantineForDirectory:(NSURL *)directory;
 
-// Recursively changes the owner and group of the given directory tree to that
-// of the current process, then disables writing for anyone but the owner.
-//
-// directoryURL - The URL to the folder to take ownership of. This must not be
-//                nil.
-//
-// Returns a signal which will synchronously complete or error.
-- (RACSignal *)takeOwnershipOfDirectory:(NSURL *)directoryURL;
-
 @end
 
 @implementation SQRLInstaller
 
 #pragma mark Lifecycle
 
-- (id)initWithApplicationIdentifier:(NSString *)applicationIdentifier {
-	NSParameterAssert(applicationIdentifier != nil);
+- (id)initWithDirectoryManager:(SQRLDirectoryManager *)directoryManager {
+	NSParameterAssert(directoryManager != nil);
 
 	self = [super init];
 	if (self == nil) return nil;
 
-	_applicationIdentifier = [applicationIdentifier copy];
-
-	@weakify(self);
-
-	RACSignal *aborting = [[[[RACObserve(self, abortInstallationCommand)
-		ignore:nil]
-		map:^(RACCommand *command) {
-			return command.executing;
-		}]
-		switchToLatest]
-		setNameWithFormat:@"aborting"];
-
-	_installUpdateCommand = [[RACCommand alloc] initWithEnabled:[aborting not] signalBlock:^(SQRLShipItRequest *request) {
-		@strongify(self);
-		NSParameterAssert(request != nil);
-
-		// Request can be changed between launches, the installer may have
-		// already have an owned bundle, for a previous targetURL.
-		//
-		// If that's the case, we need to abort the previous owned bundle, and
-		// then handle the new install request.
-
-		return [[[[self
-			abortInstall]
-			doError:^(NSError *error) {
-				NSLog(@"Couldn't abort install and restore owned bundle to previous location %@, error %@", self.ownedBundle.originalURL, error.sqrl_verboseDescription);
-			}]
-			catchTo:[RACSignal empty]]
-			then:^{
-				return [self installRequest:request];
-			}];
-	}];
-
-	_abortInstallationCommand = [[RACCommand alloc] initWithEnabled:[self.installUpdateCommand.executing not] signalBlock:^(SQRLShipItRequest *request) {
-		@strongify(self);
-
-		return [self abortInstall];
-	}];
-
+	_directoryManager = directoryManager;
+	
 	return self;
 }
 
-#pragma mark Preferences
+#pragma mark Actions
 
-- (SQRLInstallerOwnedBundle *)ownedBundle {
-	id archiveData = CFBridgingRelease(CFPreferencesCopyValue((__bridge CFStringRef)SQRLInstallerOwnedBundleKey, (__bridge CFStringRef)self.applicationIdentifier, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost));
-	if (![archiveData isKindOfClass:NSData.class]) return nil;
+- (RACSignal *)installUpdateWithState:(SQRLShipItState *)state {
+	NSParameterAssert(state != nil);
 
-	SQRLInstallerOwnedBundle *ownedBundle = [NSKeyedUnarchiver unarchiveObjectWithData:archiveData];
-	if (![ownedBundle isKindOfClass:SQRLInstallerOwnedBundle.class]) return nil;
-
-	return ownedBundle;
+	return [[self
+		resumeInstallationFromState:state]
+		sqrl_addTransactionWithName:NSLocalizedString(@"Updating", nil) description:NSLocalizedString(@"%@ is being updated, and interrupting the process could corrupt the application", nil), state.targetBundleURL.path];
 }
 
-- (void)setOwnedBundle:(SQRLInstallerOwnedBundle *)ownedBundle {
-	NSData *archiveData = (ownedBundle == nil ? nil : [NSKeyedArchiver archivedDataWithRootObject:ownedBundle]);
-	CFPreferencesSetValue((__bridge CFStringRef)SQRLInstallerOwnedBundleKey, (__bridge CFPropertyListRef)archiveData, (__bridge CFStringRef)self.applicationIdentifier, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost);
-	CFPreferencesSynchronize((__bridge CFStringRef)self.applicationIdentifier, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost);
+- (RACSignal *)abortInstallationWithState:(SQRLShipItState *)state {
+	NSParameterAssert(state != nil);
+
+	return [[[RACSignal
+		zip:@[
+			[self getRequiredKey:@keypath(state.targetBundleURL) fromState:state],
+			[self getRequiredKey:@keypath(state.codeSignature) fromState:state]
+		] reduce:^(NSURL *targetBundleURL, SQRLCodeSignature *codeSignature) {
+			return [self verifyBundleAtURL:targetBundleURL usingSignature:codeSignature recoveringUsingBackupAtURL:state.backupBundleURL];
+		}]
+		flatten]
+		sqrl_addTransactionWithName:NSLocalizedString(@"Aborting update", nil) description:NSLocalizedString(@"An update to %@ is being rolled back, and interrupting the process could corrupt the application", nil), state.targetBundleURL.path];
 }
 
-#pragma mark Properties
+#pragma mark Installer State
 
-- (RACSignal *)getRequiredKey:(NSString *)key fromRequest:(SQRLShipItRequest *)request {
+- (RACSignal *)getRequiredKey:(NSString *)key fromState:(SQRLShipItState *)state {
 	NSParameterAssert(key != nil);
-	NSParameterAssert(request != nil);
+	NSParameterAssert(state != nil);
 
 	return [[RACSignal
 		defer:^{
-			id value = [request valueForKey:key];
+			id value = [state valueForKey:key];
 			if (value == nil) {
 				NSString *errorDescription = [NSString stringWithFormat:NSLocalizedString(@"Missing %@", nil), key];
 				return [RACSignal error:[self missingDataErrorWithDescription:errorDescription]];
@@ -210,210 +189,309 @@ NSString * const SQRLInstallerOwnedBundleKey = @"SQRLInstallerOwnedBundle";
 				return [RACSignal return:value];
 			}
 		}]
-		setNameWithFormat:@"%@ -getRequiredKey: %@ fromRequest: %@", self, key, request];
+		setNameWithFormat:@"%@ -getRequiredKey: %@ fromState: %@", self, key, state];
 }
 
-#pragma mark Installer States
+- (RACSignal *)resumeInstallationFromState:(SQRLShipItState *)state {
+	NSParameterAssert(state != nil);
 
-- (RACSignal *)prepareAndValidateUpdateBundleURLForRequest:(SQRLShipItRequest *)request {
-	NSParameterAssert(request != nil);
+	const SQRLInstallerDispatchTableEntry dispatchTablePrototype[] = {
+		{ .installerState = SQRLInstallerStateNothingToDo, .selector = NULL },
+		{ .installerState = SQRLInstallerStateClearingQuarantine, .selector = @selector(clearQuarantineWithState:) },
+		{ .installerState = SQRLInstallerStateBackingUp, .selector = @selector(backUpWithState:) },
+		{ .installerState = SQRLInstallerStateInstalling, .selector = @selector(installWithState:) },
+		{ .installerState = SQRLInstallerStateVerifyingInPlace, .selector = @selector(verifyInPlaceWithState:) },
+	};
 
-	return [[[[[[[self
-		ownedTemporaryDirectoryURL]
-		flattenMap:^(NSURL *directoryURL) {
-			return [self copyBundleAtURL:request.updateBundleURL toDirectory:directoryURL];
-		}]
+	const size_t tableCount = sizeof(dispatchTablePrototype) / sizeof(*dispatchTablePrototype);
+	NSValue *boxedDispatchTable = [NSValue valueWithBytes:dispatchTablePrototype objCType:@encode(__typeof__(dispatchTablePrototype))];
+
+	RACSignal *step = [RACSignal defer:^{
+		SQRLInstallerDispatchTableEntry dispatchTable[tableCount];
+		[boxedDispatchTable getValue:&dispatchTable];
+
+		SQRLInstallerState installerState = state.installerState;
+
+		size_t tableIndex;
+		for (tableIndex = 0; tableIndex < tableCount; tableIndex++) {
+			if (dispatchTable[tableIndex].installerState == installerState) {
+				break;
+			}
+		}
+
+		if (tableIndex >= tableCount) {
+			NSDictionary *userInfo = @{
+				NSLocalizedDescriptionKey: [NSString stringWithFormat:NSLocalizedString(@"Invalid installer state %i", nil), (int)installerState],
+				NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"Try installing the update again.", nil)
+			};
+
+			return [RACSignal error:[NSError errorWithDomain:SQRLInstallerErrorDomain code:SQRLInstallerErrorInvalidState userInfo:userInfo]];
+		}
+
+		SEL selector = dispatchTable[tableIndex].selector;
+		if (selector == NULL) {
+			// Nothing to do.
+			return [RACSignal empty];
+		}
+
+		NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:selector]];
+		invocation.target = self;
+		invocation.selector = selector;
+		
+		SQRLShipItState *stateArg = state;
+		[invocation setArgument:&stateArg atIndex:2];
+		[invocation invoke];
+
+		__unsafe_unretained RACSignal *step = nil;
+		[invocation getReturnValue:&step];
+
+		SQRLInstallerState nextState;
+		if (tableIndex + 1 >= tableCount) {
+			nextState = SQRLInstallerStateNothingToDo;
+		} else {
+			nextState = dispatchTable[tableIndex + 1].installerState;
+		}
+
+		return [[[step
+			doCompleted:^{
+				NSLog(@"Completed state %i", (int)installerState);
+			}]
+			ignoreValues]
+			concat:[RACSignal return:@(nextState)]];
+	}];
+
+	return [[self
+		stepRepeatedly:step withState:state]
+		setNameWithFormat:@"%@ -resumeInstallationFromState: %@", self, state];
+}
+
+- (RACSignal *)stepRepeatedly:(RACSignal *)step withState:(SQRLShipItState *)state {
+	NSParameterAssert(step != nil);
+	NSParameterAssert(state != nil);
+
+	return [step flattenMap:^(NSNumber *nextState) {
+		state.installerState = nextState.integerValue;
+		state.installationStateAttempt = 1;
+		return [[state
+			writeUsingURL:self.directoryManager.shipItStateURL]
+			// Automatically begin the next step.
+			concat:[self stepRepeatedly:step withState:state]];
+	}];
+}
+
+- (RACSignal *)clearQuarantineWithState:(SQRLShipItState *)state {
+	NSParameterAssert(state != nil);
+
+	return [[[self
+		getRequiredKey:@keypath(state.updateBundleURL) fromState:state]
 		flattenMap:^(NSURL *bundleURL) {
-			return [[[self
-				clearQuarantineForDirectory:bundleURL]
-				ignoreValues]
-				concat:[RACSignal return:bundleURL]];
+			return [self clearQuarantineForDirectory:bundleURL];
 		}]
-		zipWith:[self codeSignatureForBundleAtURL:request.targetBundleURL]]
-		reduceEach:^(NSURL *updateBundleURL, SQRLCodeSignature *codeSignature) {
-			return [[[self
-				verifyBundleAtURL:updateBundleURL usingSignature:codeSignature]
-				ignoreValues]
-				concat:[RACSignal return:updateBundleURL]];
-		}]
-		flatten]
-		setNameWithFormat:@"%@ -prepareAndValidateUpdateBundleURLForRequest: %@", self, request];
+		setNameWithFormat:@"%@ -clearQuarantineWithState: %@", self, state];
 }
 
-- (RACSignal *)acquireTargetBundleURLForRequest:(SQRLShipItRequest *)request {
-	NSParameterAssert(request != nil);
+- (RACSignal *)backUpWithState:(SQRLShipItState *)state {
+	NSParameterAssert(state != nil);
 
 	return [[[[RACSignal
 		zip:@[
-			[self ownedTemporaryDirectoryURL],
-			[self codeSignatureForBundleAtURL:request.targetBundleURL],
-		] reduce:^(NSURL *directoryURL, SQRLCodeSignature *codeSignature) {
-			NSURL *targetBundleURL = request.targetBundleURL;
-			NSURL *newBundleURL = [directoryURL URLByAppendingPathComponent:targetBundleURL.lastPathComponent];
+			[self getRequiredKey:@keypath(state.targetBundleURL) fromState:state],
+			[self getRequiredKey:@keypath(state.codeSignature) fromState:state],
+		] reduce:^(NSURL *bundleURL, SQRLCodeSignature *codeSignature) {
+			RACSignal *skipBackup = [RACSignal return:@NO];
+			if (state.backupBundleURL != nil) {
+				skipBackup = [self checkWhetherBundlePreviouslyAtURL:bundleURL wasInstalledAtURL:state.backupBundleURL usingSignature:codeSignature];
+			}
 
-			return [[SQRLInstallerOwnedBundle alloc] initWithOriginalURL:request.targetBundleURL temporaryURL:newBundleURL codeSignature:codeSignature];
+			return [skipBackup flattenMap:^(NSNumber *skip) {
+				if (skip.boolValue) {
+					return [RACSignal empty];
+				} else {
+					return [self backUpBundleAtURL:bundleURL];
+				}
+			}];
 		}]
-		doNext:^(SQRLInstallerOwnedBundle *ownedBundle) {
-			self.ownedBundle = ownedBundle;
+		flatten]
+		flattenMap:^(NSURL *backupBundleURL) {
+			// Save the chosen backup URL as soon as we have it, so we
+			// can resume even if the state change hasn't taken effect.
+			//
+			// N.B. It's important that this method remain
+			// synchronous, so it finishes before returning
+			// control to -backUpBundleAtURL:. Really, the flow
+			// here should be refactored so it doesn't matter.
+			state.backupBundleURL = backupBundleURL;
+			return [state writeUsingURL:self.directoryManager.shipItStateURL];
 		}]
-		flattenMap:^(SQRLInstallerOwnedBundle *ownedBundle) {
-			return [self installItemToURL:ownedBundle.temporaryURL fromURL:ownedBundle.originalURL];
-		}]
-		setNameWithFormat:@"%@ -acquireTargetBundleURLForRequest: %@", self, request];
+		setNameWithFormat:@"%@ -backUpWithState: %@", self, state];
 }
 
-- (RACSignal *)installRequest:(SQRLShipItRequest *)request {
-	NSParameterAssert(request != nil);
+- (RACSignal *)installWithState:(SQRLShipItState *)state {
+	NSParameterAssert(state != nil);
 
-	return [[[[self
-		prepareAndValidateUpdateBundleURLForRequest:request]
-		flattenMap:^(NSURL *updateBundleURL) {
-			return [[[[[[[self
-				acquireTargetBundleURLForRequest:request]
-				concat:[self installItemToURL:request.targetBundleURL fromURL:updateBundleURL]]
-				concat:[RACSignal return:request.updateBundleURL]]
-				concat:[RACSignal return:updateBundleURL]]
-				concat:[RACSignal defer:^{
-					return [RACSignal return:self.ownedBundle.temporaryURL];
-				}]]
-				flattenMap:^(NSURL *location) {
-					return [[[self
-						deleteOwnedBundleAtURL:location]
-						doError:^(NSError *error) {
-							NSLog(@"Couldn't remove owned bundle at location %@, error %@", location, error.sqrl_verboseDescription);
-						}]
-						catchTo:[RACSignal empty]];
+	return [[[RACSignal
+		zip:@[
+			[self getRequiredKey:@keypath(state.targetBundleURL) fromState:state],
+			[self getRequiredKey:@keypath(state.updateBundleURL) fromState:state],
+			[self getRequiredKey:@keypath(state.backupBundleURL) fromState:state],
+			[self getRequiredKey:@keypath(state.codeSignature) fromState:state]
+		] reduce:^(NSURL *targetBundleURL, NSURL *updateBundleURL, NSURL *backupBundleURL, SQRLCodeSignature *codeSignature) {
+			return [[[[self
+				checkWhetherBundlePreviouslyAtURL:updateBundleURL wasInstalledAtURL:targetBundleURL usingSignature:codeSignature]
+				flattenMap:^(NSNumber *skip) {
+					if (skip.boolValue) {
+						return [RACSignal empty];
+					} else {
+						return [self installItemAtURL:targetBundleURL fromURL:updateBundleURL];
+					}
 				}]
-				doCompleted:^{
-					self.ownedBundle = nil;
+				catch:^(NSError *error) {
+					NSString *description = [NSString stringWithFormat:NSLocalizedString(@"Failed to replace bundle %@ with update %@", nil), targetBundleURL, updateBundleURL];
+					return [RACSignal error:[self errorByAddingDescription:description code:SQRLInstallerErrorReplacingTarget toError:error]];
+				}]
+				catch:^(NSError *error) {
+					// Verify that the target bundle didn't get corrupted during
+					// failure. Try recovering it if it did.
+					return [[self
+						verifyBundleAtURL:targetBundleURL usingSignature:codeSignature recoveringUsingBackupAtURL:backupBundleURL]
+						// Recovery succeeded, but we still want to pass
+						// through the original error.
+						concat:[RACSignal error:error]];
 				}];
 		}]
-		sqrl_addTransactionWithName:NSLocalizedString(@"Updating", nil) description:NSLocalizedString(@"%@ is being updated, and interrupting the process could corrupt the application", nil), request.targetBundleURL.path]
-		setNameWithFormat:@"%@ -installRequest: %@", self, request];
+		flatten]
+		setNameWithFormat:@"%@ -installWithState: %@", self, state];
 }
 
-- (RACSignal *)abortInstall {
-	// The request may have been tampered with to select a new targetURL to
-	// which the moved bundles should be restored.
-	//
-	// Discard the request parameters and restore the owned bundle to its
-	// original location.
-
-	SQRLInstallerOwnedBundle *ownedBundle = self.ownedBundle;
-	if (ownedBundle == nil) return [RACSignal empty];
-
-	return [[[[self
-		installItemToURL:ownedBundle.originalURL fromURL:ownedBundle.temporaryURL]
-		doCompleted:^{
-			self.ownedBundle = nil;
-		}]
-		sqrl_addTransactionWithName:NSLocalizedString(@"Aborting update", nil) description:NSLocalizedString(@"An update to %@ is being rolled back, and interrupting the process could corrupt the application", nil), ownedBundle.originalURL.path]
-		setNameWithFormat:@"%@ -abortInstall", self];
-}
-
-#pragma mark Bundle Ownership
-
-- (RACSignal *)ownedTemporaryDirectoryURL {
-	return [[[RACSignal
-		defer:^{
-			NSString *tmpPath = [NSTemporaryDirectory() stringByResolvingSymlinksInPath];
-			NSString *template = [NSString stringWithFormat:@"%@.XXXXXXXX", self.applicationIdentifier];
-
-			char *fullTemplate = strdup([tmpPath stringByAppendingPathComponent:template].UTF8String);
-			@onExit {
-				free(fullTemplate);
-			};
-
-			if (mkdtemp(fullTemplate) == NULL) {
-				return [RACSignal error:[NSError errorWithDomain:NSPOSIXErrorDomain code:errno userInfo:nil]];
-			}
-
-			NSURL *URL = [NSURL fileURLWithPath:[NSFileManager.defaultManager stringWithFileSystemRepresentation:fullTemplate length:strlen(fullTemplate)] isDirectory:YES];
-			return [RACSignal return:URL];
-		}]
-		catch:^(NSError *error) {
-			NSString *description = [NSString stringWithFormat:NSLocalizedString(@"Could not create temporary folder", nil)];
-			return [RACSignal error:[self errorByAddingDescription:description code:SQRLInstallerErrorBackupFailed toError:error]];
-		}]
-		setNameWithFormat:@"%@ -ownedDirectoryURL", self];
-}
-
-- (RACSignal *)copyBundleAtURL:(NSURL *)bundleURL toDirectory:(NSURL *)directoryURL {
-	NSParameterAssert(bundleURL != nil);
-	NSParameterAssert(directoryURL != nil);
-
-	NSURL *newBundleURL = [directoryURL URLByAppendingPathComponent:bundleURL.lastPathComponent];
+- (RACSignal *)verifyInPlaceWithState:(SQRLShipItState *)state {
+	NSParameterAssert(state != nil);
 
 	return [[[RACSignal
-		defer:^{
-			NSError *error;
-			BOOL copy = [NSFileManager.defaultManager copyItemAtURL:bundleURL toURL:newBundleURL error:&error];
-			if (!copy) return [RACSignal error:error];
-
-			return [RACSignal return:newBundleURL];
+		zip:@[
+			[self getRequiredKey:@keypath(state.targetBundleURL) fromState:state],
+			[self getRequiredKey:@keypath(state.backupBundleURL) fromState:state],
+			[self getRequiredKey:@keypath(state.codeSignature) fromState:state]
+		] reduce:^(NSURL *targetBundleURL, NSURL *backupBundleURL, SQRLCodeSignature *codeSignature) {
+			return [[self
+				verifyBundleAtURL:targetBundleURL usingSignature:codeSignature recoveringUsingBackupAtURL:backupBundleURL]
+				concat:[[self
+					deleteBackupAtURL:backupBundleURL]
+					catchTo:[RACSignal empty]]];
 		}]
-		catch:^(NSError *error) {
-			NSString *description = [NSString stringWithFormat:NSLocalizedString(@"Failed to copy bundle %@ to directory %@", nil), bundleURL, newBundleURL];
-			return [RACSignal error:[self errorByAddingDescription:description code:SQRLInstallerErrorBackupFailed toError:error]];
-		}]
-		setNameWithFormat:@"%@ -copyBundleAtURL: %@ toDirectory: %@", self, bundleURL, directoryURL];
+		flatten]
+		setNameWithFormat:@"%@ -verifyInPlaceWithState: %@", self, state];
 }
 
-- (RACSignal *)deleteOwnedBundleAtURL:(NSURL *)bundleURL {
-	NSParameterAssert(bundleURL != nil);
+#pragma mark Backing Up
 
-	return [[[RACSignal
-		defer:^{
-			NSError *error;
-			if ([NSFileManager.defaultManager removeItemAtURL:bundleURL error:&error]) {
-				return [RACSignal empty];
-			} else {
+- (RACSignal *)backUpBundleAtURL:(NSURL *)targetBundleURL {
+	NSParameterAssert(targetBundleURL != nil);
+
+	return [[[[[[self.directoryManager
+		applicationSupportURL]
+		flattenMap:^(NSURL *applicationSupportURL) {
+			NSError *error = nil;
+			NSURL *temporaryDirectoryURL = [NSFileManager.defaultManager URLForDirectory:NSItemReplacementDirectory inDomain:NSUserDomainMask appropriateForURL:applicationSupportURL create:YES error:&error];
+			if (temporaryDirectoryURL == nil) {
 				return [RACSignal error:error];
 			}
+
+			return [RACSignal return:temporaryDirectoryURL];
 		}]
-		then:^{
+		catch:^(NSError *error) {
+			NSString *description = [NSString stringWithFormat:NSLocalizedString(@"Could not create backup folder", nil)];
+			return [RACSignal error:[self errorByAddingDescription:description code:SQRLInstallerErrorBackupFailed toError:error]];
+		}]
+		map:^(NSURL *temporaryDirectoryURL) {
+			return [temporaryDirectoryURL URLByAppendingPathComponent:targetBundleURL.lastPathComponent];
+		}]
+		flattenMap:^(NSURL *backupBundleURL) {
+			return [[[[self
+				installItemAtURL:backupBundleURL fromURL:targetBundleURL]
+				catch:^(NSError *error) {
+					NSString *description = [NSString stringWithFormat:NSLocalizedString(@"Failed to move bundle %@ to backup location %@", nil), targetBundleURL, backupBundleURL];
+					return [RACSignal error:[self errorByAddingDescription:description code:SQRLInstallerErrorBackupFailed toError:error]];
+				}]
+				ignoreValues]
+				// Return the backup URL before doing any work, to increase
+				// fault tolerance.
+				startWith:backupBundleURL];
+		}]
+		setNameWithFormat:@"%@ -backUpBundleAtURL: %@", self, targetBundleURL];
+}
+
+- (RACSignal *)deleteBackupAtURL:(NSURL *)backupURL {
+	NSParameterAssert(backupURL != nil);
+
+	return [[RACSignal
+		defer:^{
+			NSError *error = nil;
+			if (![NSFileManager.defaultManager removeItemAtURL:backupURL error:&error]) {
+				return [RACSignal error:error];
+			}
+
 			// Also remove the temporary directory that the backup lived in.
-			NSURL *temporaryDirectoryURL = bundleURL.URLByDeletingLastPathComponent;
+			NSURL *temporaryDirectoryURL = backupURL.URLByDeletingLastPathComponent;
 
 			// However, use rmdir() to skip it in case there are other files
 			// contained within (for whatever reason).
-			if (rmdir(temporaryDirectoryURL.path.fileSystemRepresentation) == 0) {
-				return [RACSignal empty];
-			} else {
+			if (rmdir(temporaryDirectoryURL.path.fileSystemRepresentation) != 0) {
 				return [RACSignal error:[NSError errorWithDomain:NSPOSIXErrorDomain code:errno userInfo:nil]];
 			}
+
+			return [RACSignal empty];
 		}]
-		setNameWithFormat:@"%@ -deleteOwnedBundleAtURL: %@", self, bundleURL];
+		setNameWithFormat:@"%@ -deleteBackupAtURL: %@", self, backupURL];
 }
 
-#pragma mark Verification
-
-- (RACSignal *)codeSignatureForBundleAtURL:(NSURL *)URL {
-	return [[RACSignal
-		defer:^{
-			NSError *error;
-			SQRLCodeSignature *codeSignature = [SQRLCodeSignature signatureWithBundle:URL error:&error];
-			if (codeSignature == nil) return [RACSignal error:error];
-			return [RACSignal return:codeSignature];
-		}]
-		setNameWithFormat:@"%@ -codeSignatureForBundleAtURL: %@", self, URL];
-}
-
-- (RACSignal *)verifyBundleAtURL:(NSURL *)bundleURL usingSignature:(SQRLCodeSignature *)signature {
+- (RACSignal *)verifyBundleAtURL:(NSURL *)bundleURL usingSignature:(SQRLCodeSignature *)signature recoveringUsingBackupAtURL:(NSURL *)backupBundleURL {
 	NSParameterAssert(bundleURL != nil);
 	NSParameterAssert(signature != nil);
 
-	return [[[self
-		takeOwnershipOfDirectory:bundleURL]
-		then:^{
-			return [signature verifyBundleAtURL:bundleURL];
+	return [[[signature
+		verifyBundleAtURL:bundleURL]
+		catch:^(NSError *error) {
+			if (backupBundleURL == nil) return [RACSignal error:error];
+
+			return [[[RACSignal
+				defer:^{
+					[NSFileManager.defaultManager removeItemAtURL:bundleURL error:NULL];
+
+					return [self installItemAtURL:bundleURL fromURL:backupBundleURL];
+				}]
+				doCompleted:^{
+					NSLog(@"Restored backup bundle to %@", bundleURL);
+				}]
+				doError:^(NSError *recoveryError) {
+					NSLog(@"Could not restore backup bundle %@ to %@: %@", backupBundleURL, bundleURL, recoveryError.sqrl_verboseDescription);
+				}];
 		}]
-		setNameWithFormat:@"%@ -verifyBundleAtURL: %@ usingSignature: %@", self, bundleURL, signature];
+		setNameWithFormat:@"%@ -verifyBundleAtURL: %@ usingSignature: %@ recoveringUsingBackupAtURL: %@", self, bundleURL, signature, backupBundleURL];
 }
 
 #pragma mark Installation
 
-- (RACSignal *)installItemToURL:(NSURL *)targetURL fromURL:(NSURL *)sourceURL {
+- (RACSignal *)checkWhetherBundlePreviouslyAtURL:(NSURL *)sourceURL wasInstalledAtURL:(NSURL *)targetURL usingSignature:(SQRLCodeSignature *)signature {
+	NSParameterAssert(targetURL != nil);
+	NSParameterAssert(sourceURL != nil);
+	NSParameterAssert(signature != nil);
+
+	return [[[[self
+		verifyBundleAtURL:targetURL usingSignature:signature recoveringUsingBackupAtURL:nil]
+		concat:[RACSignal return:@YES]]
+		catch:^(NSError *error) {
+			BOOL directory;
+			if ([NSFileManager.defaultManager fileExistsAtPath:sourceURL.path isDirectory:&directory]) {
+				// If the source still exists, this isn't an error.
+				return [RACSignal return:@NO];
+			} else {
+				return [RACSignal error:error];
+			}
+		}]
+		setNameWithFormat:@"%@ -checkWhetherBundlePreviouslyAtURL: %@ wasInstalledAtURL: %@", self, sourceURL, targetURL];
+}
+
+- (RACSignal *)installItemAtURL:(NSURL *)targetURL fromURL:(NSURL *)sourceURL {
 	NSParameterAssert(targetURL != nil);
 	NSParameterAssert(sourceURL != nil);
 
@@ -425,7 +503,7 @@ NSString * const SQRLInstallerOwnedBundleKey = @"SQRLInstallerOwnedBundle";
 			} else {
 				int code = errno;
 				NSMutableDictionary *userInfo = [NSMutableDictionary dictionary];
-
+				
 				const char *desc = strerror(code);
 				if (desc != NULL) userInfo[NSLocalizedDescriptionKey] = @(desc);
 
@@ -466,7 +544,7 @@ NSString * const SQRLInstallerOwnedBundleKey = @"SQRLInstallerOwnedBundle";
 				return YES;
 			}];
 
-			return enumerator.rac_sequence.signal;
+			return [enumerator.rac_promise start];
 		}]
 		flattenMap:^(NSURL *URL) {
 			const char *path = URL.path.fileSystemRepresentation;
@@ -477,7 +555,7 @@ NSString * const SQRLInstallerOwnedBundleKey = @"SQRLInstallerOwnedBundle";
 				// file to begin with.
 				if (code != ENOATTR) {
 					NSMutableDictionary *userInfo = [NSMutableDictionary dictionary];
-
+					
 					const char *desc = strerror(code);
 					if (desc != NULL) userInfo[NSLocalizedDescriptionKey] = @(desc);
 
@@ -490,97 +568,6 @@ NSString * const SQRLInstallerOwnedBundleKey = @"SQRLInstallerOwnedBundle";
 		setNameWithFormat:@"%@ -clearQuarantineForDirectory: %@", self, directory];
 }
 
-#pragma mark File Security
-
-- (RACSignal *)readFileSecurityOfURL:(NSURL *)location {
-	NSParameterAssert(location != nil);
-
-	return [[RACSignal
-		defer:^{
-			NSError *error;
-			NSFileSecurity *fileSecurity;
-			if (![location getResourceValue:&fileSecurity forKey:NSURLFileSecurityKey error:&error]) {
-				return [RACSignal error:error];
-			}
-
-			return [RACSignal return:fileSecurity];
-		}]
-		setNameWithFormat:@"%@ -readFileSecurity: %@", self, location];
-}
-
-- (RACSignal *)writeFileSecurity:(NSFileSecurity *)fileSecurity toURL:(NSURL *)location {
-	NSParameterAssert(location != nil);
-
-	return [[RACSignal
-		defer:^{
-			NSError *error;
-			if (![location setResourceValue:fileSecurity forKey:NSURLFileSecurityKey error:&error]) {
-				return [RACSignal error:error];
-			}
-
-			return [RACSignal empty];
-		}]
-		setNameWithFormat:@"%@ -writeFileSecurity: %@", self, location];
-}
-
-- (RACSignal *)takeOwnershipOfDirectory:(NSURL *)directoryURL {
-	NSParameterAssert(directoryURL != nil);
-
-	return [[[RACSignal
-		createSignal:^(id<RACSubscriber> subscriber) {
-			NSDirectoryEnumerator *enumerator = [NSFileManager.defaultManager enumeratorAtURL:directoryURL includingPropertiesForKeys:@[ NSURLFileSecurityKey ] options:0 errorHandler:^ BOOL (NSURL *url, NSError *error) {
-				[subscriber sendError:error];
-				return NO;
-			}];
-
-			return [[enumerator.rac_sequence.signal
-				startWith:directoryURL]
-				subscribe:subscriber];
-		}]
-		flattenMap:^(NSURL *itemURL) {
-			return [[[self
-				readFileSecurityOfURL:itemURL]
-				flattenMap:^(NSFileSecurity *fileSecurity) {
-					if (![self takeOwnershipOfFileSecurity:fileSecurity]) {
-						NSDictionary *errorInfo = @{
-							NSLocalizedDescriptionKey: NSLocalizedString(@"Permissions Error", nil),
-							NSLocalizedRecoverySuggestionErrorKey: [NSString stringWithFormat:NSLocalizedString(@"Couldn’t update permissions of %@", nil), itemURL.path],
-							NSURLErrorKey: itemURL
-						};
-
-						return [RACSignal error:[NSError errorWithDomain:SQRLInstallerErrorDomain code:SQRLInstallerErrorChangingPermissions userInfo:errorInfo]];
-					}
-
-					return [RACSignal return:fileSecurity];
-				}]
-				flattenMap:^(NSFileSecurity *fileSecurity) {
-					return [self writeFileSecurity:fileSecurity toURL:itemURL];
-				}];
-		}]
-		setNameWithFormat:@"%@ -takeOwnershipOfDirectory: %@", self, directoryURL];
-}
-
-- (BOOL)takeOwnershipOfFileSecurity:(NSFileSecurity *)fileSecurity {
-	CFFileSecurityRef actualFileSecurity = (__bridge CFFileSecurityRef)fileSecurity;
-
-	// If ShipIt is running as root, this will change the owner to
-	// root:wheel.
-	if (!CFFileSecuritySetOwner(actualFileSecurity, getuid())) return NO;
-	if (!CFFileSecuritySetGroup(actualFileSecurity, getgid())) return NO;
-
-	mode_t fileMode = 0;
-	if (!CFFileSecurityGetMode(actualFileSecurity, &fileMode)) return NO;
-
-	// Remove write permission from group and other, leave executable
-	// bit as it was for both.
-	//
-	// Permissions will be r-(x?)r-(x?) afterwards, with owner
-	// permissions left as is.
-	fileMode = (fileMode & ~(S_IWGRP | S_IWOTH));
-
-	return CFFileSecuritySetMode(actualFileSecurity, fileMode);
-}
-
 #pragma mark Error Handling
 
 - (NSError *)missingDataErrorWithDescription:(NSString *)description {

Squirrel/SQRLInstallerOwnedBundle.h

@@ -1,37 +0,0 @@
-//
-//  SQRLInstallerOwnedBundle.h
-//  Squirrel
-//
-//  Created by Keith Duncan on 08/01/2014.
-//  Copyright (c) 2014 GitHub. All rights reserved.
-//
-
-#import <Mantle/Mantle.h>
-
-@class SQRLCodeSignature;
-
-// Tracks original and temporary locations of a bundle. Should be created and
-// serialised before moving a bundle aside.
-//
-// Can be used to ensure new targetURL requests meet the original bundle at that
-// location's code signature, even though it's been moved aside.
-@interface SQRLInstallerOwnedBundle : MTLModel
-
-// Designated initialiser.
-//
-// originalURL   - Where the bundle currently resides, and should be restored to
-//                 should an error occur.
-// temporaryURL  - Where the bundle will be moved to, so that another bundle can
-//                 take its place at originalURL.
-// codeSignature - The code signature of the original bundle, so that the
-//                 signature can be used irrespective of where the bundle
-//                 currently resides.
-//
-// Returns an initialised owned bundle for serializing.
-- (instancetype)initWithOriginalURL:(NSURL *)originalURL temporaryURL:(NSURL *)temporaryURL codeSignature:(SQRLCodeSignature *)codeSignature;
-
-@property (readonly, copy, nonatomic) NSURL *originalURL;
-@property (readonly, copy, nonatomic) NSURL *temporaryURL;
-@property (readonly, copy, nonatomic) SQRLCodeSignature *codeSignature;
-
-@end

Squirrel/SQRLInstallerOwnedBundle.m

@@ -1,23 +0,0 @@
-//
-//  SQRLInstallerOwnedBundle.m
-//  Squirrel
-//
-//  Created by Keith Duncan on 08/01/2014.
-//  Copyright (c) 2014 GitHub. All rights reserved.
-//
-
-#import "SQRLInstallerOwnedBundle.h"
-
-#import "EXTKeyPathCoding.h"
-
-@implementation SQRLInstallerOwnedBundle
-
-- (instancetype)initWithOriginalURL:(NSURL *)originalURL temporaryURL:(NSURL *)temporaryURL codeSignature:(SQRLCodeSignature *)codeSignature {
-	return [self initWithDictionary:@{
-		@keypath(self.originalURL): originalURL,
-		@keypath(self.temporaryURL): temporaryURL,
-		@keypath(self.codeSignature): codeSignature,
-	} error:NULL];
-}
-
-@end

Squirrel/SQRLResumableDownload.h

@@ -0,0 +1,27 @@
+//
+//  SQRLResumableDownload.h
+//  Squirrel
+//
+//  Created by Keith Duncan on 30/09/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+#import "SQRLDownload.h"
+
+// A download which has already been started and already has partial data.
+@interface SQRLResumableDownload : SQRLDownload
+
+// Designated initialiser.
+//
+// request  - See `SQRLDownload`.
+// response - HTTP response whose body is being downloaded to `fileURL`.
+//            Must not be nil.
+// fileURL  - See `SQRLDownload`.
+- (instancetype)initWithRequest:(NSURLRequest *)request response:(NSHTTPURLResponse *)response fileURL:(NSURL *)fileURL;
+
+// The `response` the receiver was initialised with.
+@property (readonly, copy, nonatomic) NSHTTPURLResponse *response;
+
+@end

Squirrel/SQRLResumableDownload.m

@@ -0,0 +1,66 @@
+//
+//  SQRLResumableDownload.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 30/09/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "SQRLResumableDownload.h"
+
+#import <ReactiveCocoa/ReactiveCocoa.h>
+
+#import "NSHTTPURLResponse+SQRLExtensions.h"
+
+@implementation SQRLResumableDownload
+
+- (instancetype)initWithRequest:(NSURLRequest *)request response:(NSHTTPURLResponse *)response fileURL:(NSURL *)fileURL {
+	NSParameterAssert(request != nil);
+	NSParameterAssert(response != nil);
+	NSParameterAssert(fileURL != nil);
+
+	return [self initWithDictionary:@{
+		@keypath(self.request): request,
+		@keypath(self.response): response,
+		@keypath(self.fileURL): fileURL,
+	} error:NULL];
+}
+
+- (BOOL)isEqual:(SQRLResumableDownload *)object {
+	if (self == object) return YES;
+	if (![object isKindOfClass:self.class]) return NO;
+
+	if (!(self.response == nil && object.response == nil) && ![self responseEqual:object.response]) return NO;
+	if (![object.fileURL isEqual:self.fileURL]) return NO;
+
+	return YES;
+}
+
+- (BOOL)responseEqual:(NSHTTPURLResponse *)response {
+	if (![response.URL isEqual:self.response.URL]) return NO;
+	if (response.statusCode != self.response.statusCode) return NO;
+	if (![response.allHeaderFields isEqual:self.response.allHeaderFields]) return NO;
+	return YES;
+}
+
+- (RACSignal *)resumableRequest {
+	return [[[super
+		resumableRequest]
+		map:^ NSURLRequest * (NSURLRequest *request) {
+			NSHTTPURLResponse *response = self.response;
+			NSString *ETag = [response sqrl_valueForHTTPHeaderField:@"ETag"];
+			if (ETag == nil) return request;
+
+			NSNumber *alreadyDownloadedSize = nil;
+			BOOL getAlreadyDownloadedSize = [self.fileURL getResourceValue:&alreadyDownloadedSize forKey:NSURLFileSizeKey error:NULL];
+			if (!getAlreadyDownloadedSize) return request;
+
+			NSMutableURLRequest *newRequest = [request mutableCopy];
+			[newRequest setValue:ETag forHTTPHeaderField:@"If-Range"];
+			[newRequest setValue:[NSString stringWithFormat:@"%llu-", alreadyDownloadedSize.unsignedLongLongValue] forHTTPHeaderField:@"Range"];
+			return newRequest;
+		}]
+		setNameWithFormat:@"%@ %s", self, sel_getName(_cmd)];
+}
+
+@end

Squirrel/SQRLShipItLauncher.m

@@ -13,7 +13,6 @@
 #import <Security/Security.h>
 #import <ServiceManagement/ServiceManagement.h>
 #import <launch.h>
-#import "SQRLAuthorization.h"
 
 NSString * const SQRLShipItLauncherErrorDomain = @"SQRLShipItLauncherErrorDomain";
 
@@ -22,7 +21,8 @@ const NSInteger SQRLShipItLauncherErrorCouldNotStartService = 1;
 @implementation SQRLShipItLauncher
 
 + (NSString *)shipItJobLabel {
-	return [SQRLDirectoryManager.currentApplicationManager.applicationIdentifier stringByAppendingString:@".ShipIt"];
+	NSString *currentAppIdentifier = NSBundle.mainBundle.bundleIdentifier ?: [NSString stringWithFormat:@"%@:%d", NSProcessInfo.processInfo.processName, NSProcessInfo.processInfo.processIdentifier];
+	return [currentAppIdentifier stringByAppendingString:@".ShipIt"];
 }
 
 + (RACSignal *)shipItJobDictionary {
@@ -60,6 +60,10 @@ const NSInteger SQRLShipItLauncherErrorCouldNotStartService = 1;
 			jobDict[@(LAUNCH_JOBKEY_STANDARDOUTPATH)] = [appSupportURL URLByAppendingPathComponent:@"ShipIt_stdout.log"].path;
 			jobDict[@(LAUNCH_JOBKEY_STANDARDERRORPATH)] = [appSupportURL URLByAppendingPathComponent:@"ShipIt_stderr.log"].path;
 
+			#if DEBUG
+			jobDict[@(LAUNCH_JOBKEY_DEBUG)] = @YES;
+			#endif
+			
 			return jobDict;
 		}]
 		setNameWithFormat:@"+shipItJobDictionary"];
@@ -67,7 +71,7 @@ const NSInteger SQRLShipItLauncherErrorCouldNotStartService = 1;
 
 + (RACSignal *)shipItAuthorization {
 	return [[RACSignal
-		createSignal:^ RACDisposable * (id<RACSubscriber> subscriber) {
+		create:^(id<RACSubscriber> subscriber) {
 			AuthorizationItem rightItems[] = {
 				{
 					.name = kSMRightModifySystemDaemons,
@@ -104,15 +108,16 @@ const NSInteger SQRLShipItLauncherErrorCouldNotStartService = 1;
 
 			AuthorizationRef authorization = NULL;
 			OSStatus authorizationError = AuthorizationCreate(&rights, &environment, kAuthorizationFlagInteractionAllowed | kAuthorizationFlagExtendRights, &authorization);
-
 			if (authorizationError == noErr) {
-				[subscriber sendNext:[[SQRLAuthorization alloc] initWithAuthorization:authorization]];
+				[subscriber sendNext:(__bridge id)authorization];
 				[subscriber sendCompleted];
 			} else {
 				[subscriber sendError:[NSError errorWithDomain:NSOSStatusErrorDomain code:authorizationError userInfo:nil]];
 			}
 
-			return nil;
+			[subscriber.disposable addDisposable:[RACDisposable disposableWithBlock:^{
+				if (authorization != NULL) AuthorizationFree(authorization, kAuthorizationFlagDestroyRights);
+			}]];
 		}]
 		setNameWithFormat:@"+shipItAuthorization"];
 }
@@ -122,13 +127,11 @@ const NSInteger SQRLShipItLauncherErrorCouldNotStartService = 1;
 		zip:@[
 			self.shipItJobDictionary,
 			(privileged ? self.shipItAuthorization : [RACSignal return:nil])
-		] reduce:^(NSDictionary *jobDictionary, SQRLAuthorization *authorizationValue) {
+		] reduce:^(NSDictionary *jobDictionary, id authorization) {
 			CFStringRef domain = (privileged ? kSMDomainSystemLaunchd : kSMDomainUserLaunchd);
 
-			AuthorizationRef authorization = authorizationValue.authorization;
-
 			CFErrorRef cfError;
-			if (!SMJobRemove(domain, (__bridge CFStringRef)self.shipItJobLabel, authorization, true, &cfError)) {
+			if (!SMJobRemove(domain, (__bridge CFStringRef)self.shipItJobLabel, (__bridge AuthorizationRef)authorization, true, &cfError)) {
 				NSError *error = CFBridgingRelease(cfError);
 				cfError = NULL;
 
@@ -137,7 +140,7 @@ const NSInteger SQRLShipItLauncherErrorCouldNotStartService = 1;
 				}
 			}
 
-			if (!SMJobSubmit(domain, (__bridge CFDictionaryRef)jobDictionary, authorization, &cfError)) {
+			if (!SMJobSubmit(domain, (__bridge CFDictionaryRef)jobDictionary, (__bridge AuthorizationRef)authorization, &cfError)) {
 				return [RACSignal error:CFBridgingRelease(cfError)];
 			}
 

Squirrel/SQRLShipItRequest.h

@@ -1,96 +0,0 @@
-//
-//  SQRLShipItRequest.h
-//  Squirrel
-//
-//  Created by Keith Duncan on 08/01/2014.
-//  Copyright (c) 2014 GitHub. All rights reserved.
-//
-
-#import <Mantle/Mantle.h>
-
-@class RACSignal;
-
-// The domain for errors originating within `SQRLShipItRequest`.
-extern NSString * const SQRLShipItRequestErrorDomain;
-
-// Errors originating from the `SQRLShipItRequestErrorDomain`.
-//
-// SQRLShipItRequestErrorMissingRequiredProperty - A required property was `nil`
-//                                                 upon initialization.
-//
-//                                                 The `userInfo` dictionary for
-//                                                 this error will contain
-//                                                 `SQRLShipItStatePropertyErrorKey`.
-//
-// SQRLShipItRequestErrorUnarchiving             - The saved request could not
-//                                                 be unarchived, possibly
-//                                                 because it's invalid.
-//
-// SQRLShipItRequestErrorArchiving               - The request object could not
-//                                                 be archived.
-typedef enum : NSInteger {
-	SQRLShipItRequestErrorMissingRequiredProperty = 1,
-	SQRLShipItRequestErrorUnarchiving = 2,
-	SQRLShipItRequestErrorArchiving = 3,
-} SQRLShipItRequestError;
-
-// Associated with an `NSString` indicating the required property key that did
-// not have a value upon initialization.
-extern NSString * const SQRLShipItRequestPropertyErrorKey;
-
-// Constructed and written to disk for `ShipIt` to pick up. This represents a
-// single update request from the client's perspective.
-@interface SQRLShipItRequest : MTLModel
-
-// Reads a `SQRLShipItState` from disk, at the location specified by the given
-// URL signal.
-//
-// URLSignal - Determines the file location to read from, the signal should send
-//             an `NSURL` object then complete, or error. This must not be nil.
-//
-// Returns a signal which will synchronously send a `SQRLShipItRequest` then
-// complete, or error.
-+ (RACSignal *)readUsingURL:(RACSignal *)URLSignal;
-
-// Writes the receiver to disk, at the location specified by the given URL
-// signal.
-//
-// URLSignal - Determines the file location to write to. The signal should send
-//             an `NSURL` object then complete, or error. This must not be nil.
-//
-// Returns a signal which will synchronously complete or error.
-- (RACSignal *)writeUsingURL:(RACSignal *)URLSignal;
-
-// Designated initialiser.
-//
-// updateBundleURL         - The update bundle which will replace
-//                           targetBundleURL. Must not be nil.
-// targetBundleURL         - Where the update should be installed, if a bundle
-//                           is already present, the update is checked for
-//                           suitability against this bundle. Must not be nil.
-// bundleIdentifier        - The bundle identifier that the installer should
-//                           wait for instances of to terminate before
-//                           installing. Can be nil.
-// launchAfterInstallation - Whether the updated application should be launched
-//                           after installation.
-//
-// Returns a request which can be written to disk for ShipIt to read and
-// perform.
-- (instancetype)initWithUpdateBundleURL:(NSURL *)updateBundleURL targetBundleURL:(NSURL *)targetBundleURL bundleIdentifier:(NSString *)bundleIdentifier launchAfterInstallation:(BOOL)launchAfterInstallation;
-
-// The URL to the downloaded update's app bundle.
-@property (nonatomic, copy, readonly) NSURL *updateBundleURL;
-
-// The URL to the app bundle that should be replaced with the update.
-@property (nonatomic, copy, readonly) NSURL *targetBundleURL;
-
-// The bundle identifier of the application being updated.
-//
-// If not nil, the installer will wait for applications matching this identifier
-// (and `targetBundleURL`) to terminate before continuing.
-@property (nonatomic, copy, readonly) NSString *bundleIdentifier;
-
-// Whether to launch the application after an update is successfully installed.
-@property (nonatomic, assign, readonly) BOOL launchAfterInstallation;
-
-@end

Squirrel/SQRLShipItRequest.m

@@ -1,193 +0,0 @@
-//
-//  SQRLShipItRequest.m
-//  Squirrel
-//
-//  Created by Keith Duncan on 08/01/2014.
-//  Copyright (c) 2014 GitHub. All rights reserved.
-//
-
-#import "SQRLShipItRequest.h"
-
-#import "EXTKeyPathCoding.h"
-#import <ReactiveCocoa/RACSignal+Operations.h>
-
-NSString * const SQRLShipItRequestErrorDomain = @"SQRLShipItRequestErrorDomain";
-
-NSString * const SQRLShipItRequestPropertyErrorKey = @"SQRLShipItRequestPropertyErrorKey";
-
-@interface SQRLShipItRequest () <MTLJSONSerializing>
-@end
-
-@implementation SQRLShipItRequest
-
-#pragma mark Lifecycle
-
-- (id)initWithDictionary:(NSDictionary *)dictionary error:(NSError **)error {
-	self = [super initWithDictionary:dictionary error:error];
-	if (self == nil) return nil;
-
-	BOOL (^validateKey)(NSString *) = ^(NSString *key) {
-		if ([self valueForKey:key] != nil) return YES;
-
-		if (error != NULL) {
-			NSDictionary *userInfo = @{
-				NSLocalizedDescriptionKey: NSLocalizedString(@"Missing required value", nil),
-				NSLocalizedRecoverySuggestionErrorKey: [NSString stringWithFormat:NSLocalizedString(@"\"%@\" must not be set to nil.", nil), key]
-			};
-
-			*error = [NSError errorWithDomain:SQRLShipItRequestErrorDomain code:SQRLShipItRequestErrorMissingRequiredProperty userInfo:userInfo];
-		}
-
-		return NO;
-	};
-
-	if (!validateKey(@keypath(self.targetBundleURL))) return nil;
-	if (!validateKey(@keypath(self.updateBundleURL))) return nil;
-
-	return self;
-}
-
-- (instancetype)initWithUpdateBundleURL:(NSURL *)updateBundleURL targetBundleURL:(NSURL *)targetBundleURL bundleIdentifier:(NSString *)bundleIdentifier launchAfterInstallation:(BOOL)launchAfterInstallation {
-	return [self initWithDictionary:@{
-		@keypath(self.updateBundleURL): updateBundleURL,
-		@keypath(self.targetBundleURL): targetBundleURL,
-		@keypath(self.bundleIdentifier): bundleIdentifier ?: NSNull.null,
-		@keypath(self.launchAfterInstallation): @(launchAfterInstallation),
-	} error:NULL];
-}
-
-#pragma mark Serialization
-
-+ (NSDictionary *)JSONKeyPathsByPropertyKey {
-	return @{};
-}
-
-+ (NSValueTransformer *)updateBundleURLJSONTransformer {
-	return [NSValueTransformer valueTransformerForName:MTLURLValueTransformerName];
-}
-
-+ (NSValueTransformer *)targetBundleURLJSONTransformer {
-	return [NSValueTransformer valueTransformerForName:MTLURLValueTransformerName];
-}
-
-+ (RACSignal *)readUsingURL:(RACSignal *)URL {
-	NSParameterAssert(URL != nil);
-
-	return [[[[URL
-		flattenMap:^(NSURL *stateURL) {
-			NSError *error;
-			NSData *data = [self readFromURL:stateURL error:&error];
-			if (data == nil) {
-				return [RACSignal error:error];
-			}
-
-			return [RACSignal return:data];
-		}]
-		flattenMap:^(NSData *data) {
-			return [self readFromData:data];
-		}]
-		catch:^(NSError *error) {
-			NSDictionary *userInfo = @{
-				NSLocalizedDescriptionKey: NSLocalizedString(@"Could not read update request", nil),
-			};
-			if (error != nil) {
-				userInfo = [userInfo mtl_dictionaryByAddingEntriesFromDictionary:@{
-					NSUnderlyingErrorKey: error,
-				}];
-			}
-			return [RACSignal error:[NSError errorWithDomain:SQRLShipItRequestErrorDomain code:SQRLShipItRequestErrorUnarchiving userInfo:userInfo]];
-		}]
-		setNameWithFormat:@"+readUsingURL: %@", URL];
-}
-
-+ (NSData *)readFromURL:(NSURL *)URL error:(NSError **)errorRef {
-	__block NSData *data = nil;
-
-	NSFileCoordinator *coordinator = [[NSFileCoordinator alloc] initWithFilePresenter:nil];
-	[coordinator coordinateReadingItemAtURL:URL options:NSFileCoordinatorReadingWithoutChanges error:errorRef byAccessor:^(NSURL *newURL) {
-		data = [NSData dataWithContentsOfURL:newURL options:NSDataReadingUncached error:errorRef];
-	}];
-
-	return data;
-}
-
-+ (RACSignal *)readFromData:(NSData *)data {
-	return [[RACSignal
-		defer:^{
-			NSError *error;
-			NSDictionary *JSONDictionary = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
-			if (JSONDictionary == nil) {
-				return [RACSignal error:error];
-			}
-
-			SQRLShipItRequest *request = [MTLJSONAdapter modelOfClass:SQRLShipItRequest.class fromJSONDictionary:JSONDictionary error:&error];
-			if (request == nil) {
-				return [RACSignal error:error];
-			}
-
-			return [RACSignal return:request];
-
-		}]
-		setNameWithFormat:@"+readFromData: <NSData %p>", data];
-}
-
-- (RACSignal *)writeUsingURL:(RACSignal *)URL {
-	NSParameterAssert(URL != nil);
-
-	return [[[[RACSignal
-		zip:@[
-			URL,
-			[self serialization]
-		] reduce:^(NSURL *stateURL, NSData *data) {
-			NSError *error;
-			BOOL write = [self writeData:data toURL:stateURL error:&error];
-			if (!write) {
-				return [RACSignal error:error];
-			}
-
-			return [RACSignal empty];
-		}]
-		flatten]
-		catch:^(NSError *error) {
-			NSDictionary *userInfo = @{
-				NSLocalizedDescriptionKey: NSLocalizedString(@"Could not write update request", nil),
-				NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"An unknown error occurred while archiving.", nil),
-			};
-			if (error != nil) {
-				userInfo = [userInfo mtl_dictionaryByAddingEntriesFromDictionary:@{
-					NSUnderlyingErrorKey: error,
-				}];
-			}
-			return [RACSignal error:[NSError errorWithDomain:SQRLShipItRequestErrorDomain code:SQRLShipItRequestErrorArchiving userInfo:userInfo]];
-		}]
-		setNameWithFormat:@"%@ -writeUsingURL: %@", self, URL];
-}
-
-- (BOOL)writeData:(NSData *)data toURL:(NSURL *)URL error:(NSError **)errorRef {
-	__block BOOL success = NO;
-
-	NSFileCoordinator *coordinator = [[NSFileCoordinator alloc] initWithFilePresenter:nil];
-	[coordinator coordinateWritingItemAtURL:URL options:0 error:errorRef byAccessor:^(NSURL *newURL) {
-		success = [data writeToURL:newURL options:NSDataWritingAtomic error:errorRef];
-	}];
-
-	return success;
-}
-
-- (RACSignal *)serialization {
-	return [[RACSignal
-		defer:^{
-			NSDictionary *JSONDictionary = [MTLJSONAdapter JSONDictionaryFromModel:self];
-
-			NSError *error;
-			NSData *data = [NSJSONSerialization dataWithJSONObject:JSONDictionary options:0 error:&error];
-			if (data == nil) {
-				return [RACSignal error:error];
-			}
-
-			return [RACSignal return:data];
-		}]
-		setNameWithFormat:@"%@ serialization", self];
-}
-
-@end

Squirrel/SQRLShipItState.h

@@ -0,0 +1,117 @@
+//
+//  SQRLShipItState.h
+//  Squirrel
+//
+//  Created by Justin Spahr-Summers on 2013-10-08.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import <Mantle/Mantle.h>
+
+// The domain for errors originating within `SQRLShipItState`.
+extern NSString * const SQRLShipItStateErrorDomain;
+
+// A required property was `nil` upon initialization.
+//
+// The `userInfo` dictionary for this error will contain
+// `SQRLShipItStatePropertyErrorKey`.
+extern const NSInteger SQRLShipItStateErrorMissingRequiredProperty;
+
+// The saved state on disk could not be unarchived, possibly because it's
+// invalid.
+extern const NSInteger SQRLShipItStateErrorUnarchiving;
+
+// The state object could not be archived.
+extern const NSInteger SQRLShipItStateErrorArchiving;
+
+// Associated with an NSString indicating the required property key that did not
+// have a value upon initialization.
+extern NSString * const SQRLShipItStatePropertyErrorKey;
+
+// The current state of the installer, for persistence across relaunches and for
+// tolerance of system failures.
+//
+// SQRLInstallerStateNothingToDo        - ShipIt has not started installing yet.
+// SQRLInstallerStateClearingQuarantine - Clearing the quarantine flag on the
+//                                        update bundle so it can used without
+//                                        issue.
+// SQRLInstallerStateBackingUp          - Backing up the target bundle so it can
+//                                        be restored in the event of failure.
+// SQRLInstallerStateInstalling         - Replacing the target bundle with the
+//                                        update bundle.
+// SQRLInstallerStateVerifyingInPlace   - Verifying that the target bundle is
+//                                        still valid after updating.
+//
+// Note that these values must remain backwards compatible, so ShipIt doesn't
+// start up in a weird mode on a newer version.
+typedef enum : NSInteger {
+	SQRLInstallerStateNothingToDo = 0,
+	SQRLInstallerStateClearingQuarantine,
+	SQRLInstallerStateBackingUp,
+	SQRLInstallerStateInstalling,
+	SQRLInstallerStateVerifyingInPlace,
+} SQRLInstallerState;
+
+@class RACSignal;
+@class SQRLCodeSignature;
+
+// Encapsulates all the state needed by the ShipIt process.
+@interface SQRLShipItState : MTLModel
+
+// Reads a `SQRLShipItState` from disk, at the location specified by the given
+// URL signal.
+//
+// URLSignal - Determines the file location to read from, the signal should send
+//             an `NSURL` object then complete, or error. This must not be nil.
+//
+// Returns a signal which will synchronously send a `SQRLShipItState` then
+// complete, or error.
++ (RACSignal *)readUsingURL:(RACSignal *)URL;
+
+// Initializes the receiver with the arguments that will not change during
+// installation.
+- (id)initWithTargetBundleURL:(NSURL *)targetBundleURL updateBundleURL:(NSURL *)updateBundleURL bundleIdentifier:(NSString *)bundleIdentifier codeSignature:(SQRLCodeSignature *)codeSignature;
+
+// Writes the receiver to disk, at the location specified by the given URL
+// signal.
+//
+// URL - Determines the file location to write to. The signal should send an
+//       `NSURL` object then complete, or error. This must not be nil.
+//
+// Returns a signal which will synchronously complete or error.
+- (RACSignal *)writeUsingURL:(RACSignal *)URL;
+
+// The URL to the app bundle that should be replaced with an update.
+@property (nonatomic, copy, readonly) NSURL *targetBundleURL;
+
+// The URL to the downloaded update's app bundle.
+@property (nonatomic, copy, readonly) NSURL *updateBundleURL;
+
+// A code signature that the update bundle must match in order to be valid.
+@property (nonatomic, copy, readonly) SQRLCodeSignature *codeSignature;
+
+// The bundle identifier of the application being updated.
+//
+// If not nil, the installer will wait for applications matching this identifier
+// (and `targetBundleURL`) to terminate before continuing.
+@property (nonatomic, copy, readonly) NSString *bundleIdentifier;
+
+// The current state of the installer.
+@property (atomic, assign) SQRLInstallerState installerState;
+
+// The number of installation attempts that have occurred for the current
+// `state`.
+@property (atomic, assign) NSUInteger installationStateAttempt;
+
+// Whether to relaunch the application after an update is successfully
+// installed.
+@property (atomic, assign) BOOL relaunchAfterInstallation;
+
+// The URL where the target bundle has been backed up to before installing the
+// update.
+//
+// This property is set automatically during the course of installation. It
+// should not be preset.
+@property (atomic, copy) NSURL *backupBundleURL;
+
+@end

Squirrel/SQRLShipItState.m

@@ -0,0 +1,122 @@
+//
+//  SQRLShipItState.m
+//  Squirrel
+//
+//  Created by Justin Spahr-Summers on 2013-10-08.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "SQRLShipItState.h"
+#import <ReactiveCocoa/ReactiveCocoa.h>
+
+NSString * const SQRLShipItStateErrorDomain = @"SQRLShipItStateErrorDomain";
+NSString * const SQRLShipItStatePropertyErrorKey = @"SQRLShipItStatePropertyErrorKey";
+
+const NSInteger SQRLShipItStateErrorMissingRequiredProperty = 1;
+const NSInteger SQRLShipItStateErrorUnarchiving = 2;
+const NSInteger SQRLShipItStateErrorArchiving = 3;
+
+@implementation SQRLShipItState
+
+#pragma mark Lifecycle
+
+- (id)initWithDictionary:(NSDictionary *)dictionary error:(NSError **)error {
+	self = [super initWithDictionary:dictionary error:error];
+	if (self == nil) return nil;
+
+	BOOL (^validateKey)(NSString *) = ^(NSString *key) {
+		if ([self valueForKey:key] != nil) return YES;
+
+		if (error != NULL) {
+			NSDictionary *userInfo = @{
+				NSLocalizedDescriptionKey: NSLocalizedString(@"Missing required value", nil),
+				NSLocalizedRecoverySuggestionErrorKey: [NSString stringWithFormat:NSLocalizedString(@"\"%@\" must not be set to nil.", nil), key]
+			};
+
+			*error = [NSError errorWithDomain:SQRLShipItStateErrorDomain code:SQRLShipItStateErrorMissingRequiredProperty userInfo:userInfo];
+		}
+
+		return NO;
+	};
+
+	if (!validateKey(@keypath(self.targetBundleURL))) return nil;
+	if (!validateKey(@keypath(self.updateBundleURL))) return nil;
+	if (!validateKey(@keypath(self.codeSignature))) return nil;
+
+	return self;
+}
+
+- (id)initWithTargetBundleURL:(NSURL *)targetBundleURL updateBundleURL:(NSURL *)updateBundleURL bundleIdentifier:(NSString *)bundleIdentifier codeSignature:(SQRLCodeSignature *)codeSignature {
+	return [self initWithDictionary:@{
+		@keypath(self.targetBundleURL): targetBundleURL,
+		@keypath(self.updateBundleURL): updateBundleURL,
+		@keypath(self.bundleIdentifier): bundleIdentifier ?: NSNull.null,
+		@keypath(self.codeSignature): codeSignature,
+	} error:NULL];
+}
+
+#pragma mark Serialization
+
++ (RACSignal *)readUsingURL:(RACSignal *)URL {
+	NSParameterAssert(URL != nil);
+
+	return [[[URL
+		flattenMap:^(NSURL *stateURL) {
+			NSError *error = nil;
+			NSData *data = [NSData dataWithContentsOfURL:stateURL options:NSDataReadingUncached error:&error];
+			if (data == nil) {
+				return [RACSignal error:error];
+			}
+
+			return [RACSignal return:data];
+		}]
+		flattenMap:^(NSData *data) {
+			SQRLShipItState *state = [NSKeyedUnarchiver unarchiveObjectWithData:data];
+			if (![state isKindOfClass:SQRLShipItState.class]) {
+				NSDictionary *userInfo = @{
+					NSLocalizedDescriptionKey: NSLocalizedString(@"Could not read saved state", nil),
+					NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"An unknown error occurred while unarchiving.", nil)
+				};
+
+				return [RACSignal error:[NSError errorWithDomain:SQRLShipItStateErrorDomain code:SQRLShipItStateErrorUnarchiving userInfo:userInfo]];
+			}
+
+			return [RACSignal return:state];
+		}]
+		setNameWithFormat:@"+readUsingURL: %@", URL];
+}
+
+- (RACSignal *)writeUsingURL:(RACSignal *)URL {
+	NSParameterAssert(URL != nil);
+
+	RACSignal *serialization = [RACSignal defer:^{
+		NSData *data = [NSKeyedArchiver archivedDataWithRootObject:self];
+		if (data == nil) {
+			NSDictionary *userInfo = @{
+				NSLocalizedDescriptionKey: NSLocalizedString(@"Could not save state", nil),
+				NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"An unknown error occurred while archiving.", nil)
+			};
+
+			return [RACSignal error:[NSError errorWithDomain:SQRLShipItStateErrorDomain code:SQRLShipItStateErrorArchiving userInfo:userInfo]];
+		}
+
+		return [RACSignal return:data];
+	}];
+
+	return [[[RACSignal
+		zip:@[
+			URL,
+			serialization
+		] reduce:^(NSURL *stateURL, NSData *data) {
+			NSError *error = nil;
+			if (![data writeToURL:stateURL options:NSDataWritingAtomic error:&error]) {
+				return [RACSignal error:error];
+			}
+
+			return [RACSignal empty];
+		}]
+		flatten]
+		setNameWithFormat:@"%@ -writeUsingURL: %@", self, URL];
+}
+
+@end

Squirrel/SQRLTerminationListener.h

@@ -6,7 +6,7 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Cocoa/Cocoa.h>
+#import <Foundation/Foundation.h>
 
 @class RACSignal;
 

Squirrel/SQRLTerminationListener.m

@@ -7,14 +7,7 @@
 //
 
 #import "SQRLTerminationListener.h"
-
-#import "EXTKeyPathCoding.h"
-#import <ReactiveCocoa/NSArray+RACSequenceAdditions.h>
-#import <ReactiveCocoa/RACDisposable.h>
-#import <ReactiveCocoa/RACScheduler.h>
-#import <ReactiveCocoa/RACSequence.h>
-#import <ReactiveCocoa/RACSignal+Operations.h>
-#import <ReactiveCocoa/RACSubscriber.h>
+#import <ReactiveCocoa/ReactiveCocoa.h>
 
 @interface SQRLTerminationListener ()
 
@@ -52,7 +45,7 @@
 	return [[[[RACSignal
 		defer:^{
 			NSArray *apps = [NSRunningApplication runningApplicationsWithBundleIdentifier:self.bundleIdentifier];
-			return [apps.rac_sequence signalWithScheduler:RACScheduler.immediateScheduler];
+			return apps.rac_signal;
 		}]
 		filter:^(NSRunningApplication *application) {
 			return [application.bundleURL.URLByStandardizingPath isEqual:self.bundleURL];
@@ -67,7 +60,7 @@
 
 - (RACSignal *)waitForTerminationOfProcessIdentifier:(pid_t)processIdentifier {
 	return [[RACSignal
-		createSignal:^(id<RACSubscriber> subscriber) {
+		create:^(id<RACSubscriber> subscriber) {
 			dispatch_source_t source = dispatch_source_create(DISPATCH_SOURCE_TYPE_PROC, processIdentifier, DISPATCH_PROC_EXIT, dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0));
 
 			dispatch_source_set_registration_handler(source, ^{
@@ -79,9 +72,10 @@
 			});
 
 			dispatch_resume(source);
-			return [RACDisposable disposableWithBlock:^{
+			[subscriber.disposable addDisposable:[RACDisposable disposableWithBlock:^{
 				dispatch_source_cancel(source);
-			}];
+				dispatch_release(source);
+			}]];
 		}]
 		setNameWithFormat:@"%@ -waitForTerminationOfProcessIdentifier: %i", self, (int)processIdentifier];
 }

Squirrel/SQRLURLConnection.h

@@ -0,0 +1,49 @@
+//
+//  SQRLURLConnection.h
+//  Squirrel
+//
+//  Created by Keith Duncan on 25/09/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@class SQRLDownloadManager;
+@class RACSignal;
+
+// Resumably download a remote resource.
+//
+// If the resource has previously been downloaded this operation may return the
+// URL of an existing file, contingent on the server matching the ETag of the
+// original response.
+@interface SQRLURLConnection : NSObject
+
+// This is the designated initialiser. The body of the response is streamed to
+// disk. If the response includes an ETag the download can be resumed
+// automatically by subsequent download operations initialised with a request of
+// equal URL.
+//
+// request - Must not be nil, the request is issued with NSURLConnection.
+- (instancetype)initWithRequest:(NSURLRequest *)request __attribute__((nonnull (1)));
+
+// Starts accumulating the resource body in memory, cancels when the
+// subscription is disposed.
+//
+// Returns a signal when sends a tuple of `NSURLResponse` and `NSData`, then
+// completes or errors.
+- (RACSignal *)retrieve;
+
+// Starts downloading the resource body to disk, resuming from a previous
+// download if possible, cancels when the subscription is disposed.
+//
+// downloadManager - Must be non nil, determines where the downloads will be
+//                   stored and resumed from. For a previously started download
+//                   to be resumed, an equivalent download manager should be
+//                   provided.
+//
+// Returns a signal which sends a tuple of `NSURLResponse` and a file
+// scheme `NSURL` where the resource has been stored on disk, then completes, or
+// errors.
+- (RACSignal *)download:(SQRLDownloadManager *)downloadManager __attribute__((nonnull (1)));
+
+@end

Squirrel/SQRLURLConnection.m

@@ -0,0 +1,257 @@
+//
+//  SQRLURLConnection.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 25/09/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "SQRLURLConnection.h"
+
+#import <ReactiveCocoa/ReactiveCocoa.h>
+#import <ReactiveCocoa/EXTScope.h>
+
+#import "SQRLDownloadManager.h"
+#import "SQRLResumableDownload.h"
+
+@interface SQRLURLConnection ()
+// The request the downloader was initialised with.
+@property (nonatomic, copy, readonly) NSURLRequest *request;
+
+// Listens for invocations of `selector` on the receiver.
+//
+// The first argument of `selector` must be an `NSURLConnection` object.
+//
+// Returns a signal which sends the _second_ argument of `selector`, or
+// RACUnit if there is only one argument, then completes when the receiver
+// deallocates.
+- (RACSignal *)signalForDelegateSelector:(SEL)selector;
+
+// Subscribes to the connection delegate selectors and starts a connection for
+// `request`.
+//
+// request - The request to perform, must not be nil.
+// mapData - For each response, map the data received for that response to a
+//           result.
+//
+// Returns a signal which sends a tuple of the last response, and the first
+// value from the last `mapData`, then completes, or errors.
+- (RACSignal *)connectionSignalWithRequest:(NSURLRequest *)request mapData:(RACSignal * (^)(NSURLResponse *, RACSignal *))mapData;
+
+@end
+
+@implementation SQRLURLConnection
+
+- (instancetype)initWithRequest:(NSURLRequest *)request {
+	NSParameterAssert(request != nil);
+
+	self = [self init];
+	if (self == nil) return nil;
+
+	_request = [request copy];
+
+	return self;
+}
+
+- (RACSignal *)signalForDelegateSelector:(SEL)selector {
+	NSParameterAssert(selector != NULL);
+
+	return [[self
+		rac_signalForSelector:selector]
+		map:^(RACTuple *args) {
+			return args[1] ?: RACUnit.defaultUnit;
+		}];
+}
+
+- (RACSignal *)connectionSignalWithRequest:(NSURLRequest *)request mapData:(RACSignal * (^)(NSURLResponse *, RACSignal *))mapData {
+	return [[RACSignal
+		create:^(id<RACSubscriber> subscriber) {
+			// A signal that will error if the connection fails for any reason.
+			RACSignal *errors = [[self
+				signalForDelegateSelector:@selector(connection:didFailWithError:)]
+				flattenMap:^(NSError *error) {
+					return [RACSignal error:error];
+				}];
+
+			// Sends (or replays) RACUnit when the connection has finished
+			// loading successfully.
+			RACSignal *finished = [[[[self
+				signalForDelegateSelector:@selector(connectionDidFinishLoading:)]
+				take:1]
+				promiseOnScheduler:RACScheduler.immediateScheduler]
+				start];
+
+			// A signal of all `NSURLResponse`s received on the connection.
+			RACSignal *responses = [[self
+				signalForDelegateSelector:@selector(connection:didReceiveResponse:)]
+				takeUntil:finished];
+
+			// A signal of all `NSData` received on the connection.
+			RACSignal *data = [[self
+				signalForDelegateSelector:@selector(connection:didReceiveData:)]
+				takeUntil:finished];
+
+			[[[[[RACSignal
+				merge:@[ responses, errors ]]
+				takeUntil:finished]
+				map:^(NSURLResponse *response) {
+					return [RACSignal
+						zip:@[
+							[RACSignal return:response],
+							mapData(response, data),
+						]];
+				}]
+				switchToLatest]
+				subscribe:subscriber];
+
+			NSOperationQueue *delegateQueue = [[NSOperationQueue alloc] init];
+			delegateQueue.maxConcurrentOperationCount = 1;
+
+			NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self startImmediately:NO];
+			connection.delegateQueue = delegateQueue;
+
+			[connection start];
+
+			[subscriber.disposable addDisposable:[RACDisposable disposableWithBlock:^{
+				[connection cancel];
+			}]];
+		}]
+		setNameWithFormat:@"%@ %s %@", self, sel_getName(_cmd), request];
+}
+
+#pragma mark Download
+
+- (RACSignal *)truncateDownload:(SQRLDownload *)download {
+	NSParameterAssert(download != nil);
+
+	return [[[[RACSignal
+		defer:^{
+			NSError *error = nil;
+			BOOL remove = [NSFileManager.defaultManager removeItemAtURL:download.fileURL error:&error];
+			return (remove ? [RACSignal empty] : [RACSignal error:error]);
+		}]
+		catch:^(NSError *error) {
+			if ([error.domain isEqualToString:NSCocoaErrorDomain] && error.code == NSFileNoSuchFileError) return [RACSignal empty];
+			return [RACSignal error:error];
+		}]
+		concat:[RACSignal return:download]]
+		setNameWithFormat:@"%@ %s %@", self, sel_getName(_cmd), download];
+}
+
+- (RACSignal *)recordDownload:(SQRLResumableDownload *)download downloadManager:(SQRLDownloadManager *)downloadManager {
+	NSParameterAssert(download != nil);
+	NSParameterAssert(downloadManager != nil);
+
+	return [[[downloadManager
+		setDownload:download forRequest:self.request]
+		concat:[RACSignal return:download]]
+		setNameWithFormat:@"%@ %s %@", self, sel_getName(_cmd), download];
+}
+
+- (RACSignal *)prepareDownload:(SQRLDownload *)download downloadManager:(SQRLDownloadManager *)downloadManager forResponse:(NSURLResponse *)response {
+	return [[RACSignal
+		defer:^{
+			if (![response isKindOfClass:NSHTTPURLResponse.class]) {
+				return [self truncateDownload:download];
+			}
+
+			NSHTTPURLResponse *httpResponse = (id)response;
+
+			RACSignal *downloadSignal;
+			if (httpResponse.statusCode != 206 /* Partial Data */) {
+				downloadSignal = [self truncateDownload:download];
+			} else {
+				downloadSignal = [RACSignal empty];
+			}
+
+			SQRLResumableDownload *newDownload = [[SQRLResumableDownload alloc] initWithRequest:self.request response:httpResponse fileURL:download.fileURL];
+
+			return [[downloadSignal
+				ignoreValues]
+				concat:[self recordDownload:newDownload downloadManager:downloadManager]];
+		}]
+		setNameWithFormat:@"%@ %s %@", self, sel_getName(_cmd), response];
+}
+
+- (BOOL)appendData:(NSData *)data toURL:(NSURL *)fileURL error:(NSError **)errorRef {
+	NSOutputStream *outputStream = [NSOutputStream outputStreamWithURL:fileURL append:YES];
+
+	[outputStream open];
+	@onExit {
+		[outputStream close];
+	};
+
+	uint8_t const *bytes = data.bytes;
+	size_t length = data.length;
+	while (length > 0) {
+		NSInteger written = [outputStream write:bytes maxLength:length];
+		if (written == -1) {
+			NSError *streamError = outputStream.streamError;
+			if ([streamError.domain isEqualToString:NSPOSIXErrorDomain] && streamError.code == EINTR) continue;
+
+			if (errorRef != NULL) *errorRef = streamError;
+			return NO;
+		}
+		
+		bytes += written;
+		length -= written;
+	}
+
+	return YES;
+}
+
+#pragma mark Start
+
+- (RACSignal *)retrieve {
+	return [[self
+		connectionSignalWithRequest:self.request mapData:^(id _, RACSignal *data) {
+			return [data
+				aggregateWithStart:[NSMutableData data] reduce:^(NSMutableData *running, NSData *data) {
+					[running appendData:data];
+					return running;
+				}];
+		}]
+		setNameWithFormat:@"%@ %s", self, sel_getName(_cmd)];
+}
+
+- (RACSignal *)download:(SQRLDownloadManager *)downloadManager {
+	NSParameterAssert(downloadManager != nil);
+
+	RACSignal *download = [[[downloadManager
+		downloadForRequest:self.request]
+		promiseOnScheduler:RACScheduler.immediateScheduler]
+		deferred];
+
+	return [[[download
+		flattenMap:^(SQRLDownload *download) {
+			return [download resumableRequest];
+		}]
+		flattenMap:^(NSURLRequest *request) {
+			return [self connectionSignalWithRequest:request mapData:^(NSURLResponse *response, RACSignal *data) {
+				RACSignal *downloadURL = [[[[download
+					flattenMap:^(SQRLDownload *download) {
+						return [self prepareDownload:download downloadManager:downloadManager forResponse:response];
+					}]
+					map:^(SQRLDownload *download) {
+						return download.fileURL;
+					}]
+					promiseOnScheduler:RACScheduler.immediateScheduler]
+					deferred];
+
+				return [[[[data
+					map:^(NSData *bodyData) {
+						return [[downloadURL
+							try:^(NSURL *fileURL, NSError **errorRef) {
+								return [self appendData:bodyData toURL:fileURL error:errorRef];
+							}]
+							ignoreValues];
+					}]
+					concat]
+					ignoreValues]
+					concat:downloadURL];
+			}];
+		}]
+		setNameWithFormat:@"%@ download: %@", self, downloadManager];
+}
+
+@end

Squirrel/SQRLUpdate.m

@@ -14,6 +14,8 @@ NSString * const SQRLUpdateJSONReleaseNotesKey = @"notes";
 NSString * const SQRLUpdateJSONNameKey = @"name";
 NSString * const SQRLUpdateJSONPublicationDateKey = @"pub_date";
 
+NSString * const SQRLUpdateErrorDomain = @"SQRLUpdateErrorDomain";
+
 @implementation SQRLUpdate
 
 #pragma mark Lifecycle
@@ -50,7 +52,7 @@ NSString * const SQRLUpdateJSONPublicationDateKey = @"pub_date";
 
 			*error = [NSError errorWithDomain:NSCocoaErrorDomain code:NSKeyValueValidationError userInfo:userInfo];
 		}
-		
+
 		return NO;
 	}
 
@@ -61,10 +63,10 @@ NSString * const SQRLUpdateJSONPublicationDateKey = @"pub_date";
 
 + (NSDictionary *)JSONKeyPathsByPropertyKey {
 	return @{
-		@keypath(SQRLUpdate.new, releaseNotes): @"notes",
-		@keypath(SQRLUpdate.new, releaseName): @"name",
-		@keypath(SQRLUpdate.new, releaseDate): @"pub_date",
-		@keypath(SQRLUpdate.new, updateURL): @"url",
+		@keypath(SQRLUpdate.new, releaseNotes): SQRLUpdateJSONReleaseNotesKey,
+		@keypath(SQRLUpdate.new, releaseName): SQRLUpdateJSONNameKey,
+		@keypath(SQRLUpdate.new, releaseDate): SQRLUpdateJSONPublicationDateKey,
+		@keypath(SQRLUpdate.new, updateURL): SQRLUpdateJSONURLKey,
 	};
 }
 
@@ -94,8 +96,8 @@ NSString * const SQRLUpdateJSONPublicationDateKey = @"pub_date";
 		}
 
 		// If neither match, try removing the ':' in the time zone
-		static NSRegularExpression *timeZoneSuffix = nil;
-		static dispatch_once_t timeZoneSuffixPredicate = 0;
+		static NSRegularExpression *timeZoneSuffix;
+		static dispatch_once_t timeZoneSuffixPredicate;
 		dispatch_once(&timeZoneSuffixPredicate, ^ {
 			timeZoneSuffix = [NSRegularExpression regularExpressionWithPattern:@"([-+])([0-9]{2}):([0-9]{2})$" options:0 error:NULL];
 		});
@@ -142,7 +144,7 @@ NSString * const SQRLUpdateJSONPublicationDateKey = @"pub_date";
 			};
 			*error = [NSError errorWithDomain:NSCocoaErrorDomain code:NSKeyValueValidationError userInfo:userInfo];
 		}
-		
+
 		return NO;
 	}
 

Squirrel/SQRLUpdater.h

@@ -6,23 +6,6 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Foundation/Foundation.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-
-// Represents the current state of the updater.
-//
-// SQRLUpdaterStateIdle              - Doing absolutely diddly squat.
-// SQRLUpdaterStateCheckingForUpdate - Checking for any updates from the server.
-// SQRLUpdaterStateDownloadingUpdate - Update found, downloading the archive.
-// SQRLUpdaterStateAwaitingRelaunch  - Awaiting a relaunch to install
-//                                     the update.
-typedef enum : NSUInteger {
-       SQRLUpdaterStateIdle,
-       SQRLUpdaterStateCheckingForUpdate,
-       SQRLUpdaterStateDownloadingUpdate,
-       SQRLUpdaterStateAwaitingRelaunch,
-} SQRLUpdaterState;
-
 // The domain for errors originating within SQRLUpdater.
 extern NSString * const SQRLUpdaterErrorDomain;
 
@@ -60,7 +43,7 @@ extern NSString * const SQRLUpdaterServerDataErrorKey;
 // error with code `SQRLUpdaterErrorInvalidJSON` is generated.
 extern NSString * const SQRLUpdaterJSONObjectErrorKey;
 
-@class RACCommand;
+@class RACAction;
 @class RACDisposable;
 @class RACSignal;
 
@@ -69,19 +52,12 @@ extern NSString * const SQRLUpdaterJSONObjectErrorKey;
 
 // Kicks off a check for updates.
 //
-// If an update is available, it will be sent on `updates` once downloaded.
-@property (nonatomic, strong, readonly) RACCommand *checkForUpdatesCommand;
-
-// The current state of the manager.
-//
-// This property is KVO-compliant.
-@property (atomic, readonly) SQRLUpdaterState state;
+// If an update is available, it will be sent on
+// `[checkForUpdatesAction deferred]` and `updates` once downloaded.
+@property (nonatomic, strong, readonly) RACAction *checkForUpdatesAction;
 
 // Sends an `SQRLDownloadedUpdate` object on the main thread whenever a new
-// update is available.
-//
-// This signal is actually just `checkForUpdatesCommand.executionSignals`,
-// flattened for convenience.
+// update is available. Completes when the receiver deallocates.
 @property (nonatomic, strong, readonly) RACSignal *updates;
 
 // The request that will be sent to check for updates.

Squirrel/SQRLUpdater.m

@@ -15,11 +15,15 @@
 #import "SQRLDirectoryManager.h"
 #import "SQRLDownloadedUpdate.h"
 #import "SQRLShipItLauncher.h"
+#import "SQRLShipItState.h"
 #import "SQRLUpdate.h"
+#import "SQRLDownloadedUpdate.h"
 #import "SQRLZipArchiver.h"
-#import "SQRLShipItRequest.h"
 #import <ReactiveCocoa/EXTScope.h>
 #import <ReactiveCocoa/ReactiveCocoa.h>
+#import "SQRLURLConnection.h"
+#import "SQRLURLConnection.h"
+#import "SQRLDownloadManager.h"
 
 NSString * const SQRLUpdaterErrorDomain = @"SQRLUpdaterErrorDomain";
 NSString * const SQRLUpdaterServerDataErrorKey = @"SQRLUpdaterServerDataErrorKey";
@@ -32,13 +36,10 @@ const NSInteger SQRLUpdaterErrorInvalidServerResponse = 5;
 const NSInteger SQRLUpdaterErrorInvalidJSON = 6;
 const NSInteger SQRLUpdaterErrorInvalidServerBody = 7;
 
-// The prefix used when creating temporary directories for updates. This will be
-// followed by a random string of characters.
-static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
-
 @interface SQRLUpdater ()
 
-@property (atomic, readwrite) SQRLUpdaterState state;
+// The directory manager used for downloads and unpacks.
+@property (nonatomic, strong, readonly) SQRLDirectoryManager *directoryManager;
 
 // The code signature for the running application, used to check updates before
 // sending them to ShipIt.
@@ -49,16 +50,6 @@ static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 // Sends completed or error.
 @property (nonatomic, strong, readonly) RACSignal *shipItLauncher;
 
-// Lazily removes outdated temporary directories (used for previous updates)
-// upon first subscription.
-//
-// Pruning directories while an update is pending or in progress will result in
-// undefined behavior.
-//
-// Sends each removed directory then completes, or errors, on an unspecified
-// thread.
-@property (nonatomic, strong, readonly) RACSignal *prunedUpdateDirectories;
-
 // Parses an update model from downloaded data.
 //
 // data - JSON data representing an update manifest. This must not be nil.
@@ -78,22 +69,25 @@ static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 // errors, on a background thread.
 - (RACSignal *)downloadAndPrepareUpdate:(SQRLUpdate *)update;
 
-// Downloads the archived bundle associated with the given update.
+// Downloads the update archive for the given update.
 //
 // update            - Describes the update to install. This must not be nil.
-// downloadDirectory - A directory in which to create a temporary directory for this
-//                     download. This must not be nil.
+// downloadDirectory - A directory in which to create a temporary directory for
+//                     this download. This must not be nil.
 //
-// Returns a signal which sends an unarchived `NSBundle` then completes, or
-// errors, on a background thread.
-- (RACSignal *)downloadBundleForUpdate:(SQRLUpdate *)update intoDirectory:(NSURL *)downloadDirectory;
+// Returns a signal which sends an NSURL of the downloaded update archive then
+// completes, or errors, on a background thread.
+- (RACSignal *)downloadArchiveForUpdate:(SQRLUpdate *)update intoDirectory:(NSURL *)downloadDirectory;
 
-// Creates a unique directory in which to save the update bundle, for later use
-// by ShipIt.
+// Unpacks an update archive.
 //
-// Returns a signal which sends an `NSURL` then completes, or errors, on an
-// unspecified thread.
-- (RACSignal *)uniqueTemporaryDirectoryForUpdate;
+// archiveURL   - The location of the update archive, currently only ZIP
+//                archives are supported. Must not be nil.
+// directoryURL - A directory in which to place the unpacked contents of the
+//                archive. Must not be nil.
+//
+// Returns a signal which completes or errors.
+- (RACSignal *)unpackArchiveAtURL:(NSURL *)archiveURL intoDirectory:(NSURL *)directoryURL;
 
 // Recursively searches the given directory for an application bundle that has
 // the same identifier as the running application.
@@ -126,16 +120,27 @@ static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 // Returns a signal which completes or errors on a background thread.
 - (RACSignal *)prepareUpdateForInstallation:(SQRLDownloadedUpdate *)update;
 
+// Verifies that an existing state is innocuous, and therefore safe to
+// overwrite.
+//
+// This won't be the case if, for example, an update is currently being
+// installed.
+//
+// Returns a signal which sends `existingState` then completes upon successful
+// validation, or errors otherwise.
+- (RACSignal *)validateExistingState:(SQRLShipItState *)existingState;
+
 @end
 
-@implementation SQRLUpdater
+@implementation SQRLUpdater {
+	RACSubject *_updates;
+}
 
 #pragma mark Properties
 
 - (RACSignal *)updates {
-	return [[self.checkForUpdatesCommand.executionSignals
-		concat]
-		setNameWithFormat:@"%@ -updates", self];
+	return [_updates
+		deliverOn:RACScheduler.mainThreadScheduler];
 }
 
 #pragma mark Lifecycle
@@ -154,110 +159,29 @@ static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 	_updateRequest = [updateRequest copy];
 	_updateClass = SQRLUpdate.class;
 
+	_directoryManager = SQRLDirectoryManager.currentApplicationManager;
+
 	NSError *error = nil;
 	_signature = [SQRLCodeSignature currentApplicationSignature:&error];
-	if (_signature == nil) {
-#if DEBUG
-		NSLog(@"Could not get code signature for running application, application updates are disabled: %@", error);
-		return nil;
-#else
-		NSDictionary *exceptionInfo = @{ NSUnderlyingErrorKey: error };
-		@throw [NSException exceptionWithName:NSInternalInconsistencyException reason:@"Could not get code signature for running application" userInfo:exceptionInfo];
-#endif
-	}
+	NSAssert(_signature != nil, @"Could not get code signature for running application: %@", error);
 
-	BOOL updatesDisabled = (getenv("DISABLE_UPDATE_CHECK") != NULL);
 	@weakify(self);
-
-	_prunedUpdateDirectories = [[[[RACSignal
+	_checkForUpdatesAction = [[[RACSignal
 		defer:^{
-			SQRLDirectoryManager *directoryManager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:SQRLShipItLauncher.shipItJobLabel];
-			return [directoryManager applicationSupportURL];
+			@strongify(self);
+			return [RACSignal return:self.updateRequest];
 		}]
-		flattenMap:^(NSURL *appSupportURL) {
-			NSFileManager *manager = [[NSFileManager alloc] init];
-			NSDirectoryEnumerator *enumerator = [manager enumeratorAtURL:appSupportURL includingPropertiesForKeys:nil options:NSDirectoryEnumerationSkipsSubdirectoryDescendants errorHandler:^(NSURL *URL, NSError *error) {
-				NSLog(@"Error enumerating item %@ within directory %@: %@", URL, appSupportURL, error);
-				return YES;
-			}];
-
-			return [[enumerator.rac_sequence.signal
-				filter:^(NSURL *enumeratedURL) {
-					NSString *name = enumeratedURL.lastPathComponent;
-					return [name hasPrefix:SQRLUpdaterUniqueTemporaryDirectoryPrefix];
-				}]
-				doNext:^(NSURL *directoryURL) {
-					NSError *error = nil;
-					if (![manager removeItemAtURL:directoryURL error:&error]) {
-						NSLog(@"Error removing old update directory at %@: %@", directoryURL, error.sqrl_verboseDescription);
-					}
-				}];
+		flattenMap:^(NSURLRequest *request) {
+			@strongify(self);
+			return [self checkForUpdates:request];
 		}]
-		replayLazily]
-		setNameWithFormat:@"%@ -prunedUpdateDirectories", self];
+		action];
 
-	_checkForUpdatesCommand = [[RACCommand alloc] initWithEnabled:[RACSignal return:@(!updatesDisabled)] signalBlock:^(id _) {
-		@strongify(self);
-		NSParameterAssert(self.updateRequest != nil);
+	_updates = [[RACSubject
+		subject]
+		setNameWithFormat:@"%@ updates", self];
 
-		// TODO: Maybe allow this to be an argument to the command?
-		NSMutableURLRequest *request = [self.updateRequest mutableCopy];
-		[request setValue:@"application/json" forHTTPHeaderField:@"Accept"];
-
-		// Prune old updates before the first update check.
-		return [[[[[[[[self.prunedUpdateDirectories
-			catch:^(NSError *error) {
-				NSLog(@"Error pruning old updates: %@", error);
-				return [RACSignal empty];
-			}]
-			then:^{
-				self.state = SQRLUpdaterStateCheckingForUpdate;
-
-				return [NSURLConnection rac_sendAsynchronousRequest:request];
-			}]
-			reduceEach:^(NSURLResponse *response, NSData *bodyData) {
-				if ([response isKindOfClass:NSHTTPURLResponse.class]) {
-					NSHTTPURLResponse *httpResponse = (id)response;
-					if (!(httpResponse.statusCode >= 200 && httpResponse.statusCode <= 299)) {
-						NSDictionary *errorInfo = @{
-							NSLocalizedDescriptionKey: NSLocalizedString(@"Update check failed", nil),
-							NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"The server sent an invalid response. Try again later.", nil),
-							SQRLUpdaterServerDataErrorKey: bodyData,
-						};
-						NSError *error = [NSError errorWithDomain:SQRLUpdaterErrorDomain code:SQRLUpdaterErrorInvalidServerResponse userInfo:errorInfo];
-						return [RACSignal error:error];
-					}
-
-					if (httpResponse.statusCode == 204 /* No Content */) {
-						return [RACSignal empty];
-					}
-				}
-
-				return [RACSignal return:bodyData];
-			}]
-			flatten]
-			flattenMap:^(NSData *data) {
-				return [self updateFromJSONData:data];
-			}]
-			flattenMap:^(SQRLUpdate *update) {
-				return [[RACSignal
-					defer:^{
-						self.state = SQRLUpdaterStateDownloadingUpdate;
-
-						return [self downloadAndPrepareUpdate:update];
-					}]
-					doCompleted:^{
-						self.state = SQRLUpdaterStateAwaitingRelaunch;
-					}];
-			}]
-			finally:^{
-				if (self.state == SQRLUpdaterStateAwaitingRelaunch) return;
-				self.state = SQRLUpdaterStateIdle;
-			}]
-			deliverOn:RACScheduler.mainThreadScheduler];
-	}];
-
-	_shipItLauncher = [[[RACSignal
+	_shipItLauncher = [[[[RACSignal
 		defer:^{
 			NSURL *targetURL = NSRunningApplication.currentApplication.bundleURL;
 
@@ -269,31 +193,80 @@ static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 			// wait for another, more canonical error.
 			return [SQRLShipItLauncher launchPrivileged:(gotWritable && !targetWritable.boolValue)];
 		}]
-		replayLazily]
+		promiseOnScheduler:RACScheduler.immediateScheduler]
+		deferred]
 		setNameWithFormat:@"shipItLauncher"];
-	
+
 	return self;
 }
 
+- (void)dealloc {
+	[_updates sendCompleted];
+}
+
 #pragma mark Checking for Updates
 
 - (RACDisposable *)startAutomaticChecksWithInterval:(NSTimeInterval)interval {
 	@weakify(self);
 
-	return [[[[[RACSignal
+	return [[[[RACSignal
 		interval:interval onScheduler:[RACScheduler schedulerWithPriority:RACSchedulerPriorityBackground]]
 		flattenMap:^(id _) {
 			@strongify(self);
-			return [[self.checkForUpdatesCommand
-				execute:RACUnit.defaultUnit]
+
+			return [[[self.checkForUpdatesAction
+				deferred]
+				ignoreValues]
 				catch:^(NSError *error) {
 					NSLog(@"Error checking for updates: %@", error);
 					return [RACSignal empty];
 				}];
 		}]
 		takeUntil:self.rac_willDeallocSignal]
-		publish]
-		connect];
+		subscribeCompleted:^{}];
+}
+
+- (RACSignal *)checkForUpdates:(NSURLRequest *)request {
+	NSParameterAssert(request != nil);
+
+	BOOL updatesDisabled = (getenv("DISABLE_UPDATE_CHECK") != NULL);
+	if (updatesDisabled) return [RACSignal empty];
+
+	NSMutableURLRequest *newRequest = [request mutableCopy];
+	[newRequest setValue:@"application/json" forHTTPHeaderField:@"Accept"];
+
+	return [[[[[[NSURLConnection
+		rac_sendAsynchronousRequest:newRequest]
+		reduceEach:^(NSURLResponse *response, NSData *bodyData) {
+		if ([response isKindOfClass:NSHTTPURLResponse.class]) {
+			NSHTTPURLResponse *httpResponse = (id)response;
+			if (!(httpResponse.statusCode >= 200 && httpResponse.statusCode <= 299)) {
+				NSDictionary *errorInfo = @{
+					NSLocalizedDescriptionKey: NSLocalizedString(@"Update check failed", nil),
+					NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"The server sent an invalid response. Try again later.", nil),
+					SQRLUpdaterServerDataErrorKey: bodyData,
+				};
+				NSError *error = [NSError errorWithDomain:SQRLUpdaterErrorDomain code:SQRLUpdaterErrorInvalidServerResponse userInfo:errorInfo];
+				return [RACSignal error:error];
+			}
+
+			if (httpResponse.statusCode == 204 /* No Content */) {
+				return [RACSignal empty];
+			}
+		}
+
+		return [RACSignal return:bodyData];
+	}]
+	flatten]
+	flattenMap:^(NSData *data) {
+		return [self updateFromJSONData:data];
+	}]
+	flattenMap:^(SQRLUpdate *update) {
+		return [self downloadAndPrepareUpdate:update];
+	}]
+	doNext:^(SQRLDownloadedUpdate *update) {
+		[self->_updates sendNext:update];
+	}];
 }
 
 - (RACSignal *)updateFromJSONData:(NSData *)data {
@@ -335,14 +308,21 @@ static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 		setNameWithFormat:@"%@ -updateFromJSONData:", self];
 }
 
+#pragma Download
+
 - (RACSignal *)downloadAndPrepareUpdate:(SQRLUpdate *)update {
 	NSParameterAssert(update != nil);
 
-	return [[[self
-		uniqueTemporaryDirectoryForUpdate]
+	return [[[self.directoryManager
+		createUniqueUpdateDirectoryURL]
 		flattenMap:^(NSURL *downloadDirectory) {
-			return [[[self
-				downloadBundleForUpdate:update intoDirectory:downloadDirectory]
+			return [[[[[[self
+				downloadArchiveForUpdate:update intoDirectory:downloadDirectory]
+				flattenMap:^(NSURL *updateArchiveURL) {
+					return [self unpackArchiveAtURL:updateArchiveURL intoDirectory:downloadDirectory];
+				}]
+				ignoreValues]
+				concat:[self updateBundleMatchingCurrentApplicationInDirectory:downloadDirectory]]
 				flattenMap:^(NSBundle *updateBundle) {
 					return [self verifyAndPrepareUpdate:update fromBundle:updateBundle];
 				}]
@@ -356,95 +336,65 @@ static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 		setNameWithFormat:@"%@ -downloadAndPrepareUpdate: %@", self, update];
 }
 
-- (RACSignal *)downloadBundleForUpdate:(SQRLUpdate *)update intoDirectory:(NSURL *)downloadDirectory {
+- (RACSignal *)downloadArchiveForUpdate:(SQRLUpdate *)update intoDirectory:(NSURL *)downloadDirectory {
 	NSParameterAssert(update != nil);
 	NSParameterAssert(downloadDirectory != nil);
 
-	return [[[[[RACSignal
+	return [[[RACSignal
 		defer:^{
 			NSURL *zipDownloadURL = update.updateURL;
 			NSMutableURLRequest *zipDownloadRequest = [NSMutableURLRequest requestWithURL:zipDownloadURL];
 			[zipDownloadRequest setValue:@"application/zip" forHTTPHeaderField:@"Accept"];
 
-			return [[[[NSURLConnection
-				rac_sendAsynchronousRequest:zipDownloadRequest]
-				reduceEach:^(NSURLResponse *response, NSData *bodyData) {
+			SQRLURLConnection *connection = [[SQRLURLConnection alloc] initWithRequest:zipDownloadRequest];
+
+			SQRLDownloadManager *downloadManager = [[SQRLDownloadManager alloc] initWithDirectoryManager:self.directoryManager];
+
+			return [[[[connection
+				download:downloadManager]
+				reduceEach:^(NSURLResponse *response, NSURL *bodyLocation) {
 					if ([response isKindOfClass:NSHTTPURLResponse.class]) {
 						NSHTTPURLResponse *httpResponse = (id)response;
 						if (!(httpResponse.statusCode >= 200 && httpResponse.statusCode <= 299)) {
 							NSDictionary *errorInfo = @{
 								NSLocalizedDescriptionKey: NSLocalizedString(@"Update download failed", nil),
 								NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"The server sent an invalid response. Try again later.", nil),
-								SQRLUpdaterServerDataErrorKey: bodyData,
 							};
 							NSError *error = [NSError errorWithDomain:SQRLUpdaterErrorDomain code:SQRLUpdaterErrorInvalidServerResponse userInfo:errorInfo];
 							return [RACSignal error:error];
 						}
 					}
 
-					return [RACSignal return:bodyData];
+					return [[RACSignal
+						return:bodyLocation]
+						tryMap:^ NSURL * (NSURL *bodyLocation, NSError **errorRef) {
+							NSURL *updateLocation = [downloadDirectory URLByAppendingPathComponent:response.suggestedFilename];
+							if (![NSFileManager.defaultManager moveItemAtURL:bodyLocation toURL:updateLocation error:errorRef]) return nil;
+							return updateLocation;
+						}];
 				}]
 				flatten]
-				flattenMap:^(NSData *data) {
-					NSURL *zipOutputURL = [downloadDirectory URLByAppendingPathComponent:zipDownloadURL.lastPathComponent];
-
-					NSError *error = nil; 
-					if ([data writeToURL:zipOutputURL options:NSDataWritingAtomic error:&error]) {
-						return [RACSignal return:zipOutputURL];
-					} else {
-						return [RACSignal error:error];
-					}
-				}];
+				concat:[[downloadManager
+					removeAllResumableDownloads]
+					catchTo:RACSignal.empty]];
 		}]
 		doNext:^(NSURL *zipOutputURL) {
 			NSLog(@"Download completed to: %@", zipOutputURL);
 		}]
-		flattenMap:^(NSURL *zipOutputURL) {
-			return [[SQRLZipArchiver
-				unzipArchiveAtURL:zipOutputURL intoDirectoryAtURL:downloadDirectory]
-				doCompleted:^{
-					NSError *error = nil;
-					if (![NSFileManager.defaultManager removeItemAtURL:zipOutputURL error:&error]) {
-						NSLog(@"Error removing downloaded archive at %@: %@", zipOutputURL, error.sqrl_verboseDescription);
-					}
-				}];
-		}]
-		then:^{
-			return [self updateBundleMatchingCurrentApplicationInDirectory:downloadDirectory];
-		}]
-		setNameWithFormat:@"%@ -downloadBundleForUpdate: %@ intoDirectory: %@", self, update, downloadDirectory];
+		setNameWithFormat:@"%@ -downloadArchiveForUpdate: %@ intoDirectory: %@", self, update, downloadDirectory];
 }
 
 #pragma mark File Management
 
-- (RACSignal *)uniqueTemporaryDirectoryForUpdate {
-	return [[[RACSignal
+- (RACSignal *)unpackArchiveAtURL:(NSURL *)archiveURL intoDirectory:(NSURL *)directoryURL {
+	NSParameterAssert(archiveURL != nil);
+	NSParameterAssert(directoryURL != nil);
+
+	return [[RACSignal
 		defer:^{
-			SQRLDirectoryManager *directoryManager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:SQRLShipItLauncher.shipItJobLabel];
-			return [directoryManager applicationSupportURL];
+			return [SQRLZipArchiver unzipArchiveAtURL:archiveURL intoDirectoryAtURL:directoryURL];
 		}]
-		flattenMap:^(NSURL *appSupportURL) {
-			NSURL *updateDirectoryTemplate = [appSupportURL URLByAppendingPathComponent:[SQRLUpdaterUniqueTemporaryDirectoryPrefix stringByAppendingString:@"XXXXXXX"]];
-			char *updateDirectoryCString = strdup(updateDirectoryTemplate.path.fileSystemRepresentation);
-			@onExit {
-				free(updateDirectoryCString);
-			};
-			
-			if (mkdtemp(updateDirectoryCString) == NULL) {
-				int code = errno;
-
-				NSDictionary *userInfo = @{
-					NSLocalizedDescriptionKey: NSLocalizedString(@"Could not create temporary directory", nil),
-					NSURLErrorKey: updateDirectoryTemplate
-				};
-
-				return [RACSignal error:[NSError errorWithDomain:NSPOSIXErrorDomain code:code userInfo:userInfo]];
-			}
-
-			NSString *updateDirectoryPath = [NSFileManager.defaultManager stringWithFileSystemRepresentation:updateDirectoryCString length:strlen(updateDirectoryCString)];
-			return [RACSignal return:[NSURL fileURLWithPath:updateDirectoryPath isDirectory:YES]];
-		}]
-		setNameWithFormat:@"%@ -uniqueTemporaryDirectoryForUpdate", self];
+		setNameWithFormat:@"%@ unpackArchiveAtURL: %@ intoDirectory: %@", self, archiveURL, directoryURL];
 }
 
 - (RACSignal *)updateBundleMatchingCurrentApplicationInDirectory:(NSURL *)directory {
@@ -457,25 +407,28 @@ static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 				NSLog(@"Error enumerating item %@ within directory %@: %@", URL, directory, error);
 				return YES;
 			}];
-			
-			NSURL *updateBundleURL = [enumerator.rac_sequence objectPassingTest:^(NSURL *URL) {
-				NSString *type = nil;
-				NSError *error = nil;
-				if (![URL getResourceValue:&type forKey:NSURLTypeIdentifierKey error:&error]) {
-					NSLog(@"Error retrieving UTI for item at %@: %@", URL, error);
-					return NO;
-				}
 
-				if (!UTTypeConformsTo((__bridge CFStringRef)type, kUTTypeApplicationBundle)) return NO;
+			NSURL *updateBundleURL = [[[enumerator.rac_promise
+				start]
+				filter:^(NSURL *URL) {
+					NSString *type = nil;
+					NSError *error = nil;
+					if (![URL getResourceValue:&type forKey:NSURLTypeIdentifierKey error:&error]) {
+						NSLog(@"Error retrieving UTI for item at %@: %@", URL, error);
+						return NO;
+					}
 
-				NSBundle *bundle = [NSBundle bundleWithURL:URL];
-				if (bundle == nil) {
-					NSLog(@"Could not open application bundle at %@", URL);
-					return NO;
-				}
+					if (!UTTypeConformsTo((__bridge CFStringRef)type, kUTTypeApplicationBundle)) return NO;
 
-				return [bundle.bundleIdentifier isEqual:NSRunningApplication.currentApplication.bundleIdentifier];
-			}];
+					NSBundle *bundle = [NSBundle bundleWithURL:URL];
+					if (bundle == nil) {
+						NSLog(@"Could not open application bundle at %@", URL);
+						return NO;
+					}
+
+					return [bundle.bundleIdentifier isEqual:NSRunningApplication.currentApplication.bundleIdentifier];
+				}]
+				first];
 
 			if (updateBundleURL != nil) {
 				return [RACSignal return:updateBundleURL];
@@ -510,42 +463,62 @@ static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 
 	return [[[[self.signature
 		verifyBundleAtURL:updateBundle.bundleURL]
-		then:^{
-			SQRLDownloadedUpdate *downloadedUpdate = [[SQRLDownloadedUpdate alloc] initWithUpdate:update bundle:updateBundle];
-			return [RACSignal return:downloadedUpdate];
-		}]
+		concat:[RACSignal return:[[SQRLDownloadedUpdate alloc] initWithUpdate:update bundle:updateBundle]]]
 		flattenMap:^(SQRLDownloadedUpdate *downloadedUpdate) {
-			return [[self prepareUpdateForInstallation:downloadedUpdate] then:^{
-				return [RACSignal return:downloadedUpdate];
-			}];
+			return [[self
+				prepareUpdateForInstallation:downloadedUpdate]
+				concat:[RACSignal return:downloadedUpdate]];
 		}]
 		setNameWithFormat:@"%@ -verifyAndPrepareUpdate: %@ fromBundle: %@", self, update, updateBundle];
 }
 
+- (RACSignal *)validateExistingState:(SQRLShipItState *)existingState {
+	return [[RACSignal
+		defer:^{
+			if (existingState.installerState != SQRLInstallerStateNothingToDo) {
+				// If this happens, shit is crazy, because it implies that an
+				// update is being installed over us right now.
+				NSDictionary *userInfo = @{
+					NSLocalizedDescriptionKey: NSLocalizedString(@"Installation in progress", nil),
+					NSLocalizedRecoverySuggestionErrorKey: [NSString stringWithFormat:NSLocalizedString(@"An update for %@ is already in progress.", nil), NSRunningApplication.currentApplication.bundleIdentifier],
+				};
+
+				return [RACSignal error:[NSError errorWithDomain:SQRLUpdaterErrorDomain code:SQRLUpdaterErrorPreparingUpdateJob userInfo:userInfo]];
+			}
+
+			return [RACSignal return:existingState];
+		}]
+		setNameWithFormat:@"%@ -validateExistingState: %@", self, existingState];
+}
+
 - (RACSignal *)prepareUpdateForInstallation:(SQRLDownloadedUpdate *)update {
 	NSParameterAssert(update != nil);
 
-	return [[[[RACSignal
-		defer:^{
-			NSRunningApplication *currentApplication = NSRunningApplication.currentApplication;
-			SQRLShipItRequest *request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:update.bundle.bundleURL targetBundleURL:currentApplication.bundleURL bundleIdentifier:currentApplication.bundleIdentifier launchAfterInstallation:NO];
-			return [request writeUsingURL:self.shipItStateURL];
-		}]
-		then:^{
-			return self.shipItLauncher;
+	return [[[[[[[[SQRLShipItState
+		readUsingURL:self.shipItStateURL]
+		catchTo:[RACSignal empty]]
+		flattenMap:^(SQRLShipItState *existingState) {
+			return [self validateExistingState:existingState];
 		}]
+		ignoreValues]
+		concat:[RACSignal defer:^{
+			SQRLShipItState *state = [[SQRLShipItState alloc] initWithTargetBundleURL:NSRunningApplication.currentApplication.bundleURL updateBundleURL:update.bundle.bundleURL bundleIdentifier:NSRunningApplication.currentApplication.bundleIdentifier codeSignature:self.signature];
+			return [state writeUsingURL:self.shipItStateURL];
+		}]]
+		concat:self.shipItLauncher]
 		sqrl_addTransactionWithName:NSLocalizedString(@"Preparing update", nil) description:NSLocalizedString(@"An update for %@ is being prepared. Interrupting the process could corrupt the application.", nil), NSRunningApplication.currentApplication.bundleIdentifier]
 		setNameWithFormat:@"%@ -prepareUpdateForInstallation: %@", self, update];
 }
 
 - (RACSignal *)relaunchToInstallUpdate {
-	return [[[[[[[[SQRLShipItRequest
+	return [[[[[[[[[SQRLShipItState
 		readUsingURL:self.shipItStateURL]
-		map:^(SQRLShipItRequest *request) {
-			return [[SQRLShipItRequest alloc] initWithUpdateBundleURL:request.updateBundleURL targetBundleURL:request.targetBundleURL bundleIdentifier:request.bundleIdentifier launchAfterInstallation:YES];
+		flattenMap:^(SQRLShipItState *existingState) {
+			return [self validateExistingState:existingState];
 		}]
-		flattenMap:^(SQRLShipItRequest *request) {
-			return [[request
+		flattenMap:^(SQRLShipItState *state) {
+			state.relaunchAfterInstallation = YES;
+			return [[state
 				writeUsingURL:self.shipItStateURL]
 				sqrl_addTransactionWithName:NSLocalizedString(@"Preparing to relaunch", nil) description:NSLocalizedString(@"%@ is preparing to relaunch to install an update. Interrupting the process could corrupt the application.", nil), NSRunningApplication.currentApplication.bundleIdentifier];
 		}]
@@ -556,7 +529,8 @@ static NSString * const SQRLUpdaterUniqueTemporaryDirectoryPrefix = @"update.";
 		// Never allow `completed` to escape this signal chain (in case
 		// -terminate: is asynchronous or something crazy).
 		concat:[RACSignal never]]
-		replay]
+		promiseOnScheduler:RACScheduler.immediateScheduler]
+		deferred]
 		setNameWithFormat:@"%@ -relaunchToInstallUpdate", self];
 }
 

Squirrel/SQRLZipArchiver.m

@@ -130,25 +130,23 @@ const NSInteger SQRLZipArchiverShellTaskFailed = 1;
 		// This is important because the signals on `self` complete upon
 		// dealloc.
 		return:self]
-		then:^{
-			return [RACSignal
-				zip:@[ self.taskTerminated, self.standardErrorData ]
-				reduce:^(NSNumber *exitStatus, NSData *errorData) {
-					if (exitStatus.intValue == 0) return [RACSignal empty];
+		ignoreValues]
+		concat:[RACSignal
+			zip:@[ self.taskTerminated, self.standardErrorData ]
+			reduce:^(NSNumber *exitStatus, NSData *errorData) {
+				if (exitStatus.intValue == 0) return [RACSignal empty];
 
-					NSMutableDictionary *userInfo = [NSMutableDictionary dictionary];
-					userInfo[SQRLZipArchiverExitCodeErrorKey] = exitStatus;
+				NSMutableDictionary *userInfo = [NSMutableDictionary dictionary];
+				userInfo[SQRLZipArchiverExitCodeErrorKey] = exitStatus;
 
-					NSString *errorString = [[NSString alloc] initWithData:errorData encoding:NSUTF8StringEncoding];
-					errorString = [errorString stringByTrimmingCharactersInSet:NSCharacterSet.whitespaceAndNewlineCharacterSet];
-					if (errorString.length > 0) userInfo[NSLocalizedDescriptionKey] = errorString;
+				NSString *errorString = [[NSString alloc] initWithData:errorData encoding:NSUTF8StringEncoding];
+				errorString = [errorString stringByTrimmingCharactersInSet:NSCharacterSet.whitespaceAndNewlineCharacterSet];
+				if (errorString.length > 0) userInfo[NSLocalizedDescriptionKey] = errorString;
 
-					return [RACSignal error:[NSError errorWithDomain:SQRLZipArchiverErrorDomain code:SQRLZipArchiverShellTaskFailed userInfo:userInfo]];
-				}];
-		}]
+				return [RACSignal error:[NSError errorWithDomain:SQRLZipArchiverErrorDomain code:SQRLZipArchiverShellTaskFailed userInfo:userInfo]];
+			}]]
 		take:1]
 		flatten]
-		replay]
 		setNameWithFormat:@"-launchWithArguments: %@", arguments];
 
 	self.dittoTask.arguments = arguments;

Squirrel/ShipIt-main.m

@@ -7,19 +7,15 @@
 //
 
 #import <Foundation/Foundation.h>
-
-#import "EXTScope.h"
-#import <ReactiveCocoa/RACCommand.h>
-#import <ReactiveCocoa/RACSignal+Operations.h>
-#import <ReactiveCocoa/RACScheduler.h>
-
+#import <ReactiveCocoa/EXTScope.h>
+#import <ReactiveCocoa/ReactiveCocoa.h>
 #import "NSError+SQRLVerbosityExtensions.h"
 #import "RACSignal+SQRLTransactionExtensions.h"
+#import "SQRLCodeSignature.h"
 #import "SQRLDirectoryManager.h"
 #import "SQRLInstaller.h"
-#import "SQRLInstaller+Private.h"
+#import "SQRLShipItState.h"
 #import "SQRLTerminationListener.h"
-#import "SQRLShipItRequest.h"
 
 // The maximum number of times ShipIt should run the same installation state, in
 // an attempt to update.
@@ -31,116 +27,19 @@ static const NSUInteger SQRLShipItMaximumInstallationAttempts = 3;
 // The domain for errors generated here.
 static NSString * const SQRLShipItErrorDomain = @"SQRLShipItErrorDomain";
 
-static NSUInteger installationAttempts(NSString *applicationIdentifier) {
-	return CFPreferencesGetAppIntegerValue((__bridge CFStringRef)SQRLShipItInstallationAttemptsKey, (__bridge CFStringRef)applicationIdentifier, NULL);
-}
-
-static BOOL setInstallationAttempts(NSString *applicationIdentifier, NSUInteger attempts) {
-	CFPreferencesSetValue((__bridge CFStringRef)SQRLShipItInstallationAttemptsKey, (__bridge CFPropertyListRef)@(attempts), (__bridge CFStringRef)applicationIdentifier, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost);
-	return CFPreferencesSynchronize((__bridge CFStringRef)applicationIdentifier, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost);
-}
-
-static BOOL clearInstallationAttempts(NSString *applicationIdentifier) {
-	CFPreferencesSetValue((__bridge CFStringRef)SQRLShipItInstallationAttemptsKey, NULL, (__bridge CFStringRef)applicationIdentifier, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost);
-	return CFPreferencesSynchronize((__bridge CFStringRef)applicationIdentifier, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost);
-}
-
 // Waits for all instances of the target application (as described in the
-// `request`) to exit, then sends completed.
-static RACSignal *waitForTerminationIfNecessary(SQRLShipItRequest *request) {
+// `state`) to exit, then sends completed.
+static RACSignal *waitForTerminationIfNecessary(SQRLShipItState *state) {
 	return [[RACSignal
 		defer:^{
-			if (request.bundleIdentifier == nil) return [RACSignal empty];
+			if (state.bundleIdentifier == nil) return [RACSignal empty];
 
-			SQRLTerminationListener *listener = [[SQRLTerminationListener alloc] initWithURL:request.targetBundleURL bundleIdentifier:request.bundleIdentifier];
+			SQRLTerminationListener *listener = [[SQRLTerminationListener alloc] initWithURL:state.targetBundleURL bundleIdentifier:state.bundleIdentifier];
 			return [listener waitForTermination];
 		}]
 		setNameWithFormat:@"waitForTerminationIfNecessary"];
 }
 
-static void installRequest(RACSignal *readRequestSignal, SQRLDirectoryManager *directoryManager) {
-	NSString *applicationIdentifier = directoryManager.applicationIdentifier;
-
-	[[[[[readRequestSignal
-		flattenMap:^(SQRLShipItRequest *request) {
-			return waitForTerminationIfNecessary(request);
-		}]
-		ignoreValues]
-		concat:readRequestSignal]
-		flattenMap:^(SQRLShipItRequest *request) {
-			SQRLInstaller *installer = [[SQRLInstaller alloc] initWithApplicationIdentifier:applicationIdentifier];
-
-			NSUInteger attempt = installationAttempts(applicationIdentifier) + 1;
-			setInstallationAttempts(applicationIdentifier, attempt);
-
-			RACSignal *action;
-			if (attempt > SQRLShipItMaximumInstallationAttempts) {
-				action = [[[installer.abortInstallationCommand
-					execute:request]
-					initially:^{
-						NSLog(@"Too many attempts to install, aborting update");
-					}]
-					catch:^(NSError *error) {
-						NSLog(@"Error aborting installation: %@", error);
-
-						// Exit successfully so launchd doesn't restart us
-						// again.
-						return [RACSignal empty];
-					}];
-			} else {
-				action = [[[[installer.installUpdateCommand
-					execute:request]
-					initially:^{
-						BOOL freshInstall = (attempt == 1);
-						if (freshInstall) {
-							NSLog(@"Beginning installation");
-						} else {
-							NSLog(@"Resuming installation attempt %i", (int)attempt);
-						}
-					}]
-					doCompleted:^{
-						NSLog(@"Installation completed successfully");
-					}]
-					sqrl_addTransactionWithName:NSLocalizedString(@"Updating", nil) description:NSLocalizedString(@"%@ is being updated, and interrupting the process could corrupt the application", nil), request.targetBundleURL.path];
-			}
-
-			// Clear the installation attempts for a successful abort or
-			// install.
-			action = [action doCompleted:^{
-				clearInstallationAttempts(applicationIdentifier);
-			}];
-
-			if (request.launchAfterInstallation) {
-				// Launch regardless of whether installation succeeds or fails.
-				action = [[action
-					deliverOn:RACScheduler.mainThreadScheduler]
-					finally:^{
-						NSURL *bundleURL = request.targetBundleURL;
-						if (bundleURL == nil) {
-							NSLog(@"Missing target bundle URL, cannot launch application");
-							return;
-						}
-
-						NSError *error;
-						if (![NSWorkspace.sharedWorkspace launchApplicationAtURL:bundleURL options:NSWorkspaceLaunchDefault configuration:nil error:&error]) {
-							NSLog(@"Could not launch application at %@: %@", bundleURL, error);
-							return;
-						}
-
-						NSLog(@"Application launched at %@", bundleURL);
-					}];
-			}
-
-			return action;
-		}]
-		subscribeError:^(NSError *error) {
-			NSLog(@"Installation error: %@", error);
-			exit(EXIT_FAILURE);
-		} completed:^{
-			exit(EXIT_SUCCESS);
-		}];
-}
-
 int main(int argc, const char * argv[]) {
 	@autoreleasepool {
 		atexit_b(^{
@@ -152,13 +51,100 @@ int main(int argc, const char * argv[]) {
 			return EXIT_FAILURE;
 		}
 
-		char const *jobLabel = argv[1];
+		const char *jobLabel = argv[1];
 		SQRLDirectoryManager *directoryManager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:@(jobLabel)];
+		RACSignal *stateLocation = directoryManager.shipItStateURL;
 
-		installRequest([SQRLShipItRequest readUsingURL:directoryManager.shipItStateURL], directoryManager);
+		[[[[[[[SQRLShipItState
+			readUsingURL:stateLocation]
+			flattenMap:^(SQRLShipItState *state) {
+				return waitForTerminationIfNecessary(state);
+			}]
+			ignoreValues]
+			// Read the latest state, in case it was modified by the
+			// controlling application in the meantime.
+			concat:[SQRLShipItState readUsingURL:stateLocation]]
+			catch:^(NSError *error) {
+				NSLog(@"Error reading saved installer state: %@", error);
+
+				// Exit successfully so launchd doesn't restart us again.
+				return [RACSignal empty];
+			}]
+			flattenMap:^(SQRLShipItState *state) {
+				BOOL freshInstall = (state.installerState == SQRLInstallerStateNothingToDo);
+				SQRLInstaller *installer = [[SQRLInstaller alloc] initWithDirectoryManager:directoryManager];
+
+				NSUInteger attempt = (freshInstall ? 1 : state.installationStateAttempt + 1);
+				RACSignal *action;
+
+				if (attempt > SQRLShipItMaximumInstallationAttempts) {
+					action = [[RACSignal
+						defer:^{
+							NSLog(@"Too many attempts to install from state %i, aborting update", (int)state.installerState);
+
+							return [installer abortInstallationWithState:state];
+						}]
+						catch:^(NSError *error) {
+							NSLog(@"Error aborting installation: %@", error);
+
+							// Exit successfully so launchd doesn't restart us again.
+							return [RACSignal empty];
+						}];
+				} else {
+					action = [[[[RACSignal
+						defer:^{
+							if (freshInstall) {
+								NSLog(@"Beginning installation");
+								state.installerState = SQRLInstallerStateClearingQuarantine;
+							} else {
+								NSLog(@"Resuming installation from state %i", (int)state.installerState);
+							}
+
+							state.installationStateAttempt = attempt;
+
+							return [state writeUsingURL:stateLocation];
+						}]
+						concat:[installer installUpdateWithState:state]]
+						doCompleted:^{
+							NSLog(@"Installation completed successfully");
+						}]
+						sqrl_addTransactionWithName:NSLocalizedString(@"Updating", nil) description:NSLocalizedString(@"%@ is being updated, and interrupting the process could corrupt the application", nil), state.targetBundleURL.path];
+				}
+
+				if (state.relaunchAfterInstallation) {
+					// Relaunch regardless of whether installation succeeds or
+					// fails.
+					action = [[action
+						deliverOn:RACScheduler.mainThreadScheduler]
+						doFinished:^{
+							NSURL *bundleURL = state.targetBundleURL;
+							if (bundleURL == nil) {
+								NSLog(@"Missing target bundle URL, cannot relaunch application");
+								return;
+							}
+
+							NSError *error = nil;
+							if (![NSWorkspace.sharedWorkspace launchApplicationAtURL:bundleURL options:NSWorkspaceLaunchDefault configuration:nil error:&error]) {
+								NSLog(@"Could not relaunch application at %@: %@", bundleURL, error);
+								return;
+							}
+
+							NSLog(@"Application relaunched at %@", bundleURL);
+						}];
+				}
+
+				return action;
+			}]
+			subscribeError:^(NSError *error) {
+				NSLog(@"Installation error: %@", error);
+				exit(EXIT_FAILURE);
+			} completed:^{
+				exit(EXIT_SUCCESS);
+			}];
 
 		dispatch_main();
 	}
 
 	return EXIT_SUCCESS;
 }
+

Squirrel/Squirrel-Prefix.pch

@@ -0,0 +1,8 @@
+//
+// Prefix header for all source files of the 'Squirrel' target in the 'Squirrel' project
+//
+
+#ifdef __OBJC__
+	#import <Cocoa/Cocoa.h>
+    #import <SystemConfiguration/SystemConfiguration.h>
+#endif

Squirrel/Squirrel.h

@@ -6,14 +6,6 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Foundation/Foundation.h>
-
-//! Project version number for Squirrel.
-FOUNDATION_EXPORT double SquirrelVersionNumber;
-
-//! Project version string for Squirrel.
-FOUNDATION_EXPORT const unsigned char SquirrelVersionString[];
-
 #import <Squirrel/NSBundle+SQRLVersionExtensions.h>
 #import <Squirrel/NSProcessInfo+SQRLVersionExtensions.h>
 #import <Squirrel/SQRLDownloadedUpdate.h>

Squirrel/en.lproj/InfoPlist.strings

@@ -0,0 +1,2 @@
+/* Localized versions of Info.plist keys */
+

SquirrelTests/NSHTTPURLResponseExtensionsSpec.m

@@ -0,0 +1,23 @@
+//
+//  NSHTTPURLResponseExtensionsSpec.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 04/12/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "NSHTTPURLResponse+SQRLExtensions.h"
+
+SpecBegin(NSHTTPURLResponseExtensions)
+
+it(@"should perform case insensitive key look up", ^{
+	NSDictionary *headers = @{
+		@"ETag": @"foo",
+	};
+	NSHTTPURLResponse *response = [[NSHTTPURLResponse alloc] initWithURL:[NSURL URLWithString:@"http://localhost"] statusCode:200 HTTPVersion:(__bridge NSString *)kCFHTTPVersion1_1 headerFields:headers];
+
+	expect([response sqrl_valueForHTTPHeaderField:@"etag"]).to.equal(@"foo");
+	expect([response sqrl_valueForHTTPHeaderField:@"ETAG"]).to.equal(@"foo");
+});
+
+SpecEnd

SquirrelTests/NSProcessInfoExtensionsSpec.m

@@ -6,35 +6,30 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
-QuickSpecBegin(NSProcessInfoExtensions)
+SpecBegin(NSProcessInfoExtensions)
 
 describe(@"-sqrl_operatingSystemShortVersionString", ^{
 	__block NSString *versionString;
 
 	beforeEach(^{
 		versionString = NSProcessInfo.processInfo.sqrl_operatingSystemShortVersionString;
-		expect(versionString).notTo(beNil());
+		expect(versionString).notTo.beNil();
 	});
 
 	it(@"should follow major.minor.patch format", ^{
 		NSError *error = nil;
 		NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"^[0-9]+(\\.[0-9]+)*$" options:0 error:&error];
-		expect(regex).notTo(beNil());
-		expect(error).to(beNil());
+		expect(regex).notTo.beNil();
+		expect(error).to.beNil();
 
 		NSRange fullRange = NSMakeRange(0, versionString.length);
 		NSRange matchRange = [regex rangeOfFirstMatchInString:versionString options:0 range:fullRange];
-		expect(@(NSEqualRanges(matchRange, fullRange))).to(beTruthy());
+		expect(NSEqualRanges(matchRange, fullRange)).to.beTruthy();
 	});
 
 	it(@"should be numerically comparable", ^{
-		expect(@([@"10.6.9" compare:versionString options:NSNumericSearch])).to(equal(@(NSOrderedAscending)));
+		expect([@"10.6.9" compare:versionString options:NSNumericSearch]).to.equal(NSOrderedAscending);
 	});
 });
 
-QuickSpecEnd
+SpecEnd

SquirrelTests/SQRLCodeSignatureVerifierSpec.m

@@ -6,16 +6,9 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
 #import "SQRLCodeSignature.h"
 
-#import "QuickSpec+SQRLFixtures.h"
-
-QuickSpecBegin(SQRLCodeSignatureSpec)
+SpecBegin(SQRLCodeSignature)
 
 __block NSBundle *bundle;
 __block void (^corruptURL)(NSURL *URL);
@@ -24,26 +17,26 @@ beforeEach(^{
 	bundle = self.testApplicationBundle;
 
 	corruptURL = ^(NSURL *URL) {
-		expect(@([@"this bundle is corrupted, yo" writeToURL:bundle.executableURL atomically:YES encoding:NSUTF8StringEncoding error:NULL])).to(beTruthy());
+		expect([@"this bundle is corrupted, yo" writeToURL:bundle.executableURL atomically:YES encoding:NSUTF8StringEncoding error:NULL]).to.beTruthy();
 	};
 });
 
 it(@"should verify a valid bundle", ^{
 	NSError *error = nil;
 	BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-	expect(@(success)).to(beTruthy());
-	expect(error).to(beNil());
+	expect(success).to.beTruthy();
+	expect(error).to.beNil();
 });
 
 it(@"should fail to verify with different code signing requirements", ^{
 	NSError *error = nil;
-	SQRLCodeSignature *signature = [SQRLCodeSignature currentApplicationSignature:&error];
-	expect(signature).notTo(beNil());
-	expect(error).to(beNil());
+	SQRLCodeSignature *verifier = [SQRLCodeSignature currentApplicationSignature:&error];
+	expect(verifier).notTo.beNil();
+	expect(error).to.beNil();
 
-	BOOL success = [[signature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-	expect(@(success)).to(beFalsy());
-	expect(error).notTo(beNil());
+	BOOL success = [[verifier verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
+	expect(success).to.beFalsy();
+	expect(error).notTo.beNil();
 });
 
 describe(@"code signature changes", ^{
@@ -54,15 +47,15 @@ describe(@"code signature changes", ^{
 	});
 
 	it(@"should fail to verify a bundle with a missing code signature", ^{
-		expect(@([NSFileManager.defaultManager removeItemAtURL:codeSignatureURL error:NULL])).to(beTruthy());
+		expect([NSFileManager.defaultManager removeItemAtURL:codeSignatureURL error:NULL]).to.beTruthy();
 
 		NSError *error = nil;
 		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beFalsy());
+		expect(success).to.beFalsy();
 
-		expect(error).notTo(beNil());
-		expect(error.domain).to(equal(SQRLCodeSignatureErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLCodeSignatureErrorDidNotPass)));
+		expect(error).notTo.beNil();
+		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 
 	it(@"should fail to verify a bundle with a corrupt code signature", ^{
@@ -70,25 +63,25 @@ describe(@"code signature changes", ^{
 
 		NSError *error = nil;
 		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beFalsy());
+		expect(success).to.beFalsy();
 
-		expect(error).notTo(beNil());
-		expect(error.domain).to(equal(SQRLCodeSignatureErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLCodeSignatureErrorDidNotPass)));
+		expect(error).notTo.beNil();
+		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 });
 
 describe(@"main executable changes", ^{
 	it(@"should fail to verify a bundle with a missing executable", ^{
-		expect(@([NSFileManager.defaultManager removeItemAtURL:bundle.executableURL error:NULL])).to(beTruthy());
+		expect([NSFileManager.defaultManager removeItemAtURL:bundle.executableURL error:NULL]).to.beTruthy();
 
 		NSError *error = nil;
 		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beFalsy());
+		expect(success).to.beFalsy();
 
-		expect(error).notTo(beNil());
-		expect(error.domain).to(equal(SQRLCodeSignatureErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLCodeSignatureErrorCouldNotCreateStaticCode)));
+		expect(error).notTo.beNil();
+		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.code).to.equal(SQRLCodeSignatureErrorCouldNotCreateStaticCode);
 	});
 
 	it(@"should fail to verify a bundle with a corrupt executable", ^{
@@ -96,11 +89,11 @@ describe(@"main executable changes", ^{
 
 		NSError *error = nil;
 		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beFalsy());
+		expect(success).to.beFalsy();
 
-		expect(error).notTo(beNil());
-		expect(error.domain).to(equal(SQRLCodeSignatureErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLCodeSignatureErrorDidNotPass)));
+		expect(error).notTo.beNil();
+		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 });
 
@@ -109,19 +102,19 @@ describe(@"helper executable changes", ^{
 
 	beforeEach(^{
 		helperURL = [bundle URLForAuxiliaryExecutable:@"unused-helper"];
-		expect(helperURL).notTo(beNil());
+		expect(helperURL).notTo.beNil();
 	});
 
 	it(@"should fail to verify a bundle with a missing helper", ^{
-		expect(@([NSFileManager.defaultManager removeItemAtURL:helperURL error:NULL])).to(beTruthy());
+		expect([NSFileManager.defaultManager removeItemAtURL:helperURL error:NULL]).to.beTruthy();
 
 		NSError *error = nil;
 		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beFalsy());
+		expect(success).to.beFalsy();
 
-		expect(error).notTo(beNil());
-		expect(error.domain).to(equal(SQRLCodeSignatureErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLCodeSignatureErrorDidNotPass)));
+		expect(error).notTo.beNil();
+		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 
 	it(@"should fail to verify a bundle with a corrupt helper", ^{
@@ -129,11 +122,11 @@ describe(@"helper executable changes", ^{
 
 		NSError *error = nil;
 		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beFalsy());
+		expect(success).to.beFalsy();
 
-		expect(error).notTo(beNil());
-		expect(error.domain).to(equal(SQRLCodeSignatureErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLCodeSignatureErrorDidNotPass)));
+		expect(error).notTo.beNil();
+		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 });
 
@@ -142,19 +135,19 @@ describe(@"resource changes", ^{
 
 	beforeEach(^{
 		resourceURL = [bundle URLForResource:@"MainMenu" withExtension:@"nib"];
-		expect(resourceURL).notTo(beNil());
+		expect(resourceURL).notTo.beNil();
 	});
 
 	it(@"should fail to verify a bundle with a missing resource", ^{
-		expect(@([NSFileManager.defaultManager removeItemAtURL:resourceURL error:NULL])).to(beTruthy());
+		expect([NSFileManager.defaultManager removeItemAtURL:resourceURL error:NULL]).to.beTruthy();
 
 		NSError *error = nil;
 		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beFalsy());
+		expect(success).to.beFalsy();
 
-		expect(error).notTo(beNil());
-		expect(error.domain).to(equal(SQRLCodeSignatureErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLCodeSignatureErrorDidNotPass)));
+		expect(error).notTo.beNil();
+		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 
 	it(@"should fail to verify a bundle with a corrupt resource", ^{
@@ -162,11 +155,11 @@ describe(@"resource changes", ^{
 
 		NSError *error = nil;
 		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beFalsy());
+		expect(success).to.beFalsy();
 
-		expect(error).notTo(beNil());
-		expect(error.domain).to(equal(SQRLCodeSignatureErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLCodeSignatureErrorDidNotPass)));
+		expect(error).notTo.beNil();
+		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 });
 
@@ -178,15 +171,15 @@ describe(@"framework changes", ^{
 	});
 
 	it(@"should fail to verify a bundle with a missing framework", ^{
-		expect(@([NSFileManager.defaultManager removeItemAtURL:frameworkURL error:NULL])).to(beTruthy());
+		expect([NSFileManager.defaultManager removeItemAtURL:frameworkURL error:NULL]).to.beTruthy();
 
 		NSError *error = nil;
 		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beFalsy());
+		expect(success).to.beFalsy();
 
-		expect(error).notTo(beNil());
-		expect(error.domain).to(equal(SQRLCodeSignatureErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLCodeSignatureErrorDidNotPass)));
+		expect(error).notTo.beNil();
+		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 
 	it(@"should fail to verify a bundle with a corrupt framework", ^{
@@ -194,12 +187,12 @@ describe(@"framework changes", ^{
 
 		NSError *error = nil;
 		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:bundle.bundleURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beFalsy());
+		expect(success).to.beFalsy();
 
-		expect(error).notTo(beNil());
-		expect(error.domain).to(equal(SQRLCodeSignatureErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLCodeSignatureErrorDidNotPass)));
+		expect(error).notTo.beNil();
+		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 });
 
-QuickSpecEnd
+SpecEnd

SquirrelTests/SQRLDeepCodesignSpec.m

@@ -6,14 +6,7 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
-#import "QuickSpec+SQRLFixtures.h"
-
-QuickSpecBegin(SQRLDeepCodesign)
+SpecBegin(SQRLDeepCodesign)
 
 NSMutableDictionary * (^environmentSuitableForChildProcess)(void) = ^ {
 	// Remove environment variables that configure the Obj-C runtime
@@ -49,7 +42,7 @@ void (^resignTestApplicationPreserveEverythingButTheRequirements)(void) = ^{
 	[resignCodesignTask launch];
 	[resignCodesignTask waitUntilExit];
 
-	expect(@(resignCodesignTask.terminationStatus)).to(equal(@0));
+	expect(resignCodesignTask.terminationStatus).to.equal(0);
 };
 
 void (^deepCodesignTestApplication)(void) = ^{
@@ -61,9 +54,9 @@ void (^deepCodesignTestApplication)(void) = ^{
 	NSNumber *executable = nil;
 	NSError *executableError = nil;
 	BOOL getExecutable = [deepCodesignLocation getResourceValue:&executable forKey:NSURLIsExecutableKey error:&executableError];
-	expect(@(getExecutable)).to(beTruthy());
-	expect(@(executable.boolValue)).to(beTruthy());
-	expect(executableError).to(beNil());
+	expect(getExecutable).to.beTruthy();
+	expect(executable.boolValue).to.beTruthy();
+	expect(executableError).to.beNil();
 
 	NSTask *deepCodesignTask = [[NSTask alloc] init];
 	deepCodesignTask.launchPath = deepCodesignLocation.path;
@@ -82,7 +75,7 @@ void (^deepCodesignTestApplication)(void) = ^{
 	[deepCodesignTask launch];
 	[deepCodesignTask waitUntilExit];
 
-	expect(@(deepCodesignTask.terminationStatus)).to(equal(@0));
+	expect(deepCodesignTask.terminationStatus).to.equal(0);
 
 	/*
 		By signing test application's contents, which are covered by test
@@ -118,9 +111,9 @@ it(@"should deep sign the test application", ^{
 });
 
 xit(@"should deep verify after signing", ^{
-	expect(@(deepVerify())).to(beFalsy());
+	expect(deepVerify()).to.beFalsy();
 	deepCodesignTestApplication();
-	expect(@(deepVerify())).to(beTruthy());
+	expect(deepVerify()).to.beTruthy();
 });
 
-QuickSpecEnd
+SpecEnd

SquirrelTests/SQRLDirectoryManagerSpec.m

@@ -6,31 +6,26 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
 #import "SQRLDirectoryManager.h"
 
-QuickSpecBegin(SQRLDirectoryManagerSpec)
+SpecBegin(SQRLDirectoryManager)
 
 __block NSString *otestIdentifier;
 
 beforeEach(^{
-	otestIdentifier = NSProcessInfo.processInfo.environment[@"FORCE_APP_IDENTIFIER"];
-	expect(otestIdentifier).notTo(beNil());
+	otestIdentifier = NSRunningApplication.currentApplication.localizedName;
+	expect(otestIdentifier).notTo.beNil();
 });
 
 it(@"should initialize", ^{
 	SQRLDirectoryManager *manager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:otestIdentifier];
-	expect(manager).notTo(beNil());
+	expect(manager).notTo.beNil();
 });
 
 it(@"should create a manager for the current app", ^{
 	SQRLDirectoryManager *manager = SQRLDirectoryManager.currentApplicationManager;
-	expect(manager).notTo(beNil());
-	expect(manager).to(equal([[SQRLDirectoryManager alloc] initWithApplicationIdentifier:otestIdentifier]));
+	expect(manager).notTo.beNil();
+	expect(manager).to.equal([[SQRLDirectoryManager alloc] initWithApplicationIdentifier:otestIdentifier]);
 });
 
 it(@"should send an Application Support URL", ^{
@@ -38,12 +33,12 @@ it(@"should send an Application Support URL", ^{
 
 	NSError *error = nil;
 	NSURL *appSupportURL = [[manager applicationSupportURL] firstOrDefault:nil success:NULL error:&error];
-	expect(appSupportURL).notTo(beNil());
-	expect(error).to(beNil());
+	expect(appSupportURL).notTo.beNil();
+	expect(error).to.beNil();
 
 	__block BOOL directory = NO;
-	expect(@([NSFileManager.defaultManager fileExistsAtPath:appSupportURL.path isDirectory:&directory])).to(beTruthy());
-	expect(@(directory)).to(beTruthy());
+	expect([NSFileManager.defaultManager fileExistsAtPath:appSupportURL.path isDirectory:&directory]).to.beTruthy();
+	expect(directory).to.beTruthy();
 });
 
 it(@"should send a ShipIt state URL", ^{
@@ -51,8 +46,8 @@ it(@"should send a ShipIt state URL", ^{
 
 	NSError *error = nil;
 	NSURL *stateURL = [[manager shipItStateURL] firstOrDefault:nil success:NULL error:&error];
-	expect(stateURL).notTo(beNil());
-	expect(error).to(beNil());
+	expect(stateURL).notTo.beNil();
+	expect(error).to.beNil();
 });
 
-QuickSpecEnd
+SpecEnd

SquirrelTests/SQRLDownloadManagerSpec.m

@@ -0,0 +1,87 @@
+//
+//  SQRLDownloadControllerSpec.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 27/09/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "SQRLDownloadManager.h"
+#import "SQRLResumableDownload.h"
+#import "NSError+SQRLVerbosityExtensions.h"
+#import <ReactiveCocoa/ReactiveCocoa.h>
+
+SpecBegin(SQRLDownloadManager)
+
+__block SQRLDownloadManager *downloadManager = nil;
+
+beforeAll(^{
+	downloadManager = SQRLDownloadManager.defaultDownloadManager;
+
+	NSError *removeError = nil;
+	BOOL remove = [[downloadManager removeAllResumableDownloads] waitUntilCompleted:&removeError];
+	if (!remove) {
+		if ([removeError.domain isEqualToString:NSCocoaErrorDomain] && removeError.code == NSFileNoSuchFileError) return;
+		
+		NSLog(@"Couldn’t remove resumable downloads %@", removeError.sqrl_verboseDescription);
+	}
+});
+
+NSURL * (^newTestURL)() = ^ () {
+	return [[NSURL alloc] initWithScheme:@"http" host:@"localhost" path:[@"/" stringByAppendingString:NSProcessInfo.processInfo.globallyUniqueString]];
+};
+
+NSURL * (^newDownloadURL)() = ^ () {
+	NSError *error = nil;
+	SQRLResumableDownload *download = [[downloadManager downloadForRequest:[NSURLRequest requestWithURL:newTestURL()]] firstOrDefault:nil success:NULL error:&error];
+	expect(download).notTo.beNil();
+	expect(error).to.beNil();
+
+	NSURL *downloadURL = download.fileURL;
+	expect(downloadURL).notTo.beNil();
+
+	return downloadURL;
+};
+
+it(@"should return a file that doesn't exist yet for new URLs", ^{
+	NSURL *downloadURL = newDownloadURL();
+
+	BOOL exists = [NSFileManager.defaultManager fileExistsAtPath:downloadURL.path];
+	expect(exists).to.beFalsy();
+});
+
+it(@"should return a path in a writable directory for new URLs", ^{
+	NSURL *downloadURL = newDownloadURL();
+
+	BOOL writable = [NSFileManager.defaultManager isWritableFileAtPath:downloadURL.URLByDeletingLastPathComponent.path];
+	expect(writable).to.beTruthy();
+});
+
+it(@"should return the same path for the same URL", ^{
+	NSURL *testURL = newTestURL();
+
+	SQRLDownload *download1 = [[downloadManager downloadForRequest:[NSURLRequest requestWithURL:testURL]] first];
+	SQRLDownload *download2 = [[downloadManager downloadForRequest:[NSURLRequest requestWithURL:testURL]] first];
+	expect(download1).notTo.beNil();
+	expect(download1).to.equal(download2);
+});
+
+it(@"should remember a response", ^{
+	NSURLRequest *request = [NSURLRequest requestWithURL:newTestURL()];
+	NSHTTPURLResponse *response = [[NSHTTPURLResponse alloc] initWithURL:request.URL statusCode:200 HTTPVersion:(__bridge NSString *)kCFHTTPVersion1_1 headerFields:@{ @"ETag": NSProcessInfo.processInfo.globallyUniqueString }];
+
+	SQRLDownload *initialDownload = [[downloadManager downloadForRequest:request] first];
+
+	SQRLResumableDownload *newDownload = [[SQRLResumableDownload alloc] initWithRequest:request response:response fileURL:initialDownload.fileURL];
+	expect(newDownload).notTo.equal(initialDownload);
+
+	NSError *error = nil;
+	BOOL setNewDownload = [[downloadManager setDownload:newDownload forRequest:request] waitUntilCompleted:&error];
+	expect(setNewDownload).to.beTruthy();
+	expect(error).to.beNil();
+
+	SQRLResumableDownload *resumedDownload = [[downloadManager downloadForRequest:request] first];
+	expect(newDownload).to.equal(resumedDownload);
+});
+
+SpecEnd

SquirrelTests/SQRLDownloadedUpdateSpec.m

@@ -0,0 +1,40 @@
+//
+//  SQRLDownloadedUpdateSpec.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 04/12/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+SpecBegin(SQRLDownloadedUpdate)
+
+it(@"should serialise to JSON", ^{
+	NSError *error = nil;
+	SQRLUpdate *update = [SQRLUpdate modelWithDictionary:@{
+		@keypath(SQRLUpdate.new, updateURL) : [NSURL URLWithString:@"http://fake.domain/path"],
+	} error:&error];
+	expect(update).notTo.beNil();
+
+	NSURL *testApplicationURL = [self createTestApplicationUpdate];
+	NSBundle *testApplicationBundle = [NSBundle bundleWithURL:testApplicationURL];
+	expect(testApplicationBundle).notTo.beNil();
+
+	SQRLDownloadedUpdate *downloadedUpdate = [[SQRLDownloadedUpdate alloc] initWithUpdate:update bundle:testApplicationBundle];
+	expect(downloadedUpdate).notTo.beNil();
+
+	NSDictionary *JSONDictionary = [MTLJSONAdapter JSONDictionaryFromModel:downloadedUpdate];
+	expect(JSONDictionary).notTo.beNil();
+
+	NSData *JSONData = [NSJSONSerialization dataWithJSONObject:JSONDictionary options:0 error:&error];
+	expect(JSONData).notTo.beNil();
+	expect(error).to.beNil();
+
+	JSONDictionary = [NSJSONSerialization JSONObjectWithData:JSONData options:0 error:&error];
+	expect(JSONDictionary).notTo.beNil();
+
+	SQRLDownloadedUpdate *downloadedUpdate2 = [MTLJSONAdapter modelOfClass:SQRLDownloadedUpdate.class fromJSONDictionary:JSONDictionary error:&error];
+	expect(downloadedUpdate2).to.equal(downloadedUpdate);
+	expect(error).to.beNil();
+});
+
+SpecEnd

SquirrelTests/SQRLHTTPServer.h

@@ -0,0 +1,18 @@
+//
+//  SQRLHTTPServer.h
+//  Squirrel
+//
+//  Created by Keith Duncan on 03/12/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface SQRLHTTPServer : NSObject
+
+- (NSURL *)start:(NSError **)errorRef;
+- (void)invalidate;
+
+@property (copy, nonatomic) CFHTTPMessageRef (^responseBlock)(CFHTTPMessageRef request);
+
+@end

SquirrelTests/SQRLHTTPServer.m

@@ -0,0 +1,165 @@
+//
+//  SQRLHTTPServer.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 03/12/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "SQRLHTTPServer.h"
+
+#import <sys/socket.h>
+#import <netinet/in.h>
+
+@interface SQRLHTTPServer ()
+@property (assign, nonatomic) dispatch_source_t listenerSource;
+@property (strong, nonatomic) NSMutableArray *cleanupBlocks;
+@end
+
+@implementation SQRLHTTPServer
+
+- (id)init {
+	self = [super init];
+	if (self == nil) return nil;
+
+	_cleanupBlocks = [[NSMutableArray alloc] init];
+
+	return self;
+}
+
+- (void)dealloc {
+	[self invalidate];
+}
+
+- (NSURL *)start:(NSError **)errorRef {
+	NSParameterAssert(self.listenerSource == NULL);
+
+	int listenSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+
+	struct sockaddr_in listenAddress = {
+		.sin_len = sizeof(listenAddress),
+		.sin_family = AF_INET,
+		.sin_port = 0,
+		.sin_addr = {
+			.s_addr = htonl(INADDR_LOOPBACK),
+		},
+	};
+	int bindError = bind(listenSocket, (struct sockaddr const *)&listenAddress, listenAddress.sin_len);
+	if (bindError != 0) {
+		close(listenSocket);
+
+		if (errorRef != NULL) *errorRef = [NSError errorWithDomain:NSPOSIXErrorDomain code:bindError userInfo:nil];
+		return nil;
+	}
+
+	listen(listenSocket, 128);
+
+	dispatch_source_t source = dispatch_source_create(DISPATCH_SOURCE_TYPE_READ, listenSocket, 0, NULL);
+	dispatch_source_set_event_handler(source, ^{
+		int connectionSocket = accept(listenSocket, NULL, NULL);
+		// Wait to close the connection until after the test case is complete.
+		// We need NSURLConnection to timeout, closing the connection causes it
+		// to error immediately.
+		[self addCleanupBlock:^{
+			close(connectionSocket);
+		}];
+
+		CFHTTPMessageRef request = (__bridge CFHTTPMessageRef)CFBridgingRelease(CFHTTPMessageCreateEmpty(kCFAllocatorDefault, true));
+
+		while (1) {
+			uint8_t buffer;
+			ssize_t readLength = read(connectionSocket, &buffer, 1);
+			if (readLength < 0) {
+				return;
+			}
+
+			CFHTTPMessageAppendBytes(request, (UInt8 const *)&buffer, readLength);
+			if (!CFHTTPMessageIsHeaderComplete(request)) {
+				continue;
+			}
+
+			// Doesn't support reading requests with a body for simplicity
+			NSString *contentLength = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("Content-Length")));
+			if (contentLength != nil) {
+				return;
+			}
+
+			break;
+		}
+
+		NSLog(@"Received Request:");
+		NSLog(@"%@", [[NSString alloc] initWithData:CFBridgingRelease(CFHTTPMessageCopySerializedMessage(request)) encoding:NSASCIIStringEncoding]);
+
+		CFHTTPMessageRef response = self.responseBlock(request);
+		NSData *responseData = CFBridgingRelease(CFHTTPMessageCopySerializedMessage(response));
+
+		NSLog(@"Sending Response:");
+		NSLog(@"%@", [[NSString alloc] initWithData:responseData encoding:NSASCIIStringEncoding]);
+
+		size_t bufferLength = responseData.length;
+		uint8_t const *buffer = responseData.bytes;
+
+		while (1) {
+			ssize_t writeLength = write(connectionSocket, buffer, bufferLength);
+			if (writeLength < 0) {
+				return;
+			}
+
+			buffer += writeLength;
+			bufferLength -= writeLength;
+
+			if (bufferLength == 0) {
+				break;
+			}
+		}
+	});
+	dispatch_source_set_cancel_handler(source, ^{
+		close(listenSocket);
+	});
+	dispatch_resume(source);
+
+	struct sockaddr_storage localAddress = {};
+	socklen_t localAddressLength = sizeof(localAddress);
+	int localAddressError = getsockname(listenSocket, (struct sockaddr *)&localAddress, &localAddressLength);
+	if (localAddressError != 0) {
+		dispatch_release(source);
+
+		if (errorRef != NULL) *errorRef = [NSError errorWithDomain:NSPOSIXErrorDomain code:localAddressError userInfo:nil];
+		return nil;
+	}
+
+	self.listenerSource = source;
+
+	// IPv4 and IPv6 address transport layer port fields are at the same offset
+	// and are the same size
+	in_port_t port = ntohs(((struct sockaddr_in *)&localAddress)->sin_port);
+
+	return [NSURL URLWithString:[NSString stringWithFormat:@"http://localhost:%ld/", (unsigned long)port]];
+}
+
+- (void)invalidate {
+	dispatch_source_t listenerSource = self.listenerSource;
+	if (listenerSource == NULL) return;
+
+	dispatch_source_cancel(listenerSource);
+	dispatch_release(listenerSource);
+
+	self.listenerSource = NULL;
+
+	[self performCleanup];
+}
+
+- (void)addCleanupBlock:(void (^)(void))block {
+	[self.cleanupBlocks addObject:[block copy]];
+}
+
+- (void)performCleanup {
+	NSArray *blocks = [self.cleanupBlocks copy];
+	[self.cleanupBlocks removeAllObjects];
+
+	for (void (^currentBlock)(void) in blocks) {
+		currentBlock();
+	}
+}
+
+@end

SquirrelTests/SQRLInstallerSpec.m

@@ -6,32 +6,13 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
 #import "SQRLCodeSignature.h"
 #import "SQRLDirectoryManager.h"
-#import "SQRLInstaller+Private.h"
-#import "SQRLInstallerOwnedBundle.h"
-#import "SQRLShipItRequest.h"
+#import "SQRLInstaller.h"
+#import "SQRLShipItLauncher.h"
+#import "SQRLShipItState.h"
 
-#import "QuickSpec+SQRLFixtures.h"
-
-QuickSpecBegin(SQRLInstallerSpec)
-
-mode_t (^modeOfURL)(NSURL *) = ^ mode_t (NSURL *fileURL) {
-	NSFileSecurity *fileSecurity = nil;
-	BOOL success = [fileURL getResourceValue:&fileSecurity forKey:NSURLFileSecurityKey error:NULL];
-	expect(@(success)).to(beTruthy());
-	expect(fileSecurity).notTo(beNil());
-
-	__block mode_t mode;
-	expect(@(CFFileSecurityGetMode((__bridge CFFileSecurityRef)fileSecurity, &mode))).to(beTruthy());
-
-	return mode & (S_IRWXU | S_IRWXG | S_IRWXO);
-};
+SpecBegin(SQRLInstaller)
 
 __block NSURL *updateURL;
 
@@ -39,148 +20,127 @@ beforeEach(^{
 	updateURL = [self createTestApplicationUpdate];
 });
 
-it(@"should install an update using ShipIt", ^{
-	SQRLShipItRequest *request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:updateURL targetBundleURL:self.testApplicationURL bundleIdentifier:nil launchAfterInstallation:NO];
+it(@"should install an update", ^{
+	SQRLShipItState *state = [[SQRLShipItState alloc] initWithTargetBundleURL:self.testApplicationURL updateBundleURL:updateURL bundleIdentifier:nil codeSignature:self.testApplicationSignature];
+	expect([[state writeUsingURL:self.shipItDirectoryManager.shipItStateURL] waitUntilCompleted:NULL]).to.beTruthy();
 
-	[self installWithRequest:request remote:YES];
+	[self launchShipIt];
 
-	expect(self.testApplicationBundleVersion).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
-});
-
-it(@"should install an update in process", ^{
-	SQRLShipItRequest *request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:updateURL targetBundleURL:self.testApplicationURL bundleIdentifier:nil launchAfterInstallation:NO];
-
-	[self installWithRequest:request remote:NO];
-
-	expect(self.testApplicationBundleVersion).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
+	expect(self.testApplicationBundleVersion).will.equal(SQRLTestApplicationUpdatedShortVersionString);
 });
 
 it(@"should install an update and relaunch", ^{
 	NSString *bundleIdentifier = @"com.github.Squirrel.TestApplication";
 	NSArray *apps = [NSRunningApplication runningApplicationsWithBundleIdentifier:bundleIdentifier];
-	expect(@(apps.count)).to(equal(@0));
+	expect(apps.count).to.equal(0);
 
-	SQRLShipItRequest *request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:updateURL targetBundleURL:self.testApplicationURL bundleIdentifier:nil launchAfterInstallation:YES];
+	SQRLShipItState *state = [[SQRLShipItState alloc] initWithTargetBundleURL:self.testApplicationURL updateBundleURL:updateURL bundleIdentifier:nil codeSignature:self.testApplicationSignature];
+	state.relaunchAfterInstallation = YES;
+	expect([[state writeUsingURL:self.shipItDirectoryManager.shipItStateURL] waitUntilCompleted:NULL]).to.beTruthy();
 
-	[self installWithRequest:request remote:YES];
+	[self launchShipIt];
 
-	expect(self.testApplicationBundleVersion).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
-	expect(@([NSRunningApplication runningApplicationsWithBundleIdentifier:bundleIdentifier].count)).toEventually(equal(@1));
+	expect(self.testApplicationBundleVersion).will.equal(SQRLTestApplicationUpdatedShortVersionString);
+	expect([NSRunningApplication runningApplicationsWithBundleIdentifier:bundleIdentifier].count).will.equal(1);
 });
 
 it(@"should install an update from another volume", ^{
 	NSURL *diskImageURL = [self createAndMountDiskImageNamed:@"TestApplication 2.1" fromDirectory:updateURL.URLByDeletingLastPathComponent];
 	updateURL = [diskImageURL URLByAppendingPathComponent:updateURL.lastPathComponent];
 
-	SQRLShipItRequest *request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:updateURL targetBundleURL:self.testApplicationURL bundleIdentifier:nil launchAfterInstallation:NO];
+	SQRLShipItState *state = [[SQRLShipItState alloc] initWithTargetBundleURL:self.testApplicationURL updateBundleURL:updateURL bundleIdentifier:nil codeSignature:self.testApplicationSignature];
+	expect([[state writeUsingURL:self.shipItDirectoryManager.shipItStateURL] waitUntilCompleted:NULL]).to.beTruthy();
 
-	[self installWithRequest:request remote:YES];
+	[self launchShipIt];
 
-	expect(self.testApplicationBundleVersion).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
+	expect(self.testApplicationBundleVersion).will.equal(SQRLTestApplicationUpdatedShortVersionString);
 });
 
 it(@"should install an update to another volume", ^{
 	NSURL *diskImageURL = [self createAndMountDiskImageNamed:@"TestApplication" fromDirectory:self.testApplicationURL.URLByDeletingLastPathComponent];
 	NSURL *targetURL = [diskImageURL URLByAppendingPathComponent:self.testApplicationURL.lastPathComponent];
 
-	SQRLShipItRequest *request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:updateURL targetBundleURL:targetURL bundleIdentifier:nil launchAfterInstallation:NO];
+	SQRLShipItState *state = [[SQRLShipItState alloc] initWithTargetBundleURL:targetURL updateBundleURL:updateURL bundleIdentifier:nil codeSignature:self.testApplicationSignature];
+	expect([[state writeUsingURL:self.shipItDirectoryManager.shipItStateURL] waitUntilCompleted:NULL]).to.beTruthy();
 
-	[self installWithRequest:request remote:YES];
+	[self launchShipIt];
 
 	NSURL *plistURL = [targetURL URLByAppendingPathComponent:@"Contents/Info.plist"];
-	expect([NSDictionary dictionaryWithContentsOfURL:plistURL][SQRLBundleShortVersionStringKey]).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
+	expect([NSDictionary dictionaryWithContentsOfURL:plistURL][SQRLBundleShortVersionStringKey]).will.equal(SQRLTestApplicationUpdatedShortVersionString);
 });
 
-describe(@"with backup restoration", ^{
-	__block NSURL *targetURL;
+it(@"should install an update in process", ^{
+	SQRLShipItState *state = [[SQRLShipItState alloc] initWithTargetBundleURL:self.testApplicationURL updateBundleURL:updateURL bundleIdentifier:nil codeSignature:self.testApplicationSignature];
+	state.installerState = SQRLInstallerStateClearingQuarantine;
 
-	beforeEach(^{
-		targetURL = self.testApplicationURL;
+	SQRLInstaller *installer = [[SQRLInstaller alloc] initWithDirectoryManager:SQRLDirectoryManager.currentApplicationManager];
+	expect(installer).notTo.beNil();
 
-		NSURL *copiedTargetURL = [self.temporaryDirectoryURL URLByAppendingPathComponent:@"TestApplication Target.app"];
-		expect(@([NSFileManager.defaultManager moveItemAtURL:targetURL toURL:copiedTargetURL error:NULL])).to(beTruthy());
-
-		SQRLCodeSignature *codeSignature = self.testApplicationSignature;
-
-		SQRLInstallerOwnedBundle *ownedBundle = [[SQRLInstallerOwnedBundle alloc] initWithOriginalURL:targetURL temporaryURL:copiedTargetURL codeSignature:codeSignature];
-		NSData *ownedBundleArchive = [NSKeyedArchiver archivedDataWithRootObject:ownedBundle];
-		expect(ownedBundleArchive).notTo(beNil());
-
-		// Set up ShipIt's preferences like it paused in the middle of an
-		// installation.
-		NSString *applicationIdentifier = self.shipItDirectoryManager.applicationIdentifier;
-
-		CFPreferencesSetValue((__bridge CFStringRef)SQRLShipItInstallationAttemptsKey, (__bridge CFPropertyListRef)@(4), (__bridge CFStringRef)applicationIdentifier, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost);
-		CFPreferencesSetValue((__bridge CFStringRef)SQRLInstallerOwnedBundleKey, (__bridge CFDataRef)ownedBundleArchive, (__bridge CFStringRef)applicationIdentifier, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost);
-
-		BOOL synchronized = CFPreferencesSynchronize((__bridge CFStringRef)applicationIdentifier, kCFPreferencesCurrentUser, kCFPreferencesCurrentHost);
-		expect(@(synchronized)).to(beTruthy());
-	});
-
-	it(@"should not install an update after too many attempts", ^{
-		SQRLShipItRequest *request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:updateURL targetBundleURL:targetURL bundleIdentifier:nil launchAfterInstallation:NO];
-		[self installWithRequest:request remote:YES];
-
-		__block NSError *error;
-		expect(@([[self.testApplicationSignature verifyBundleAtURL:targetURL] waitUntilCompleted:&error])).toEventually(beTruthy());
-		expect(error).to(beNil());
-
-		expect(self.testApplicationBundleVersion).to(equal(SQRLTestApplicationOriginalShortVersionString));
-	});
-
-	it(@"should relaunch even after failing to install an update", ^{
-		SQRLShipItRequest *request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:updateURL targetBundleURL:targetURL bundleIdentifier:nil launchAfterInstallation:YES];
-		[self installWithRequest:request remote:YES];
-
-		expect(@([NSRunningApplication runningApplicationsWithBundleIdentifier:@"com.github.Squirrel.TestApplication"].count)).toEventually(equal(@1));
-		
-		__block NSError *error;
-		expect(@([[self.testApplicationSignature verifyBundleAtURL:targetURL] waitUntilCompleted:&error])).to(beTruthy());
-		expect(error).to(beNil());
-
-		expect(self.testApplicationBundleVersion).to(equal(SQRLTestApplicationOriginalShortVersionString));
-	});
+	NSError *installError = nil;
+	BOOL install = [[installer installUpdateWithState:state] asynchronouslyWaitUntilCompleted:&installError];
+	expect(install).to.beTruthy();
+	expect(installError).to.beNil();
 });
 
-it(@"should disallow writing the updated application except by the owner", ^{
-	NSString *command = [NSString stringWithFormat:@"chmod -R 0777 '%@'", updateURL.path];
-	expect(@(system(command.UTF8String))).to(equal(@0));
+it(@"should not install an update after too many attempts", ^{
+	NSURL *targetURL = self.testApplicationURL;
+	NSURL *backupURL = [self.temporaryDirectoryURL URLByAppendingPathComponent:@"TestApplication.app.bak"];
+	expect([NSFileManager.defaultManager moveItemAtURL:targetURL toURL:backupURL error:NULL]).to.beTruthy();
 
-	expect(@(modeOfURL(updateURL))).to(equal(@0777));
-	expect(@(modeOfURL([updateURL URLByAppendingPathComponent:@"Contents/MacOS/TestApplication"]))).to(equal(@0777));
+	SQRLShipItState *state = [[SQRLShipItState alloc] initWithTargetBundleURL:targetURL updateBundleURL:updateURL bundleIdentifier:nil codeSignature:self.testApplicationSignature];
+	state.backupBundleURL = backupURL;
+	state.installerState = SQRLInstallerStateInstalling;
+	state.installationStateAttempt = 4;
+	expect([[state writeUsingURL:self.shipItDirectoryManager.shipItStateURL] waitUntilCompleted:NULL]).to.beTruthy();
 
-	SQRLShipItRequest *request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:updateURL targetBundleURL:self.testApplicationURL bundleIdentifier:nil launchAfterInstallation:NO];
+	[self launchShipIt];
 
-	[self installWithRequest:request remote:YES];
+	// No update should've been installed, and the application should be
+	// restored from the backup.
+	__block NSError *error = nil;
+	expect([[self.testApplicationSignature verifyBundleAtURL:targetURL] waitUntilCompleted:&error]).will.beTruthy();
+	expect(error).to.beNil();
 
-	expect(self.testApplicationBundleVersion).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
+	expect(self.testApplicationBundleVersion).to.equal(SQRLTestApplicationOriginalShortVersionString);
+});
 
-	expect(@(modeOfURL(self.testApplicationURL))).to(equal(@0755));
-	expect(@(modeOfURL([self.testApplicationURL URLByAppendingPathComponent:@"Contents/MacOS/TestApplication"]))).to(equal(@0755));
+it(@"should relaunch even after failing to install an update", ^{
+	NSURL *targetURL = self.testApplicationURL;
+	NSURL *backupURL = [self.temporaryDirectoryURL URLByAppendingPathComponent:@"TestApplication.app.bak"];
+	expect([NSFileManager.defaultManager moveItemAtURL:targetURL toURL:backupURL error:NULL]).to.beTruthy();
+
+	SQRLShipItState *state = [[SQRLShipItState alloc] initWithTargetBundleURL:targetURL updateBundleURL:updateURL bundleIdentifier:nil codeSignature:self.testApplicationSignature];
+	state.backupBundleURL = backupURL;
+	state.installerState = SQRLInstallerStateInstalling;
+	state.installationStateAttempt = 4;
+	state.relaunchAfterInstallation = YES;
+	expect([[state writeUsingURL:self.shipItDirectoryManager.shipItStateURL] waitUntilCompleted:NULL]).to.beTruthy();
+
+	[self launchShipIt];
+
+	__block NSError *error = nil;
+	expect([[self.testApplicationSignature verifyBundleAtURL:targetURL] waitUntilCompleted:&error]).will.beTruthy();
+	expect(error).to.beNil();
+
+	expect([NSRunningApplication runningApplicationsWithBundleIdentifier:@"com.github.Squirrel.TestApplication"].count).will.equal(1);
+	expect(self.testApplicationBundleVersion).to.equal(SQRLTestApplicationOriginalShortVersionString);
 });
 
 describe(@"signal handling", ^{
 	__block NSURL *targetURL;
 
-	void (^verifyUpdate)(void) = ^{
-		// Wait up to the launchd throttle interval, then verify that ShipIt
-		// relaunched and finished installing the update.
-		expect(self.testApplicationBundleVersion).withTimeout(5).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
-
-		NSError *error;
-		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:targetURL] waitUntilCompleted:&error];
-		expect(@(success)).to(beTruthy());
-		expect(error).to(beNil());
-	};
-
 	beforeEach(^{
 		// Copied so that we don't recreate the TestApplication bundle by
 		// accessing the property.
 		targetURL = self.testApplicationURL;
 
-		SQRLShipItRequest *request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:updateURL targetBundleURL:self.testApplicationURL bundleIdentifier:nil launchAfterInstallation:NO];
+		SQRLShipItState *state = [[SQRLShipItState alloc] initWithTargetBundleURL:self.testApplicationURL updateBundleURL:updateURL bundleIdentifier:nil codeSignature:self.testApplicationSignature];
+		expect([[state writeUsingURL:self.shipItDirectoryManager.shipItStateURL] waitUntilCompleted:NULL]).to.beTruthy();
 
-		[self installWithRequest:request remote:YES];
+		[self launchShipIt];
+
+		// Wait until ShipIt has transitioned by at least one state.
+		expect([[[SQRLShipItState readUsingURL:self.shipItDirectoryManager.shipItStateURL] asynchronousFirstOrDefault:nil success:NULL error:NULL] installerState]).willNot.equal(SQRLInstallerStateNothingToDo);
 
 		// Apply a random delay before sending the termination signal, to
 		// fuzz out race conditions.
@@ -188,42 +148,45 @@ describe(@"signal handling", ^{
 		[NSThread sleepForTimeInterval:delay];
 	});
 
+	afterEach(^{
+		// Wait up to the launchd throttle interval, then verify that ShipIt
+		// relaunched and finished installing the update.
+		Expecta.asynchronousTestTimeout = 5;
+		expect(self.testApplicationBundleVersion).will.equal(SQRLTestApplicationUpdatedShortVersionString);
+
+		NSError *error = nil;
+		BOOL success = [[self.testApplicationSignature verifyBundleAtURL:targetURL] waitUntilCompleted:&error];
+		expect(success).to.beTruthy();
+		expect(error).to.beNil();
+	});
+
 	it(@"should handle SIGHUP", ^{
 		system("killall -HUP ShipIt");
-		verifyUpdate();
 	});
 
 	it(@"should handle SIGTERM", ^{
 		system("killall -TERM ShipIt");
-		verifyUpdate();
 	});
 
 	it(@"should handle SIGINT", ^{
 		system("killall -INT ShipIt");
-		verifyUpdate();
 	});
 
 	it(@"should handle SIGQUIT", ^{
 		system("killall -QUIT ShipIt");
-		verifyUpdate();
 	});
 
 	it(@"should handle SIGKILL", ^{
 		// SIGKILL is unique in that it'll always terminate ShipIt, so send it
-		// a couple times to really test resumption.
-		//
-		// Two SIGKILL signals means that it'll be launched three times (which
-		// matches the maximum number of attempts per state).
-		for (int i = 0; i < 2; i++) {
+		// a few times to really test resumption.
+		for (int i = 0; i < 3; i++) {
 			system("killall -KILL ShipIt");
 
 			// Wait at least for the launchd throttle interval.
 			NSTimeInterval delay = 2 + (arc4random_uniform(100) / 1000.0);
 			[NSThread sleepForTimeInterval:delay];
 		}
-
-		verifyUpdate();
 	});
 });
 
-QuickSpecEnd
+SpecEnd

SquirrelTests/SQRLShipItRequestSpec.m

@@ -1,86 +0,0 @@
-//
-//  SQRLShipItStateSpec.m
-//  Squirrel
-//
-//  Created by Justin Spahr-Summers on 2013-10-09.
-//  Copyright (c) 2013 GitHub. All rights reserved.
-//
-
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
-#import "SQRLDirectoryManager.h"
-#import "SQRLShipItRequest.h"
-
-#import "QuickSpec+SQRLFixtures.h"
-
-QuickSpecBegin(SQRLShipItRequestSpec)
-
-__block SQRLDirectoryManager *directoryManager;
-__block SQRLShipItRequest *request;
-
-beforeEach(^{
-	directoryManager = SQRLDirectoryManager.currentApplicationManager;
-
-	NSURL *updateURL = [self createTestApplicationUpdate];
-	request = [[SQRLShipItRequest alloc] initWithUpdateBundleURL:updateURL targetBundleURL:self.testApplicationURL bundleIdentifier:nil launchAfterInstallation:NO];
-	expect(request).notTo(beNil());
-
-	expect(request.targetBundleURL).to(equal(self.testApplicationURL));
-	expect(request.updateBundleURL).to(equal(updateURL));
-	expect(request.bundleIdentifier).to(beNil());
-	expect(@(request.launchAfterInstallation)).to(beFalsy());
-});
-
-afterEach(^{
-	NSURL *stateURL = [[directoryManager shipItStateURL] first];
-	expect(stateURL).notTo(beNil());
-
-	[NSFileManager.defaultManager removeItemAtURL:stateURL error:NULL];
-});
-
-it(@"should copy", ^{
-	SQRLShipItRequest *requestCopy = [request copy];
-	expect(requestCopy).to(equal(request));
-	expect(requestCopy).notTo(beIdenticalTo(request));
-});
-
-it(@"should fail to read state when no file exists yet", ^{
-	NSError *error;
-	BOOL success = [[SQRLShipItRequest readUsingURL:directoryManager.shipItStateURL] waitUntilCompleted:&error];
-	expect(@(success)).to(beFalsy());
-	expect(error).notTo(beNil());
-});
-
-it(@"should write and read state to disk", ^{
-	NSError *error;
-	BOOL success = [[request writeUsingURL:directoryManager.shipItStateURL] waitUntilCompleted:&error];
-	expect(@(success)).to(beTruthy());
-	expect(error).to(beNil());
-
-	SQRLShipItRequest *readRequest = [[SQRLShipItRequest readUsingURL:directoryManager.shipItStateURL] firstOrDefault:nil success:&success error:&error];
-	expect(@(success)).to(beTruthy());
-	expect(error).to(beNil());
-
-	expect(readRequest).to(equal(request));
-});
-
-it(@"should fail gracefully with archives encoding a different class", ^{
-	NSURL *archiveLocation = [self.temporaryDirectoryURL URLByAppendingPathComponent:@"archive"];
-
-	NSError *error;
-	BOOL write = [[NSKeyedArchiver archivedDataWithRootObject:@"rogue object"] writeToURL:archiveLocation atomically:YES];
-	expect(@(write)).to(beTruthy());
-	expect(error).to(beNil());
-
-	BOOL success = NO;
-	SQRLShipItRequest *request = [[SQRLShipItRequest readUsingURL:[RACSignal return:archiveLocation]] firstOrDefault:nil success:&success error:&error];
-	expect(request).to(beNil());
-	expect(@(success)).to(beFalsy());
-	expect(error.domain).to(equal(SQRLShipItRequestErrorDomain));
-	expect(@(error.code)).to(equal(@(SQRLShipItRequestErrorUnarchiving)));
-});
-
-QuickSpecEnd

SquirrelTests/SQRLShipItStateSpec.m

@@ -0,0 +1,63 @@
+//
+//  SQRLShipItStateSpec.m
+//  Squirrel
+//
+//  Created by Justin Spahr-Summers on 2013-10-09.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "SQRLDirectoryManager.h"
+#import "SQRLShipItState.h"
+
+SpecBegin(SQRLShipItState)
+
+__block SQRLDirectoryManager *directoryManager;
+__block SQRLShipItState *state;
+
+beforeEach(^{
+	directoryManager = SQRLDirectoryManager.currentApplicationManager;
+
+	NSURL *updateURL = [self createTestApplicationUpdate];
+	state = [[SQRLShipItState alloc] initWithTargetBundleURL:self.testApplicationURL updateBundleURL:updateURL bundleIdentifier:nil codeSignature:self.testApplicationSignature];
+	expect(state).notTo.beNil();
+
+	expect(state.targetBundleURL).to.equal(self.testApplicationURL);
+	expect(state.updateBundleURL).to.equal(updateURL);
+	expect(state.bundleIdentifier).to.beNil();
+	expect(state.codeSignature).to.equal(self.testApplicationSignature);
+});
+
+afterEach(^{
+	NSURL *stateURL = [[directoryManager shipItStateURL] firstOrDefault:nil success:NULL error:NULL];
+	expect(stateURL).notTo.beNil();
+	
+	[NSFileManager.defaultManager removeItemAtURL:stateURL error:NULL];
+});
+
+it(@"should copy", ^{
+	SQRLShipItState *stateCopy = [state copy];
+	expect(stateCopy).to.equal(state);
+	expect(stateCopy).notTo.beIdenticalTo(state);
+});
+
+it(@"should fail to read state when no file exists yet", ^{
+	NSError *error = nil;
+	BOOL success = [[SQRLShipItState readUsingURL:directoryManager.shipItStateURL] waitUntilCompleted:&error];
+	expect(success).to.beFalsy();
+	expect(error).notTo.beNil();
+});
+
+it(@"should write and read state", ^{
+	NSError *error = nil;
+	BOOL success = [[state writeUsingURL:directoryManager.shipItStateURL] waitUntilCompleted:&error];
+	expect(success).to.beTruthy();
+	expect(error).to.beNil();
+
+	SQRLShipItState *readState = [[SQRLShipItState readUsingURL:directoryManager.shipItStateURL] firstOrDefault:nil success:&success error:&error];
+	expect(success).to.beTruthy();
+	expect(error).to.beNil();
+
+	expect(readState).to.equal(state);
+});
+
+SpecEnd

SquirrelTests/SQRLTerminationListenerSpec.m

@@ -6,22 +6,15 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
 #import "SQRLTerminationListener.h"
 
-#import "QuickSpec+SQRLFixtures.h"
-
-QuickSpecBegin(SQRLTerminationListenerSpec)
+SpecBegin(SQRLTerminationListener)
 
 __block SQRLTerminationListener *listener;
 
 beforeEach(^{
 	listener = [[SQRLTerminationListener alloc] initWithURL:self.testApplicationURL bundleIdentifier:self.testApplicationBundle.bundleIdentifier];
-	expect(listener).notTo(beNil());
+	expect(listener).notTo.beNil();
 });
 
 it(@"should complete immediately when the app is not running", ^{
@@ -30,7 +23,7 @@ it(@"should complete immediately when the app is not running", ^{
 		completed = YES;
 	}];
 
-	expect(@(completed)).to(beTruthy());
+	expect(completed).to.beTruthy();
 });
 
 it(@"should wait until one instance terminates", ^{
@@ -44,12 +37,12 @@ it(@"should wait until one instance terminates", ^{
 		completed = YES;
 	}];
 
-	expect(observedApp).toEventually(equal(app));
-	expect(@(completed)).to(beFalsy());
+	expect(observedApp).will.equal(app);
+	expect(completed).to.beFalsy();
 
 	[app forceTerminate];
-	expect(@(app.terminated)).toEventually(beTruthy());
-	expect(@(completed)).toEventually(beTruthy());
+	expect(app.terminated).will.beTruthy();
+	expect(completed).will.beTruthy();
 });
 
 it(@"should wait until multiple instances terminate", ^{
@@ -61,15 +54,15 @@ it(@"should wait until multiple instances terminate", ^{
 		completed = YES;
 	}];
 
-	expect(@(completed)).to(beFalsy());
+	expect(completed).to.beFalsy();
 
 	[app1 forceTerminate];
-	expect(@(app1.terminated)).toEventually(beTruthy());
-	expect(@(completed)).to(beFalsy());
+	expect(app1.terminated).will.beTruthy();
+	expect(completed).to.beFalsy();
 
 	[app2 forceTerminate];
-	expect(@(app2.terminated)).toEventually(beTruthy());
-	expect(@(completed)).toEventually(beTruthy());
+	expect(app2.terminated).will.beTruthy();
+	expect(completed).will.beTruthy();
 });
 
-QuickSpecEnd
+SpecEnd

SquirrelTests/SQRLTestCase.h

@@ -1,16 +1,11 @@
 //
-//  QuickSpec+SQRLFixtures.h
+//  SQRLTestCase.h
 //  Squirrel
 //
 //  Created by Justin Spahr-Summers on 2013-08-06.
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
 // The short version string for the `testApplicationBundle`.
 extern NSString * const SQRLTestApplicationOriginalShortVersionString;
 
@@ -23,9 +18,8 @@ extern NSString * const SQRLBundleShortVersionStringKey;
 
 @class SQRLCodeSignature;
 @class SQRLDirectoryManager;
-@class SQRLShipItRequest;
 
-@interface QuickSpec (SQRLFixtures)
+@interface SQRLTestCase : SPTSenTestCase
 
 // A URL to a temporary directory tests can use.
 //
@@ -51,6 +45,10 @@ extern NSString * const SQRLBundleShortVersionStringKey;
 // A code signature with requirements from TestApplication.app.
 @property (nonatomic, strong, readonly) SQRLCodeSignature *testApplicationSignature;
 
+// A serialized `SecRequirementRef` representing the requirements from
+// TestApplication.app.
+@property (nonatomic, copy, readonly) NSData *testApplicationCodeSigningRequirementData;
+
 // A directory manager for finding URLs that apply to ShipIt.
 @property (nonatomic, strong, readonly) SQRLDirectoryManager *shipItDirectoryManager;
 
@@ -76,8 +74,8 @@ extern NSString * const SQRLBundleShortVersionStringKey;
 // deleted at the end of the example.
 - (NSURL *)createTestApplicationUpdate;
 
-// Runs the installer in process or submits ShipIt's launchd job to start it up.
-- (void)installWithRequest:(SQRLShipItRequest *)request remote:(BOOL)remote;
+// Submits ShipIt's launchd job to start it up.
+- (void)launchShipIt;
 
 // Creates a disk image, then mounts it.
 //

SquirrelTests/SQRLTestCase.m

@@ -1,20 +1,16 @@
 //
-//  QuickSpec+SQRLFixtures.m
+//  SQRLTestCase.m
 //  Squirrel
 //
 //  Created by Justin Spahr-Summers on 2013-08-06.
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import "QuickSpec+SQRLFixtures.h"
-
+#import "SQRLTestCase.h"
 #import "SQRLCodeSignature.h"
 #import "SQRLDirectoryManager.h"
-#import "SQRLInstaller.h"
 #import "SQRLShipItLauncher.h"
-#import "SQRLShipItRequest.h"
 #import <ServiceManagement/ServiceManagement.h>
-#import <objc/runtime.h>
 
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Warc-retain-cycles"
@@ -43,9 +39,105 @@ static void SQRLSignalHandler(int sig) {
 	abort();
 }
 
+@interface SQRLTestCase ()
+
+// An array of dispatch_block_t values, for performing cleanup after the current
+// example finishes.
+//
+// This array will be emptied between each example.
+@property (nonatomic, strong, readonly) NSMutableArray *exampleCleanupBlocks;
+
+// The URL to the temporary directory which contains `temporaryDirectoryURL` and
+// all copied test data.
+@property (nonatomic, copy, readonly) NSURL *baseTemporaryDirectoryURL;
+
 // Returns an _unlaunched_ task that will follow log files at the given paths,
 // then pipe that output through this process.
-static NSTask *SQRLTailTaskWithPaths(RACSequence *paths) {
++ (NSTask *)tailTaskWithPaths:(RACSignal *)paths;
+
+@end
+
+@implementation SQRLTestCase
+
+#pragma mark Properties
+
+@synthesize baseTemporaryDirectoryURL = _baseTemporaryDirectoryURL;
+
+#pragma mark Lifecycle
+
++ (void)load {
+	NSURL *appSupportURL = [NSFileManager.defaultManager URLForDirectory:NSApplicationSupportDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:YES error:NULL];
+	NSAssert(appSupportURL != nil, @"Could not find Application Support folder");
+
+	NSArray *folders = @[
+		@"com.github.Squirrel.TestApplication.ShipIt",
+		@"otest.ShipIt",
+		@"otest-x86_64.ShipIt",
+	];
+
+	RACSignal *logLocations = [[[[folders.rac_signal
+		flattenMap:^(NSString *folder) {
+			return [folder stringsByAppendingPaths:@[
+				@"ShipIt_stdout.log",
+				@"ShipIt_stderr.log",
+			]].rac_signal;
+		}]
+		map:^(NSString *path) {
+			return [appSupportURL URLByAppendingPathComponent:path];
+		}]
+		doNext:^(NSURL *location) {
+			[[NSData data] writeToURL:location atomically:YES];
+		}]
+		map:^(NSURL *location) {
+			return location.path;
+		}];
+
+	NSTask *readShipIt = [self tailTaskWithPaths:logLocations];
+	[readShipIt launch];
+
+	NSAssert([readShipIt isRunning], @"Could not start task %@", readShipIt);
+
+	atexit_b(^{
+		[readShipIt terminate];
+	});
+}
+
+- (void)setUp {
+	[super setUp];
+
+	signal(SIGILL, &SQRLSignalHandler);
+	NSSetUncaughtExceptionHandler(&SQRLUncaughtExceptionHandler);
+
+	Expecta.asynchronousTestTimeout = 3;
+}
+
+- (void)SPT_setUp {
+	_exampleCleanupBlocks = [[NSMutableArray alloc] init];
+}
+
+- (void)SPT_tearDown {
+	NSArray *cleanupBlocks = [self.exampleCleanupBlocks copy];
+	_exampleCleanupBlocks = nil;
+
+	// Enumerate backwards, so later resources are cleaned up first.
+	for (dispatch_block_t block in cleanupBlocks.reverseObjectEnumerator) {
+		block();
+	}
+}
+
+- (void)tearDown {
+	[super tearDown];
+
+	SQRLKillAllTestApplications();
+}
+
+- (void)addCleanupBlock:(dispatch_block_t)block {
+	[self.exampleCleanupBlocks addObject:[block copy]];
+}
+
+#pragma mark Logging
+
++ (NSTask *)tailTaskWithPaths:(RACSignal *)paths {
 	NSPipe *outputPipe = [NSPipe pipe];
 	NSFileHandle *outputHandle = outputPipe.fileHandleForReading;
 
@@ -61,112 +153,24 @@ static NSTask *SQRLTailTaskWithPaths(RACSequence *paths) {
 	return task;
 }
 
-static NSBundle *SQRLTestBundle(void) {
-	return [NSBundle bundleWithIdentifier:@"com.github.SquirrelTests"];
-}
-
-static NSMutableArray *cleanupBlocks = nil;
-
-// The URL to the temporary directory which contains `temporaryDirectoryURL` and
-// all copied test data.
-static NSURL *baseTemporaryDirectoryURL = nil;
-
-QuickConfigurationBegin(Fixtures)
-
-+ (void)configure:(Configuration *)configuration {
-	NSURL *appSupportURL = [NSFileManager.defaultManager URLForDirectory:NSApplicationSupportDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:YES error:NULL];
-	NSAssert(appSupportURL != nil, @"Could not find Application Support folder");
-
-	NSArray *folders = @[
-		@"com.github.Squirrel.TestApplication.ShipIt",
-		@"com.github.Squirrel.SquirrelTests.ShipIt",
-	];
-
-	RACSequence *URLs = [folders.rac_sequence flattenMap:^(NSString *folder) {
-		NSURL *baseURL = [appSupportURL URLByAppendingPathComponent:folder];
-		return @[
-			[baseURL URLByAppendingPathComponent:@"ShipIt_stdout.log"],
-			[baseURL URLByAppendingPathComponent:@"ShipIt_stderr.log"]
-		].rac_sequence;
-	}];
-
-	RACSequence *paths = [URLs map:^(NSURL *URL) {
-		return URL.path;
-	}];
-
-	NSTask *readShipIt = SQRLTailTaskWithPaths(paths);
-
-	[configuration beforeSuite:^{
-		signal(SIGILL, &SQRLSignalHandler);
-		NSSetUncaughtExceptionHandler(&SQRLUncaughtExceptionHandler);
-
-		cleanupBlocks = [NSMutableArray array];
-
-		for (NSURL *URL in URLs) {
-			[NSFileManager.defaultManager createDirectoryAtURL:URL.URLByDeletingLastPathComponent withIntermediateDirectories:YES attributes:nil error:NULL];
-			if (![[NSData data] writeToURL:URL atomically:YES]) {
-				NSLog(@"Could not touch log file at %@", URL);
-			}
-		}
-
-		[readShipIt launch];
-
-		NSAssert([readShipIt isRunning], @"Could not start task %@", readShipIt);
-	}];
-
-	[configuration afterSuite:^{
-		[readShipIt terminate];
-	}];
-
-	// We want to run any enqueued cleanup blocks after _and before_ each spec,
-	// in case beforeSuites (for example) use the fixtures.
-	void (^runCleanupBlocks)(void) = ^{
-		// Enumerate backwards, so later resources are cleaned up first.
-		for (dispatch_block_t block in cleanupBlocks.reverseObjectEnumerator) {
-			block();
-		}
-
-		[cleanupBlocks removeAllObjects];
-	};
-
-	[configuration beforeEach:^{
-		runCleanupBlocks();
-	}];
-
-	[configuration afterEach:^{
-		runCleanupBlocks();
-		SQRLKillAllTestApplications();
-	}];
-}
-
-QuickConfigurationEnd
-
-@implementation QuickSpec (SQRLFixtures)
-
-#pragma mark Lifecycle
-
-- (void)addCleanupBlock:(dispatch_block_t)block {
-	[cleanupBlocks addObject:[block copy]];
-}
-
 #pragma mark Temporary Directory
 
 - (NSURL *)baseTemporaryDirectoryURL {
-	if (baseTemporaryDirectoryURL == nil) {
+	if (_baseTemporaryDirectoryURL == nil) {
 		NSURL *globalTemporaryDirectory = [NSURL fileURLWithPath:NSTemporaryDirectory() isDirectory:YES];
-		baseTemporaryDirectoryURL = [[globalTemporaryDirectory URLByAppendingPathComponent:@"com.github.SquirrelTests"] URLByAppendingPathComponent:[NSProcessInfo.processInfo globallyUniqueString]];
-
+		_baseTemporaryDirectoryURL = [[globalTemporaryDirectory URLByAppendingPathComponent:@"com.github.SquirrelTests"] URLByAppendingPathComponent:[NSProcessInfo.processInfo globallyUniqueString]];
+		
 		NSError *error = nil;
-		BOOL success = [NSFileManager.defaultManager createDirectoryAtURL:baseTemporaryDirectoryURL withIntermediateDirectories:YES attributes:nil error:&error];
-		XCTAssertTrue(success, @"Couldn't create temporary directory at %@: %@", baseTemporaryDirectoryURL, error);
+		BOOL success = [NSFileManager.defaultManager createDirectoryAtURL:_baseTemporaryDirectoryURL withIntermediateDirectories:YES attributes:nil error:&error];
+		STAssertTrue(success, @"Couldn't create temporary directory at %@: %@", _baseTemporaryDirectoryURL, error);
 
 		[self addCleanupBlock:^{
-			[NSFileManager.defaultManager removeItemAtURL:baseTemporaryDirectoryURL error:NULL];
-			baseTemporaryDirectoryURL = nil;
+			[NSFileManager.defaultManager removeItemAtURL:_baseTemporaryDirectoryURL error:NULL];
+			_baseTemporaryDirectoryURL = nil;
 		}];
 	}
 
-	return baseTemporaryDirectoryURL;
+	return _baseTemporaryDirectoryURL;
 }
 
 - (NSURL *)temporaryDirectoryURL {
@@ -174,7 +178,7 @@ QuickConfigurationEnd
 
 	NSError *error = nil;
 	BOOL success = [NSFileManager.defaultManager createDirectoryAtURL:temporaryDirectoryURL withIntermediateDirectories:YES attributes:nil error:&error];
-	XCTAssertTrue(success, @"Couldn't create temporary directory at %@: %@", temporaryDirectoryURL, error);
+	STAssertTrue(success, @"Couldn't create temporary directory at %@: %@", temporaryDirectoryURL, error);
 
 	return temporaryDirectoryURL;
 }
@@ -184,20 +188,20 @@ QuickConfigurationEnd
 - (NSURL *)testApplicationURL {
 	NSURL *fixtureURL = [self.temporaryDirectoryURL URLByAppendingPathComponent:@"TestApplication.app" isDirectory:YES];
 	if (![NSFileManager.defaultManager fileExistsAtPath:fixtureURL.path]) {
-		NSURL *bundleURL = [SQRLTestBundle() URLForResource:@"TestApplication" withExtension:@"app"];
-		XCTAssertNotNil(bundleURL, @"Couldn't find TestApplication.app in test bundle");
+		NSURL *bundleURL = [[NSBundle bundleForClass:self.class] URLForResource:@"TestApplication" withExtension:@"app"];
+		STAssertNotNil(bundleURL, @"Couldn't find TestApplication.app in test bundle");
 
 		NSError *error = nil;
 		BOOL success = [NSFileManager.defaultManager copyItemAtURL:bundleURL toURL:fixtureURL error:&error];
-		XCTAssertTrue(success, @"Couldn't copy %@ to %@: %@", bundleURL, fixtureURL, error);
+		STAssertTrue(success, @"Couldn't copy %@ to %@: %@", bundleURL, fixtureURL, error);
 
 		NSURL *testAppLog = [fixtureURL.URLByDeletingLastPathComponent URLByAppendingPathComponent:@"TestApplication.log"];
 		[[NSData data] writeToURL:testAppLog atomically:YES];
 
-		NSTask *readTestApp = SQRLTailTaskWithPaths([RACSequence return:testAppLog.path]);
+		NSTask *readTestApp = [self.class tailTaskWithPaths:[RACSignal return:testAppLog.path]];
 		[readTestApp launch];
 
-		XCTAssertTrue([readTestApp isRunning], @"Could not start task %@ to read %@", readTestApp, testAppLog);
+		STAssertTrue([readTestApp isRunning], @"Could not start task %@ to read %@", readTestApp, testAppLog);
 
 		[self addCleanupBlock:^{
 			[readTestApp terminate];
@@ -210,8 +214,8 @@ QuickConfigurationEnd
 - (NSBundle *)testApplicationBundle {
 	NSURL *fixtureURL = self.testApplicationURL;
 	NSBundle *bundle = [NSBundle bundleWithURL:fixtureURL];
-	XCTAssertNotNil(bundle, @"Couldn't open bundle at %@", fixtureURL);
-
+	STAssertNotNil(bundle, @"Couldn't open bundle at %@", fixtureURL);
+	
 	return bundle;
 }
 
@@ -230,7 +234,7 @@ QuickConfigurationEnd
 
 	NSError *error = nil;
 	NSRunningApplication *app = [NSWorkspace.sharedWorkspace launchApplicationAtURL:self.testApplicationURL options:NSWorkspaceLaunchWithoutAddingToRecents | NSWorkspaceLaunchWithoutActivation | NSWorkspaceLaunchNewInstance | NSWorkspaceLaunchAndHide configuration:configuration error:&error];
-	XCTAssertNotNil(app, @"Could not launch app at %@: %@", self.testApplicationURL, error);
+	STAssertNotNil(app, @"Could not launch app at %@: %@", self.testApplicationURL, error);
 
 	[self addCleanupBlock:^{
 		if (!app.terminated) {
@@ -250,12 +254,12 @@ QuickConfigurationEnd
 }
 
 - (NSURL *)createTestApplicationUpdate {
-	NSURL *originalURL = [SQRLTestBundle() URLForResource:@"TestApplication 2.1" withExtension:@"app"];
-	XCTAssertNotNil(originalURL, @"Couldn't find TestApplication update in test bundle");
+	NSURL *originalURL = [[NSBundle bundleForClass:self.class] URLForResource:@"TestApplication 2.1" withExtension:@"app"];
+	STAssertNotNil(originalURL, @"Couldn't find TestApplication update in test bundle");
 
 	NSError *error = nil;
 	NSURL *updateParentURL = [NSFileManager.defaultManager URLForDirectory:NSItemReplacementDirectory inDomain:NSUserDomainMask appropriateForURL:self.baseTemporaryDirectoryURL create:YES error:&error];
-	XCTAssertNotNil(updateParentURL, @"Could not create temporary directory for updating: %@", error);
+	STAssertNotNil(updateParentURL, @"Could not create temporary directory for updating: %@", error);
 
 	[self addCleanupBlock:^{
 		[NSFileManager.defaultManager removeItemAtURL:updateParentURL error:NULL];
@@ -263,18 +267,18 @@ QuickConfigurationEnd
 
 	NSURL *updateURL = [updateParentURL URLByAppendingPathComponent:originalURL.lastPathComponent isDirectory:YES];
 	BOOL success = [NSFileManager.defaultManager copyItemAtURL:originalURL toURL:updateURL error:&error];
-	XCTAssertTrue(success, @"Couldn't copy %@ to %@: %@", originalURL, updateURL, error);
+	STAssertTrue(success, @"Couldn't copy %@ to %@: %@", originalURL, updateURL, error);
 
 	return updateURL;
 }
 
 - (id)performWithTestApplicationRequirement:(id (^)(SecRequirementRef requirement))block {
-	NSURL *bundleURL = [SQRLTestBundle() URLForResource:@"TestApplication" withExtension:@"app"];
-	XCTAssertNotNil(bundleURL, @"Couldn't find TestApplication.app in test bundle");
+	NSURL *bundleURL = [[NSBundle bundleForClass:self.class] URLForResource:@"TestApplication" withExtension:@"app"];
+	STAssertNotNil(bundleURL, @"Couldn't find TestApplication.app in test bundle");
 
 	SecStaticCodeRef staticCode = NULL;
 	OSStatus status = SecStaticCodeCreateWithPath((__bridge CFURLRef)bundleURL, kSecCSDefaultFlags, &staticCode);
-	XCTAssertTrue(status == noErr, @"Error creating static code object for %@", bundleURL);
+	STAssertTrue(status == noErr, @"Error creating static code object for %@", bundleURL);
 
 	@onExit {
 		if (staticCode != NULL) CFRelease(staticCode);
@@ -282,7 +286,7 @@ QuickConfigurationEnd
 
 	SecRequirementRef requirement = NULL;
 	status = SecCodeCopyDesignatedRequirement(staticCode, kSecCSDefaultFlags, &requirement);
-	XCTAssertTrue(status == noErr, @"Error getting designated requirement of %@", staticCode);
+	STAssertTrue(status == noErr, @"Error getting designated requirement of %@", staticCode);
 
 	@onExit {
 		if (requirement != NULL) CFRelease(requirement);
@@ -292,57 +296,48 @@ QuickConfigurationEnd
 }
 
 - (SQRLCodeSignature *)testApplicationSignature {
-	NSURL *bundleURL = [SQRLTestBundle() URLForResource:@"TestApplication" withExtension:@"app"];
-	XCTAssertNotNil(bundleURL, @"Couldn't find TestApplication.app in test bundle");
+	return [self performWithTestApplicationRequirement:^(SecRequirementRef requirement) {
+		return [[SQRLCodeSignature alloc] initWithRequirement:requirement];
+	}];
+}
 
-	NSError *error = nil;
-	SQRLCodeSignature *signature = [SQRLCodeSignature signatureWithBundle:bundleURL error:&error];
-	XCTAssertNotNil(signature, @"Error getting signature for bundle at %@: %@", bundleURL, error);
+- (NSData *)testApplicationCodeSigningRequirementData {
+	return [self performWithTestApplicationRequirement:^(SecRequirementRef requirement) {
+		CFDataRef data = NULL;
+		OSStatus status = SecRequirementCopyData(requirement, kSecCSDefaultFlags, &data);
+		STAssertTrue(status == noErr, @"Error copying data for requirement %@", requirement);
 
-	return signature;
+		return CFBridgingRelease(data);
+	}];
 }
 
 - (SQRLDirectoryManager *)shipItDirectoryManager {
 	NSString *identifier = SQRLShipItLauncher.shipItJobLabel;
 	SQRLDirectoryManager *manager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:identifier];
-	XCTAssertNotNil(manager, @"Could not create directory manager for %@", identifier);
+	STAssertNotNil(manager, @"Could not create directory manager for %@", identifier);
 
 	return manager;
 }
 
-- (void)installWithRequest:(SQRLShipItRequest *)request remote:(BOOL)remote {
-	if (remote) {
-		expect(@([[request writeUsingURL:self.shipItDirectoryManager.shipItStateURL] waitUntilCompleted:NULL])).to(beTruthy());
+- (void)launchShipIt {
+	NSError *error = nil;
+	STAssertTrue([[SQRLShipItLauncher launchPrivileged:NO] waitUntilCompleted:&error], @"Could not launch ShipIt: %@", error);
 
-		__block NSError *error = nil;
-		expect(@([[SQRLShipItLauncher launchPrivileged:NO] waitUntilCompleted:&error])).to(beTruthy());
-		expect(error).to(beNil());
+	[self addCleanupBlock:^{
+		// Remove ShipIt's launchd job so it doesn't relaunch itself.
+		SMJobRemove(kSMDomainUserLaunchd, (__bridge CFStringRef)SQRLShipItLauncher.shipItJobLabel, NULL, true, NULL);
 
-		[self addCleanupBlock:^{
-			// Remove ShipIt's launchd job so it doesn't relaunch itself.
-			SMJobRemove(kSMDomainUserLaunchd, (__bridge CFStringRef)SQRLShipItLauncher.shipItJobLabel, NULL, true, NULL);
-
-			NSError *lookupError;
-			NSURL *stateURL = [[self.shipItDirectoryManager shipItStateURL] firstOrDefault:nil success:NULL error:&lookupError];
-			expect(stateURL).notTo(beNil());
-			expect(lookupError).to(beNil());
-
-			[NSFileManager.defaultManager removeItemAtURL:stateURL error:NULL];
-		}];
-	} else {
-		SQRLInstaller *installer = [[SQRLInstaller alloc] initWithApplicationIdentifier:self.shipItDirectoryManager.applicationIdentifier];
-		expect(installer).notTo(beNil());
-
-		NSError *installedError = nil;
-		BOOL installed = [[installer.installUpdateCommand execute:request] asynchronouslyWaitUntilCompleted:&installedError];
-		expect(@(installed)).to(beTruthy());
-		expect(installedError).to(beNil());
-	}
+		NSError *lookupError = nil;
+		NSURL *stateURL = [[self.shipItDirectoryManager shipItStateURL] firstOrDefault:nil success:NULL error:&lookupError];
+		STAssertNotNil(stateURL, @"Could not find state URL from %@: %@", self.shipItDirectoryManager, lookupError);
+		
+		[NSFileManager.defaultManager removeItemAtURL:stateURL error:NULL];
+	}];
 }
 
 - (NSURL *)createAndMountDiskImageNamed:(NSString *)name fromDirectory:(NSURL *)directoryURL {
 	NSURL *destinationURL = [self.baseTemporaryDirectoryURL URLByAppendingPathComponent:name];
-	XCTAssertNotNil(destinationURL, @"Could not create disk image URL for %@", directoryURL);
+	STAssertNotNil(destinationURL, @"Could not create disk image URL for %@", directoryURL);
 
 	NSString *createInvocation;
 	if (directoryURL == nil) {
@@ -351,15 +346,15 @@ QuickConfigurationEnd
 		createInvocation = [NSString stringWithFormat:@"hdiutil create '%@' -fs 'HFS+' -volname '%@' -format UDSP -size 10m -srcfolder '%@' -quiet", destinationURL.path, name, directoryURL.path];
 	}
 
-	expect(@(system(createInvocation.UTF8String))).to(equal(@0));
+	expect(system(createInvocation.UTF8String)).to.equal(0);
 
 	NSString *mountInvocation = [NSString stringWithFormat:@"hdiutil attach '%@.sparseimage' -noverify -noautofsck -readwrite -quiet", destinationURL.path];
-	expect(@(system(mountInvocation.UTF8String))).to(equal(@0));
+	expect(system(mountInvocation.UTF8String)).to.equal(0);
 
 	NSString *path = [NSString stringWithFormat:@"/Volumes/%@", name];
 	[self addCleanupBlock:^{
 		NSString *detachInvocation = [NSString stringWithFormat:@"hdiutil detach '%@' -force -quiet", path];
-		expect(@(system(detachInvocation.UTF8String))).to(equal(@0));
+		expect(system(detachInvocation.UTF8String)).to.equal(0);
 	}];
 
 	return [NSURL fileURLWithPath:path isDirectory:YES];

SquirrelTests/SQRLURLConnectionSpec.m

@@ -0,0 +1,311 @@
+//
+//  SQRLURLConnectionSpec.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 27/09/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "SQRLURLConnection.h"
+#import "SQRLDownloadManager.h"
+#import "SQRLResumableDownload.h"
+#import <ReactiveCocoa/EXTScope.h>
+#import "NSError+SQRLVerbosityExtensions.h"
+#import "SQRLHTTPServer.h"
+
+SpecBegin(SQRLURLConnection);
+
+__block SQRLDownloadManager *downloadManager;
+
+beforeAll(^{
+	downloadManager = SQRLDownloadManager.defaultDownloadManager;
+
+	NSError *removeError = nil;
+	BOOL remove = [[downloadManager
+		removeAllResumableDownloads]
+		waitUntilCompleted:&removeError];
+	expect(remove).to.beTruthy();
+	expect(removeError).to.beNil();
+});
+
+beforeEach(^{
+	Expecta.asynchronousTestTimeout = 60.;
+});
+
+afterAll(^{
+	Expecta.asynchronousTestTimeout = 1.;
+});
+
+describe(@"file scheme URLs", ^{
+	NSURL *fileLocation = [self.temporaryDirectoryURL URLByAppendingPathComponent:@"test"];
+	NSData *testContents = [@"test" dataUsingEncoding:NSUTF8StringEncoding];
+
+	NSError *error;
+	BOOL write = [testContents writeToURL:fileLocation options:0 error:&error];
+	expect(write).to.beTruthy();
+	expect(error).to.beNil();
+
+	NSURLRequest *request = [NSURLRequest requestWithURL:fileLocation];
+
+	__block SQRLURLConnection *connection;
+
+	beforeEach(^{
+		connection = [[SQRLURLConnection alloc] initWithRequest:request];
+	});
+
+	void (^testBodyEqualTestContents)(NSData *) = ^ (NSData *body) {
+		expect(body.length).to.equal(testContents.length);
+		expect(body).to.equal(testContents);
+	};
+
+	it(@"should retrieve file:// scheme URLs", ^{
+		NSError *error;
+		RACTuple *result = [[connection retrieve] firstOrDefault:nil success:NULL error:&error];
+		expect(result).notTo.beNil();
+		expect(error).to.beNil();
+
+		testBodyEqualTestContents(result[1]);
+	});
+
+	it(@"should download file:// scheme URLs", ^{
+		NSError *error;
+		RACTuple *result = [[connection download:downloadManager] firstOrDefault:nil success:NULL error:&error];
+		expect(result).notTo.beNil();
+		expect(error).to.beNil();
+
+		NSURL *location = result[1];
+
+		NSData *body = [NSData dataWithContentsOfURL:location options:0 error:&error];
+		expect(error).to.beNil();
+		testBodyEqualTestContents(body);
+	});
+});
+
+static NSData * (^stringTimes)(NSString *, NSUInteger) = ^ (NSString *string, NSUInteger times) {
+	NSData *stringData = [string dataUsingEncoding:NSUTF8StringEncoding];
+	NSMutableData *data = [NSMutableData dataWithCapacity:(stringData.length + 2) * times];
+	for (NSUInteger idx = 0; idx < times; idx++) {
+		[data appendData:stringData];
+		[data appendData:[NSData dataWithBytes:"\r\n" length:2]];
+	}
+	return data;
+};
+
+static SQRLHTTPServer * (^newHttpServer)(SQRLTestCase *) = ^ (SQRLTestCase *self) {
+	SQRLHTTPServer *server = [[SQRLHTTPServer alloc] init];
+
+	[self addCleanupBlock:^{
+		[server invalidate];
+	}];
+
+	return server;
+};
+
+it(@"should resume a download", ^{
+	// Start server
+
+	SQRLHTTPServer *server = newHttpServer(self);
+
+	NSError *error = nil;
+	NSURL *baseURL = [server start:&error];
+	expect(baseURL).notTo.beNil();
+	expect(error).to.beNil();
+
+	error = nil;
+
+
+	// Prepare half response
+
+	NSData *firstHalf = stringTimes(@"the quick brown fox", 100);
+	NSData *secondHalf = stringTimes(@"jumped over the lazy doge", 100);
+
+	NSString *ETag = NSProcessInfo.processInfo.globallyUniqueString;
+
+	CFHTTPMessageRef serverResponse = (__bridge CFHTTPMessageRef)CFBridgingRelease(CFHTTPMessageCreateResponse(kCFAllocatorDefault, 200, NULL, kCFHTTPVersion1_1));
+	NSDictionary *responseHeaders = @{
+		@"Content-Length": [@(firstHalf.length + secondHalf.length) stringValue],
+		@"ETag": ETag,
+	};
+	[responseHeaders enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *obj, BOOL *stop) {
+		CFHTTPMessageSetHeaderFieldValue(serverResponse, (__bridge CFStringRef)key, (__bridge CFStringRef)obj);
+	}];
+	CFHTTPMessageSetBody(serverResponse, (__bridge CFDataRef)firstHalf);
+
+	server.responseBlock = ^ (CFHTTPMessageRef request) {
+		NSString *ifRange = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("If-Range")));
+		expect(ifRange).to.beNil();
+
+		NSString *range = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("Range")));
+		expect(range).to.beNil();
+
+		return serverResponse;
+	};
+
+
+	// Issue first request
+
+	NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:baseURL];
+	request.timeoutInterval = 1.;
+	SQRLURLConnection *connection = [[SQRLURLConnection alloc] initWithRequest:request];
+	RACTuple *result = [[connection download:downloadManager] firstOrDefault:nil success:NULL error:&error];
+	expect(result).to.beNil();
+	expect(error).notTo.beNil();
+
+	error = nil;
+
+	SQRLResumableDownload *download = [[downloadManager downloadForRequest:request] firstOrDefault:nil success:NULL error:&error];
+	expect(download).notTo.beNil();
+	expect(error).to.beNil();
+
+	NSData *downloadedData = [NSData dataWithContentsOfURL:download.fileURL options:0 error:&error];
+	expect(downloadedData.length).to.equal(firstHalf.length);
+	expect(downloadedData).to.equal(firstHalf);
+	expect(error).to.beNil();
+
+
+	// Prepare remainder response
+
+	serverResponse = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 206, NULL, kCFHTTPVersion1_1);
+	responseHeaders = @{
+		@"Content-Length": [@(secondHalf.length) stringValue],
+		@"Range": [NSString stringWithFormat:@"%lu-%lu", firstHalf.length, secondHalf.length - 1],
+		@"ETag": ETag,
+	};
+	[responseHeaders enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *obj, BOOL *stop) {
+		CFHTTPMessageSetHeaderFieldValue(serverResponse, (__bridge CFStringRef)key, (__bridge CFStringRef)obj);
+	}];
+	CFHTTPMessageSetBody(serverResponse, (__bridge CFDataRef)secondHalf);
+
+	server.responseBlock = ^ (CFHTTPMessageRef request) {
+		NSString *ifRange = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("If-Range")));
+		expect(ifRange).to.equal(ETag);
+
+		NSString *range = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("Range")));
+		expect(range).to.equal(([NSString stringWithFormat:@"%lu-", firstHalf.length]));
+
+		return serverResponse;
+	};
+
+
+	// Issue second request
+
+	connection = [[SQRLURLConnection alloc] initWithRequest:request];
+	result = [[connection download:downloadManager] firstOrDefault:nil success:NULL error:&error];
+	expect(result).notTo.beNil();
+	expect(error).to.beNil();
+
+	NSURL *location = result[1];
+
+	NSMutableData *fullBody = [firstHalf mutableCopy];
+	[fullBody appendData:secondHalf];
+
+	downloadedData = [NSData dataWithContentsOfURL:location options:0 error:&error];
+	expect(downloadedData.length).to.equal(fullBody.length);
+	expect(downloadedData).to.equal(fullBody);
+	expect(error).to.beNil();
+});
+
+it(@"should not resume downloads for a response with a different ETag", ^{
+	// Start server
+
+	SQRLHTTPServer *server = newHttpServer(self);
+
+	NSError *error = nil;
+	NSURL *baseURL = [server start:&error];
+	expect(baseURL).notTo.beNil();
+	expect(error).to.beNil();
+
+	error = nil;
+
+
+	// Prepare first response
+
+	NSData *firstBody = stringTimes(@"the quick brown fox", 100);
+	NSString *firstETag = NSProcessInfo.processInfo.globallyUniqueString;
+
+	CFHTTPMessageRef serverResponse = (__bridge CFHTTPMessageRef)CFBridgingRelease(CFHTTPMessageCreateResponse(kCFAllocatorDefault, 200, NULL, kCFHTTPVersion1_1));
+	NSDictionary *responseHeaders = @{
+		// Claim the response to be longer so that the connection will timeout
+		// waiting for the extra bytes
+		@"Content-Length": [@(firstBody.length + 100) stringValue],
+		@"ETag": firstETag,
+	};
+	[responseHeaders enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *obj, BOOL *stop) {
+		CFHTTPMessageSetHeaderFieldValue(serverResponse, (__bridge CFStringRef)key, (__bridge CFStringRef)obj);
+	}];
+	CFHTTPMessageSetBody(serverResponse, (__bridge CFDataRef)firstBody);
+
+	server.responseBlock = ^ (CFHTTPMessageRef request) {
+		NSString *ifRange = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("If-Range")));
+		expect(ifRange).to.beNil();
+
+		NSString *range = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("Range")));
+		expect(range).to.beNil();
+
+		return serverResponse;
+	};
+
+
+	// Issue first request
+
+	NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:baseURL];
+	request.timeoutInterval = 1.;
+	SQRLURLConnection *connection = [[SQRLURLConnection alloc] initWithRequest:request];
+	RACTuple *result = [[connection download:downloadManager] firstOrDefault:nil success:NULL error:&error];
+	expect(result).to.beNil();
+	expect(error).notTo.beNil();
+
+	error = nil;
+
+	SQRLResumableDownload *download = [[downloadManager downloadForRequest:request] firstOrDefault:nil success:NULL error:&error];
+	expect(download).notTo.beNil();
+	expect(error).to.beNil();
+
+	NSData *downloadedData = [NSData dataWithContentsOfURL:download.fileURL options:0 error:&error];
+	expect(downloadedData.length).to.equal(firstBody.length);
+	expect(downloadedData).to.equal(firstBody);
+	expect(error).to.beNil();
+
+
+	// Prepare second response
+
+	NSData *secondBody = stringTimes(@"jumps over the lazy doge", 100);
+	NSString *secondETag = NSProcessInfo.processInfo.globallyUniqueString;
+
+	serverResponse = (__bridge CFHTTPMessageRef)CFBridgingRelease(CFHTTPMessageCreateResponse(kCFAllocatorDefault, 200, NULL, kCFHTTPVersion1_1));
+	responseHeaders = @{
+		@"Content-Length": [@(secondBody.length) stringValue],
+		@"ETag": secondETag,
+	};
+	[responseHeaders enumerateKeysAndObjectsUsingBlock:^(NSString *key, NSString *obj, BOOL *stop) {
+		CFHTTPMessageSetHeaderFieldValue(serverResponse, (__bridge CFStringRef)key, (__bridge CFStringRef)obj);
+	}];
+	CFHTTPMessageSetBody(serverResponse, (__bridge CFDataRef)secondBody);
+
+	server.responseBlock = ^ (CFHTTPMessageRef request) {
+		NSString *ifRange = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("If-Range")));
+		expect(ifRange).to.equal(firstETag);
+
+		NSString *range = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(request, CFSTR("Range")));
+		expect(range).to.equal(([NSString stringWithFormat:@"%lu-", firstBody.length]));
+
+		return serverResponse;
+	};
+
+
+	// Issue second request
+
+	connection = [[SQRLURLConnection alloc] initWithRequest:request];
+	result = [[connection download:downloadManager] firstOrDefault:nil success:NULL error:&error];
+	expect(result).notTo.beNil();
+	expect(error).to.beNil();
+
+	NSURL *location = result[1];
+
+	downloadedData = [NSData dataWithContentsOfURL:location options:0 error:&error];
+	expect(downloadedData.length).to.equal(secondBody.length);
+	expect(downloadedData).to.equal(secondBody);
+	expect(error).to.beNil();
+});
+
+SpecEnd

SquirrelTests/SQRLUpdateSpec.m

@@ -6,27 +6,22 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
-QuickSpecBegin(SQRLUpdateSpec)
+SpecBegin(SQRLUpdate)
 
 it(@"should return nil when initialised without a url", ^{
 	NSError *error = nil;
 	SQRLUpdate *update = [[SQRLUpdate alloc] initWithDictionary:@{} error:&error];
-	expect(update).to(beNil());
-	expect(error.domain).to(equal(NSCocoaErrorDomain));
-	expect(@(error.code)).to(equal(@(NSKeyValueValidationError)));
+	expect(update).to.beNil();
+	expect(error.domain).to.equal(NSCocoaErrorDomain);
+	expect(error.code).to.equal(NSKeyValueValidationError);
 });
 
 it(@"should return nil when initialised with a url not in URL syntax", ^{
 	NSError *error = nil;
 	SQRLUpdate *update = [[SQRLUpdate alloc] initWithDictionary:@{ @"updateURL": [NSURL URLWithString:@"test"] } error:&error];
-	expect(update).to(beNil());
-	expect(error.domain).to(equal(NSCocoaErrorDomain));
-	expect(@(error.code)).to(equal(@(NSKeyValueValidationError)));
+	expect(update).to.beNil();
+	expect(error.domain).to.equal(NSCocoaErrorDomain);
+	expect(error.code).to.equal(NSKeyValueValidationError);
 });
 
 it(@"should validate release name and notes", ^{
@@ -37,20 +32,24 @@ it(@"should validate release name and notes", ^{
 		@"releaseNotes": [[NSObject alloc] init]
 	} error:NULL];
 
-	expect(update).notTo(beNil());
-	expect(update.updateURL).to(equal(updateURL));
-	expect(update.releaseName).to(beNil());
-	expect(update.releaseNotes).to(beNil());
+	expect(update).notTo.beNil();
+	expect(update.updateURL).to.equal(updateURL);
+	expect(update.releaseName).to.beNil();
+	expect(update.releaseNotes).to.beNil();
 });
 
 it(@"should parse Central style dates", ^{
-	SQRLUpdate *update = [MTLJSONAdapter modelOfClass:SQRLUpdate.class fromJSONDictionary:@{ @"url": @"http://example.com/update", @"pub_date": @"Tue Sep 17 10:24:27 -0700 2013" } error:NULL];
-	expect(update.releaseDate).notTo(beNil());
+	NSError *error = nil;
+	SQRLUpdate *update = [MTLJSONAdapter modelOfClass:SQRLUpdate.class fromJSONDictionary:@{ @"url": @"http://example.com/update", @"pub_date": @"Tue Sep 17 10:24:27 -0700 2013" } error:&error];
+	expect(update.releaseDate).notTo.beNil();
+	expect(error).to.beNil();
 });
 
 it(@"should parse ISO 8601 dates", ^{
-	SQRLUpdate *update = [MTLJSONAdapter modelOfClass:SQRLUpdate.class fromJSONDictionary:@{ @"url": @"http://example.com/update", @"pub_date": @"2013-09-18T13:17:07+01:00" } error:NULL];
-	expect(update.releaseDate).notTo(beNil());
+	NSError *error = nil;
+	SQRLUpdate *update = [MTLJSONAdapter modelOfClass:SQRLUpdate.class fromJSONDictionary:@{ @"url": @"http://example.com/update", @"pub_date": @"2013-09-18T13:17:07+01:00" } error:&error];
+	expect(update.releaseDate).notTo.beNil();
+	expect(error).to.beNil();
 });
 
-QuickSpecEnd
+SpecEnd

SquirrelTests/SQRLUpdaterSpec.m

@@ -6,44 +6,38 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
-#import "SQRLDirectoryManager.h"
-#import "SQRLZipArchiver.h"
-
-#import "OHHTTPStubs/OHHTTPStubs.h"
-#import "QuickSpec+SQRLFixtures.h"
 #import "SQRLTestUpdate.h"
-#import "TestAppConstants.h"
+#import "SQRLZipArchiver.h"
+#import "OHHTTPStubs/OHHTTPStubs.h"
+#import "SQRLDirectoryManager.h"
+#import "SQRLURLConnection.h"
+#import "SQRLDownloadManager.h"
 
-QuickSpecBegin(SQRLUpdaterSpec)
+SpecBegin(SQRLUpdater)
 
 __block NSURL *JSONURL;
 
 void (^writeUpdate)(SQRLUpdate *) = ^(SQRLUpdate *update) {
 	NSDictionary *updateInfo = [MTLJSONAdapter JSONDictionaryFromModel:update];
-	expect(updateInfo).notTo(beNil());
+	expect(updateInfo).notTo.beNil();
 
 	NSError *error = nil;
 	NSData *JSON = [NSJSONSerialization dataWithJSONObject:updateInfo options:NSJSONWritingPrettyPrinted error:&error];
-	expect(JSON).notTo(beNil());
-	expect(error).to(beNil());
+	expect(JSON).notTo.beNil();
+	expect(error).to.beNil();
 
 	BOOL success = [JSON writeToURL:JSONURL options:NSDataWritingAtomic error:&error];
-	expect(@(success)).to(beTruthy());
-	expect(error).to(beNil());
+	expect(success).to.beTruthy();
+	expect(error).to.beNil();
 };
 
 NSURL * (^zipUpdate)(NSURL *) = ^(NSURL *updateURL) {
 	NSURL *zipFolderURL = [NSFileManager.defaultManager URLForDirectory:NSItemReplacementDirectory inDomain:NSUserDomainMask appropriateForURL:self.temporaryDirectoryURL create:YES error:NULL];
-	expect(zipFolderURL).notTo(beNil());
+	expect(zipFolderURL).notTo.beNil();
 
 	NSURL *zippedUpdateURL = [[zipFolderURL URLByAppendingPathComponent:updateURL.lastPathComponent] URLByAppendingPathExtension:@"zip"];
 	BOOL success = [[SQRLZipArchiver createZipArchiveAtURL:zippedUpdateURL fromDirectoryAtURL:updateURL] asynchronouslyWaitUntilCompleted:NULL];
-	expect(@(success)).to(beTruthy());
+	expect(success).to.beTruthy();
 
 	return zippedUpdateURL;
 };
@@ -59,139 +53,96 @@ beforeEach(^{
 	JSONURL = [self.temporaryDirectoryURL URLByAppendingPathComponent:@"update.json"];
 });
 
-describe(@"updating", ^{
-	__block NSURL *updateURL;
+it(@"should use the application's bundled version of Squirrel and update in-place", ^{
+	NSURL *updateURL = [self createTestApplicationUpdate];
 
-	beforeEach(^{
-		updateURL = [self createTestApplicationUpdate];
-	});
+	NSError *error = nil;
+	SQRLTestUpdate *update = [SQRLTestUpdate modelWithDictionary:@{
+		@"updateURL": zipUpdate(updateURL),
+		@"final": @YES
+	} error:&error];
+	expect(update).notTo.beNil();
+	expect(error).to.beNil();
 
-	it(@"should use the application's bundled version of Squirrel and update in-place", ^{
-		NSError *error = nil;
-		SQRLTestUpdate *update = [SQRLTestUpdate modelWithDictionary:@{
-			@"updateURL": zipUpdate(updateURL),
-			@"final": @YES
-		} error:&error];
-		expect(update).notTo(beNil());
-		expect(error).to(beNil());
+	writeUpdate(update);
 
-		writeUpdate(update);
+	NSRunningApplication *app = launchWithEnvironment(nil);
+	expect(app.terminated).will.beTruthy();
+	expect(self.testApplicationBundleVersion).will.equal(SQRLTestApplicationUpdatedShortVersionString);
+});
 
-		NSRunningApplication *app = launchWithEnvironment(nil);
-		expect(@(app.terminated)).toEventually(beTruthy());
-		expect(self.testApplicationBundleVersion).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
-	});
+it(@"should not install a corrupt update", ^{
+	NSURL *updateURL = [self createTestApplicationUpdate];
+	NSURL *codeSignatureURL = [updateURL URLByAppendingPathComponent:@"Contents/_CodeSignature"];
+	expect([NSFileManager.defaultManager removeItemAtURL:codeSignatureURL error:NULL]).to.beTruthy();
 
-	it(@"should not install a corrupt update", ^{
-		NSURL *codeSignatureURL = [updateURL URLByAppendingPathComponent:@"Contents/_CodeSignature"];
-		expect(@([NSFileManager.defaultManager removeItemAtURL:codeSignatureURL error:NULL])).to(beTruthy());
+	SQRLTestUpdate *update = [SQRLTestUpdate modelWithDictionary:@{
+		@"updateURL": zipUpdate(updateURL),
+		@"final": @YES
+	} error:NULL];
 
-		SQRLTestUpdate *update = [SQRLTestUpdate modelWithDictionary:@{
-			@"updateURL": zipUpdate(updateURL),
-			@"final": @YES
-		} error:NULL];
+	writeUpdate(update);
 
-		writeUpdate(update);
+	NSRunningApplication *app = launchWithEnvironment(nil);
+	expect(app.terminated).will.beTruthy();
 
-		NSRunningApplication *app = launchWithEnvironment(nil);
-		expect(@(app.terminated)).withTimeout(5).toEventually(beTruthy());
+	// Give the update some time to finish installing.
+	[NSThread sleepForTimeInterval:0.2];
+	expect(self.testApplicationBundleVersion).to.equal(SQRLTestApplicationOriginalShortVersionString);
+});
 
-		// Give the update some time to finish installing.
-		[NSThread sleepForTimeInterval:0.2];
-		expect(self.testApplicationBundleVersion).to(equal(SQRLTestApplicationOriginalShortVersionString));
-	});
+it(@"should update to the most recently enqueued job", ^{
+	SQRLTestUpdate *update = [SQRLTestUpdate modelWithDictionary:@{
+		@"updateURL": zipUpdate(self.testApplicationURL)
+	} error:NULL];
 
-	it(@"should update to the most recently enqueued job", ^{
-		SQRLTestUpdate *update = [SQRLTestUpdate modelWithDictionary:@{
-			@"updateURL": zipUpdate(self.testApplicationURL)
-		} error:NULL];
+	writeUpdate(update);
 
-		writeUpdate(update);
+	NSRunningApplication *app = launchWithEnvironment(nil);
 
-		NSRunningApplication *app = launchWithEnvironment(nil);
+	// Now that Test Application is launched, it's going to keep checking the
+	// JSON URL until it has the proper release name. So we'll wait a short bit,
+	// and then add the correct name in.
+	//
+	// This exercises ShipIt's ability to discard previous commands and
+	// install an even newer update.
+	[NSThread sleepForTimeInterval:0.3];
 
-		// Now that Test Application is launched, it's going to keep checking the
-		// JSON URL until it has the proper release name. So we'll wait a short bit,
-		// and then add the correct name in.
-		//
-		// This exercises ShipIt's ability to discard previous commands and
-		// install an even newer update.
-		[NSThread sleepForTimeInterval:0.3];
+	NSURL *updateURL = [self createTestApplicationUpdate];
+	update = [SQRLTestUpdate modelWithDictionary:@{
+		@"updateURL": zipUpdate(updateURL),
+		@"final": @YES
+	} error:NULL];
 
-		update = [SQRLTestUpdate modelWithDictionary:@{
-			@"updateURL": zipUpdate(updateURL),
-			@"final": @YES
-		} error:NULL];
+	writeUpdate(update);
 
-		writeUpdate(update);
+	expect(app.terminated).will.beTruthy();
+	expect(self.testApplicationBundleVersion).will.equal(SQRLTestApplicationUpdatedShortVersionString);
+});
 
-		expect(@(app.terminated)).withTimeout(5).toEventually(beTruthy());
-		expect(self.testApplicationBundleVersion).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
-	});
+it(@"should use the application's bundled version of Squirrel and update in-place after a significant delay", ^{
+	NSURL *updateURL = [self createTestApplicationUpdate];
+	SQRLTestUpdate *update = [SQRLTestUpdate modelWithDictionary:@{
+		@"updateURL": zipUpdate(updateURL),
+		@"final": @YES
+	} error:NULL];
 
-	it(@"should use the application's bundled version of Squirrel and update in-place after a significant delay", ^{
-		SQRLTestUpdate *update = [SQRLTestUpdate modelWithDictionary:@{
-			@"updateURL": zipUpdate(updateURL),
-			@"final": @YES
-		} error:NULL];
+	writeUpdate(update);
 
-		writeUpdate(update);
+	NSTimeInterval delay = 30;
+	NSRunningApplication *app = launchWithEnvironment(@{ @"SQRLUpdateDelay": [NSString stringWithFormat:@"%f", delay] });
 
-		NSTimeInterval delay = 15;
-		NSRunningApplication *app = launchWithEnvironment(@{ @"SQRLUpdateDelay": [NSString stringWithFormat:@"%f", delay] });
+	Expecta.asynchronousTestTimeout = delay + 3;
+	expect(app.terminated).will.beTruthy();
 
-		expect(@(app.terminated)).withTimeout(delay + 5).toEventually(beTruthy());
-		expect(self.testApplicationBundleVersion).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
-	});
-
-	describe(@"cleaning up", ^{
-		__block NSURL *appSupportURL;
-		__block RACSignal *updateDirectoryURLs;
-
-		beforeEach(^{
-			SQRLDirectoryManager *directoryManager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:@"com.github.Squirrel.TestApplication.ShipIt"];
-
-			appSupportURL = [[directoryManager applicationSupportURL] first];
-			expect(appSupportURL).notTo(beNil());
-
-			updateDirectoryURLs = [[RACSignal
-				defer:^{
-					NSArray *contents = [NSFileManager.defaultManager contentsOfDirectoryAtURL:appSupportURL includingPropertiesForKeys:nil options:0 error:NULL];
-					if (contents == nil) return [RACSignal empty];
-
-					return contents.rac_sequence.signal;
-				}]
-				filter:^(NSURL *directoryURL) {
-					return [directoryURL.lastPathComponent hasPrefix:@"update."];
-				}];
-		});
-
-		it(@"should remove downloaded archives after updating", ^{
-			NSError *error = nil;
-			SQRLTestUpdate *update = [SQRLTestUpdate modelWithDictionary:@{
-				@"updateURL": zipUpdate(updateURL),
-				@"final": @YES
-			} error:&error];
-
-			expect(update).notTo(beNil());
-			expect(error).to(beNil());
-
-			writeUpdate(update);
-
-			NSRunningApplication *app = launchWithEnvironment(nil);
-			expect(@(app.terminated)).withTimeout(5).toEventually(beTruthy());
-			expect(self.testApplicationBundleVersion).toEventually(equal(SQRLTestApplicationUpdatedShortVersionString));
-
-			expect([updateDirectoryURLs toArray]).toEventually(equal(@[]));
-		});
-	});
+	expect(self.testApplicationBundleVersion).will.equal(SQRLTestApplicationUpdatedShortVersionString);
 });
 
 describe(@"response handling", ^{
 	__block NSURLRequest *localRequest = nil;
 	__block SQRLUpdater *updater = nil;
 
-	beforeEach(^{
+	before(^{
 		localRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:@"fake://host/path"]];
 		updater = [[SQRLUpdater alloc] initWithUpdateRequest:localRequest];
 	});
@@ -207,10 +158,10 @@ describe(@"response handling", ^{
 		}];
 
 		NSError *error = nil;
-		BOOL result = [[updater.checkForUpdatesCommand execute:nil] asynchronouslyWaitUntilCompleted:&error];
-		expect(@(result)).to(beFalsy());
-		expect(error.domain).to(equal(SQRLUpdaterErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLUpdaterErrorInvalidServerResponse)));
+		BOOL result = [[updater.checkForUpdatesAction deferred] asynchronouslyWaitUntilCompleted:&error];
+		expect(result).to.beFalsy();
+		expect(error.domain).to.equal(SQRLUpdaterErrorDomain);
+		expect(error.code).to.equal(SQRLUpdaterErrorInvalidServerResponse);
 	});
 
 	it(@"should return an error for non JSON data", ^{
@@ -224,69 +175,90 @@ describe(@"response handling", ^{
 		}];
 
 		NSError *error = nil;
-		BOOL result = [[updater.checkForUpdatesCommand execute:nil] asynchronouslyWaitUntilCompleted:&error];
-		expect(@(result)).to(beFalsy());
-		expect(error.domain).to(equal(SQRLUpdaterErrorDomain));
-		expect(@(error.code)).to(equal(@(SQRLUpdaterErrorInvalidServerBody)));
+		BOOL result = [[updater.checkForUpdatesAction deferred] asynchronouslyWaitUntilCompleted:&error];
+		expect(result).to.beFalsy();
+		expect(error.domain).to.equal(SQRLUpdaterErrorDomain);
+		expect(error.code).to.equal(SQRLUpdaterErrorInvalidServerBody);
 	});
 });
 
-static RACSignal * (^stateNotificationListener)(void) = ^ {
-	return [[[NSDistributedNotificationCenter.defaultCenter
-		rac_addObserverForName:SQRLTestAppUpdaterStateTransitionNotificationName object:nil]
+it(@"should clean up resumable downloads after a successful download", ^{
+	SQRLDirectoryManager *directoryManager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:@"com.github.Squirrel.TestApplication"];
+	SQRLDownloadManager *downloadManager = [[SQRLDownloadManager alloc] initWithDirectoryManager:directoryManager];
+
+	NSError *error = nil;
+	BOOL remove = [[downloadManager removeAllResumableDownloads] asynchronouslyWaitUntilCompleted:&error];
+	expect(remove).to.beTruthy();
+	expect(error).to.beNil();
+
+	NSURL *updateApplicationBundle = [self createTestApplicationUpdate];
+
+	NSURL *firstDownload = zipUpdate(updateApplicationBundle);
+	SQRLURLConnection *connection = [[SQRLURLConnection alloc] initWithRequest:[NSURLRequest requestWithURL:firstDownload]];
+	BOOL download = [[connection download:downloadManager] asynchronouslyWaitUntilCompleted:&error];
+	expect(download).to.beTruthy();
+	expect(error).to.beNil();
+
+	NSURL *downloadDirectory = [[directoryManager downloadDirectoryURL] firstOrDefault:nil success:NULL error:&error];
+	expect(downloadDirectory).notTo.beNil();
+	expect(error).to.beNil();
+
+	NSArray *contents = [NSFileManager.defaultManager contentsOfDirectoryAtURL:downloadDirectory includingPropertiesForKeys:@[] options:0 error:&error];
+	expect(contents.count).to.equal(1);
+
+	SQRLTestUpdate *update = [[SQRLTestUpdate alloc] initWithDictionary:@{
+		@"updateURL": zipUpdate(updateApplicationBundle),
+		@"final": @YES,
+	} error:NULL];
+
+	writeUpdate(update);
+
+	NSRunningApplication *app = launchWithEnvironment(nil);
+	expect(app.terminated).will.beTruthy();
+	expect(self.testApplicationBundleVersion).will.equal(SQRLTestApplicationUpdatedShortVersionString);
+
+	contents = [NSFileManager.defaultManager contentsOfDirectoryAtURL:downloadDirectory includingPropertiesForKeys:@[] options:0 error:&error];
+	if (contents == nil) {
+		expect(error.domain).to.equal(NSCocoaErrorDomain);
+		expect(error.code).to.equal(NSFileReadNoSuchFileError);
+	} else {
+		expect(contents.count).to.equal(0);
+	}
+});
+
+it(@"should unpack update archives into a .noindex directory", ^{
+	NSURL *zippedUpdateLocation = zipUpdate([self createTestApplicationUpdate]);
+
+	SQRLTestUpdate *update = [[SQRLTestUpdate alloc] initWithDictionary:@{
+		@keypath(update.updateURL): zippedUpdateLocation,
+	} error:NULL];
+
+	writeUpdate(update);
+
+	__block SQRLDownloadedUpdate *downloadedUpdate;
+
+	[[[[[NSDistributedNotificationCenter.defaultCenter
+		rac_addObserverForName:@"com.github.Squirrel.TestApplication.updateReceived" object:nil]
 		map:^(NSNotification *notification) {
-			return notification.userInfo[SQRLTestAppUpdaterStateKey];
+			return notification.userInfo[@"update"];
 		}]
-		setNameWithFormat:@"stateNotificationListener"];
-};
-
-describe(@"state", ^{
-	it(@"should transition through idle, checking and idle, when there is no update", ^{
-		NSMutableArray *states = [NSMutableArray array];
-		[stateNotificationListener() subscribeNext:^(NSNumber *state) {
-			[states addObject:state];
+		tryMap:^(NSString *serialisedUpdate, NSError **errorRef) {
+			NSData *JSONData = [serialisedUpdate dataUsingEncoding:NSUTF8StringEncoding];
+			return [NSJSONSerialization JSONObjectWithData:JSONData options:0 error:errorRef];
+		}]
+		tryMap:^(NSDictionary *JSONDictionary, NSError **errorRef) {
+			return [MTLJSONAdapter modelOfClass:SQRLDownloadedUpdate.class fromJSONDictionary:JSONDictionary error:errorRef];
+		}]
+		subscribeNext:^(SQRLDownloadedUpdate *update) {
+			downloadedUpdate = update;
 		}];
 
-		NSRunningApplication *testApplication = launchWithEnvironment(nil);
+	launchWithEnvironment(nil);
 
-		NSArray *expectedStates = @[
-			@(SQRLUpdaterStateIdle),
-			@(SQRLUpdaterStateCheckingForUpdate),
-			@(SQRLUpdaterStateIdle),
-		];
-		expect(states).toEventually(equal(expectedStates));
+	expect(downloadedUpdate).willNot.beNil();
 
-		expect(@(testApplication.terminated)).withTimeout(5).toEventually(beTruthy());
-	});
-
-	it(@"should transition through idle, checking, downloading and awaiting relaunch, when there is an update", ^{
-		NSMutableArray *states = [NSMutableArray array];
-		[stateNotificationListener() subscribeNext:^(NSNumber *state) {
-			[states addObject:state];
-		}];
-
-		NSError *error;
-		SQRLTestUpdate *update = [SQRLTestUpdate modelWithDictionary:@{
-			@"updateURL": zipUpdate([self createTestApplicationUpdate]),
-			@"final": @YES,
-		} error:&error];
-		expect(update).notTo(beNil());
-		expect(error).to(beNil());
-
-		writeUpdate(update);
-
-		NSRunningApplication *testApplication = launchWithEnvironment(nil);
-
-		NSArray *expectedStates = @[
-			@(SQRLUpdaterStateIdle),
-			@(SQRLUpdaterStateCheckingForUpdate),
-			@(SQRLUpdaterStateDownloadingUpdate),
-			@(SQRLUpdaterStateAwaitingRelaunch),
-		];
-		expect(states).toEventually(equal(expectedStates));
-
-		expect(@(testApplication.terminated)).withTimeout(5).toEventually(beTruthy());
-	});
+	NSURL *bundleURL = downloadedUpdate.bundle.bundleURL;
+	expect([bundleURL.path rangeOfString:@".noindex"].location).notTo.equal(NSNotFound);
 });
 
-QuickSpecEnd
+SpecEnd

SquirrelTests/SQRLZipArchiverSpec.m

@@ -6,44 +6,38 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-#import <Nimble/Nimble.h>
-#import <Quick/Quick.h>
-#import <ReactiveCocoa/ReactiveCocoa.h>
-#import <Squirrel/Squirrel.h>
-
-#import "QuickSpec+SQRLFixtures.h"
 #import "SQRLCodeSignature.h"
 #import "SQRLZipArchiver.h"
 
-QuickSpecBegin(SQRLZipArchiverSpec)
+SpecBegin(SQRLZipOperation)
 
 it(@"should extract a zip archive created by the Finder", ^{
 	NSURL *zipURL = [[NSBundle bundleForClass:self.class] URLForResource:@"TestApplication.app" withExtension:@"zip"];
 
 	NSError *error = nil;
 	BOOL success = [[SQRLZipArchiver unzipArchiveAtURL:zipURL intoDirectoryAtURL:self.temporaryDirectoryURL] asynchronouslyWaitUntilCompleted:&error];
-	expect(@(success)).to(beTruthy());
-	expect(error).to(beNil());
+	expect(success).to.beTruthy();
+	expect(error).to.beNil();
 
 	NSURL *extractedAppURL = [self.temporaryDirectoryURL URLByAppendingPathComponent:@"TestApplication 2.1.app"];
-	expect(@([NSFileManager.defaultManager fileExistsAtPath:extractedAppURL.path])).to(beTruthy());
+	expect([NSFileManager.defaultManager fileExistsAtPath:extractedAppURL.path]).to.beTruthy();
 
 	success = [[self.testApplicationSignature verifyBundleAtURL:extractedAppURL] waitUntilCompleted:&error];
-	expect(@(success)).to(beTruthy());
-	expect(error).to(beNil());
+	expect(success).to.beTruthy();
+	expect(error).to.beNil();
 });
 
 it(@"should fail to extract a nonexistent zip archive", ^{
 	NSError *error = nil;
 	BOOL success = [[SQRLZipArchiver unzipArchiveAtURL:[self.temporaryDirectoryURL URLByAppendingPathComponent:@"foo.zip"] intoDirectoryAtURL:self.temporaryDirectoryURL] asynchronouslyWaitUntilCompleted:&error];
-	expect(@(success)).to(beFalsy());
+	expect(success).to.beFalsy();
 
 	NSLog(@"%@", error);
 
-	expect(error).notTo(beNil());
-	expect(error.domain).to(equal(SQRLZipArchiverErrorDomain));
-	expect(@(error.code)).to(equal(@(SQRLZipArchiverShellTaskFailed)));
-	expect(error.userInfo[SQRLZipArchiverExitCodeErrorKey]).notTo(equal(0));
+	expect(error).notTo.beNil();
+	expect(error.domain).to.equal(SQRLZipArchiverErrorDomain);
+	expect(error.code).to.equal(SQRLZipArchiverShellTaskFailed);
+	expect(error.userInfo[SQRLZipArchiverExitCodeErrorKey]).notTo.equal(0);
 });
 
 it(@"should create a zip archive readable by itself", ^{
@@ -51,21 +45,21 @@ it(@"should create a zip archive readable by itself", ^{
 
 	NSError *error = nil;
 	BOOL success = [[SQRLZipArchiver createZipArchiveAtURL:zipURL fromDirectoryAtURL:self.testApplicationURL] asynchronouslyWaitUntilCompleted:&error];
-	expect(@(success)).to(beTruthy());
-	expect(error).to(beNil());
+	expect(success).to.beTruthy();
+	expect(error).to.beNil();
 
-	expect(@([NSFileManager.defaultManager fileExistsAtPath:zipURL.path])).to(beTruthy());
+	expect([NSFileManager.defaultManager fileExistsAtPath:zipURL.path]).to.beTruthy();
 
 	success = [[SQRLZipArchiver unzipArchiveAtURL:zipURL intoDirectoryAtURL:self.temporaryDirectoryURL] asynchronouslyWaitUntilCompleted:&error];
-	expect(@(success)).to(beTruthy());
-	expect(error).to(beNil());
+	expect(success).to.beTruthy();
+	expect(error).to.beNil();
 
 	NSURL *extractedAppURL = [self.temporaryDirectoryURL URLByAppendingPathComponent:@"TestApplication.app"];
-	expect(@([NSFileManager.defaultManager fileExistsAtPath:extractedAppURL.path])).to(beTruthy());
+	expect([NSFileManager.defaultManager fileExistsAtPath:extractedAppURL.path]).to.beTruthy();
 
 	success = [[self.testApplicationSignature verifyBundleAtURL:extractedAppURL] waitUntilCompleted:&error];
-	expect(@(success)).to(beTruthy());
-	expect(error).to(beNil());
+	expect(success).to.beTruthy();
+	expect(error).to.beNil();
 });
 
-QuickSpecEnd
+SpecEnd

SquirrelTests/SquirrelTests-Prefix.pch

@@ -0,0 +1,25 @@
+//
+//  SquirrelTests-Prefix.pch
+//  Squirrel
+//
+//  Created by Justin Spahr-Summers on 2013-07-21.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#ifdef __OBJC__
+	#import <Cocoa/Cocoa.h>
+	#import <SenTestingKit/SenTestingKit.h>
+
+	#import <Mantle/Mantle.h>
+	#import <ReactiveCocoa/ReactiveCocoa.h>
+	#import <ReactiveCocoa/EXTScope.h>
+	#import <Squirrel/Squirrel.h>
+
+	#define SPT_SUBCLASS SQRLTestCase
+	#import "Specta.h"
+
+	#define EXP_SHORTHAND
+	#import "Expecta.h"
+
+	#import "SQRLTestCase.h"
+#endif

SquirrelTests/SwiftSpec.swift

@@ -1,19 +0,0 @@
-//
-//  SwiftSpec.swift
-//  ReactiveCocoa
-//
-//  Created by Justin Spahr-Summers on 2014-10-14.
-//  Copyright (c) 2014 GitHub. All rights reserved.
-//
-
-import Foundation
-import Nimble
-import Quick
-
-// Without this, the Swift stdlib won't be linked into the test target (even if
-// “Embedded Content Contains Swift Code” is enabled).
-class SwiftSpec: QuickSpec {
-	override func spec() {
-		expect(true).to(beTruthy())
-	}
-}

SquirrelTests/en.lproj/InfoPlist.strings

@@ -0,0 +1,2 @@
+/* Localized versions of Info.plist keys */
+

TestApplication/TestAppConstants.h

@@ -1,22 +0,0 @@
-//
-//  TestAppConstants.h
-//  Squirrel
-//
-//  Created by Keith Duncan on 05/02/2014.
-//  Copyright (c) 2014 GitHub. All rights reserved.
-//
-
-#import <Foundation/Foundation.h>
-
-// This notification is posted to the distributed notification center when a
-// change to the `SQRLUpdater.state` property is observed.
-//
-// It is posted once on launch with the initial idle state, and then for any
-// transition thereafter.
-//
-// Yhe user info dictionary includes the new state value under the
-// `SQRLTestAppUpdaterStateKey` key.
-extern NSString * const SQRLTestAppUpdaterStateTransitionNotificationName;
-
-// The state of the updater, an NSNumber.
-extern NSString * const SQRLTestAppUpdaterStateKey;

TestApplication/TestAppConstants.m

@@ -1,13 +0,0 @@
-//
-//  TestAppConstants.m
-//  Squirrel
-//
-//  Created by Keith Duncan on 05/02/2014.
-//  Copyright (c) 2014 GitHub. All rights reserved.
-//
-
-#import "TestAppConstants.h"
-
-NSString * const SQRLTestAppUpdaterStateTransitionNotificationName = @"com.github.Squirrel.TestApplication.state-changed";
-
-NSString * const SQRLTestAppUpdaterStateKey = @"state";

TestApplication/TestAppDelegate.m

@@ -10,9 +10,9 @@
 #import "SQRLDirectoryManager.h"
 #import "SQRLShipItLauncher.h"
 #import "SQRLTestUpdate.h"
+#import "SQRLDownloadedUpdate.h"
 #import <ReactiveCocoa/EXTScope.h>
 #import <ReactiveCocoa/ReactiveCocoa.h>
-#import "TestAppConstants.h"
 
 @interface TestAppDelegate ()
 
@@ -64,12 +64,6 @@
 	self.updater = [[SQRLUpdater alloc] initWithUpdateRequest:request];
 	self.updater.updateClass = SQRLTestUpdate.class;
 
-	[RACObserve(self.updater, state) subscribeNext:^(NSNumber *state) {
-		NSLog(@"State transition: %@", state);
-
-		[NSDistributedNotificationCenter.defaultCenter postNotificationName:SQRLTestAppUpdaterStateTransitionNotificationName object:nil userInfo:@{ SQRLTestAppUpdaterStateKey: state }];
-	}];
-
 	__block NSUInteger updateCheckCount = 1;
 
 	[[[[[[[[[[RACSignal
@@ -77,18 +71,22 @@
 			NSLog(@"***** UPDATE CHECK %lu *****", (unsigned long)updateCheckCount);
 			updateCheckCount++;
 
-			return [self.updater.checkForUpdatesCommand execute:RACUnit.defaultUnit];
+			return [self.updater.checkForUpdatesAction deferred];
 		}]
 		doNext:^(SQRLDownloadedUpdate *update) {
 			NSLog(@"Got a candidate update: %@", update);
+
+			NSString *serialisedUpdate = [[NSString alloc] initWithData:[NSJSONSerialization dataWithJSONObject:[MTLJSONAdapter JSONDictionaryFromModel:update] options:0 error:NULL] encoding:NSUTF8StringEncoding];
+
+			[NSDistributedNotificationCenter.defaultCenter postNotificationName:@"com.github.Squirrel.TestApplication.updateReceived" object:nil userInfo:@{ @"update": serialisedUpdate }];
 		}]
 		// Retry until we get the expected release.
 		repeat]
-		skipUntilBlock:^(SQRLDownloadedUpdate *download) {
+		skipWhile:^ BOOL (SQRLDownloadedUpdate *download) {
 			SQRLTestUpdate *testUpdate = (id)download.update;
 			NSAssert([testUpdate isKindOfClass:SQRLTestUpdate.class], @"Unexpected update type: %@", testUpdate);
 
-			return testUpdate.final;
+			return !testUpdate.final;
 		}]
 		take:1]
 		doNext:^(id _) {
@@ -99,12 +97,12 @@
 			NSLog(@"Error in updater: %@", error);
 			return [RACSignal empty];
 		}]
-		then:^{
+		concat:[RACSignal defer:^{
 			NSString *delayString = NSProcessInfo.processInfo.environment[@"SQRLUpdateDelay"];
 			if (delayString == nil) return [RACSignal empty];
 
 			return [[RACSignal interval:delayString.doubleValue onScheduler:RACScheduler.mainThreadScheduler] take:1];
-		}]
+		}]]
 		subscribeCompleted:^{
 			[NSApp terminate:self];
 		}];

script/bootstrap

@@ -10,7 +10,7 @@ config ()
 {
     # A whitespace-separated list of executables that must be present and locatable.
     : ${REQUIRED_TOOLS="xctool"}
-
+    
     export REQUIRED_TOOLS
 }
 
@@ -28,14 +28,7 @@ main ()
         check_deps
     fi
 
-    local submodules=$(git submodule status)
-    local result=$?
-
-    if [ "$result" -ne "0" ]
-    then
-        exit $result
-    fi
-
+    local submodules=$(git submodule status 2>/dev/null)
     if [ -n "$submodules" ]
     then
         echo "*** Updating submodules..."

script/cibuild

@@ -44,7 +44,7 @@ config ()
     # A source-able file with information about the Keychain, containing our
     # code-signing certificate.
     : ${KEYCHAIN_INFO:=/var/lib/jenkins/config/xcodekeychain}
-
+    
     export XCWORKSPACE
     export XCODEPROJ
     export BOOTSTRAP
@@ -140,29 +140,18 @@ build_scheme ()
 
     local awkstatus=$?
 
-    if [ "$awkstatus" -eq "1" ]
-    then
-        # SDK not found, try for iphonesimulator.
-        sdkflag="-sdk iphonesimulator"
-
-        # Determine whether the unit tests will run with iphonesimulator
-        run_xctool $sdkflag -scheme "$scheme" run-tests | parse_build
-
-        awkstatus=$?
-
-        if [ "$awkstatus" -ne "0" ]
-        then
-            # Unit tests will not run on iphonesimulator.
-            sdkflag=""
-        fi
-    fi
-
     if [ "$awkstatus" -ne "0" ]
     then
         # Unit tests aren't supported.
         action=build
     fi
 
+    if [ "$awkstatus" -eq "1" ]
+    then
+        # Build for iOS.
+        sdkflag="-sdk iphonesimulator"
+    fi
+
     run_xctool $sdkflag -scheme "$scheme" $action
 }
 

script/deep-codesign

@@ -95,7 +95,7 @@ module Targets
 
 			# Look for an __TEXT,__info_plist section
 			# This contains the CFBundleIdentifier necessary for signing
-			`otool -l "#{path}"` =~ /__info_plist/
+			`otool -l #{path}` =~ /__info_plist/
 		end
 	end
 
@@ -106,10 +106,8 @@ end
 
 module Codesign
 	class Task
-		def self.sign(target, identity, timestamp)
-			arguments = [ "--sign", identity, "--force", "--preserve-metadata=identifier,entitlements,requirements", "--verbose", target.path ]
-			arguments.unshift("--timestamp=none") if not timestamp
-			codesign_with_arguments(arguments)
+		def self.sign(target, identity)
+			codesign_with_arguments([ "--sign", identity, "--force", "--preserve-metadata=identifier,entitlements,resource-rules,requirements", "--verbose", target.path ])
 		end
 
 		protected
@@ -139,7 +137,7 @@ unless build_dir && product_name
 	exit_error("Path to built product not provided")
 end
 
-input_path = File.realpath(File.join(build_dir, product_name))
+input_path = File.join(build_dir, product_name)
 unless File.exists?(input_path)
 	exit_error("Built product doesn't exist at path provided")
 end
@@ -170,7 +168,6 @@ while paths_to_search.size > 0
 
 		Dir.foreach(search_path) do |current_directory_entry|
 			next if current_directory_entry.start_with?(".")
-			File.delete(File.join(search_path, current_directory_entry)) if current_directory_entry.end_with?(".cstemp")
 
 			target = match_path(File.join(search_path, current_directory_entry))
 			next if target.nil?
@@ -196,8 +193,7 @@ targets = targets.sort_by do |target|
 end
 targets.reverse!
 
-use_timestamp = ENV["CONFIGURATION"] == "Release"
 targets.each do |target|
 	puts "=> #{target.path}"
-	Codesign::Task.sign(target, codesign_identity, use_timestamp)
+	Codesign::Task.sign(target, codesign_identity)
 end

script/schemes.awk

@@ -2,8 +2,10 @@ BEGIN {
     FS = "\n";
 }
 
-/Schemes:/ {
+/Targets:/ {
     while (getline && $0 != "") {
+        if ($0 ~ /Test/) continue;
+
         sub(/^ +/, "");
         print "'" $0 "'";
     }