Move all the error codes into one domain

Squirrel.xcodeproj/project.pbxproj

@@ -16,6 +16,9 @@
 		53710D7417D8F59700A992DE /* SQRLDeepCodesignSpec.m in Sources */ = {isa = PBXBuildFile; fileRef = 53710D7317D8F59700A992DE /* SQRLDeepCodesignSpec.m */; };
 		53710D8417D8F5CB00A992DE /* deep-codesign in Resources */ = {isa = PBXBuildFile; fileRef = 53710D7F17D8F5C300A992DE /* deep-codesign */; };
 		5395C0E317E9D013001648E8 /* SQRLUpdateSpec.m in Sources */ = {isa = PBXBuildFile; fileRef = 5395C0E217E9D013001648E8 /* SQRLUpdateSpec.m */; };
+		53A60408182134F9002DB2C7 /* Squirrel-Constants.h in Headers */ = {isa = PBXBuildFile; fileRef = 53A60406182134F9002DB2C7 /* Squirrel-Constants.h */; settings = {ATTRIBUTES = (Public, ); }; };
+		53A60409182134F9002DB2C7 /* Squirrel-Constants.m in Sources */ = {isa = PBXBuildFile; fileRef = 53A60407182134F9002DB2C7 /* Squirrel-Constants.m */; };
+		53A6040A182134F9002DB2C7 /* Squirrel-Constants.m in Sources */ = {isa = PBXBuildFile; fileRef = 53A60407182134F9002DB2C7 /* Squirrel-Constants.m */; };
 		53AACF4B17E9CA0500B41027 /* SQRLUpdate.h in Headers */ = {isa = PBXBuildFile; fileRef = 53AACF4917E9CA0500B41027 /* SQRLUpdate.h */; settings = {ATTRIBUTES = (Public, ); }; };
 		53AACF4C17E9CA0500B41027 /* SQRLUpdate.m in Sources */ = {isa = PBXBuildFile; fileRef = 53AACF4A17E9CA0500B41027 /* SQRLUpdate.m */; };
 		D000218F17BACEFF0050109A /* SQRLZipArchiver.m in Sources */ = {isa = PBXBuildFile; fileRef = D000218D17BACEFF0050109A /* SQRLZipArchiver.m */; };
@@ -391,6 +394,8 @@
 		53710D8217D8F5C300A992DE /* targets.awk */ = {isa = PBXFileReference; lastKnownFileType = text; path = targets.awk; sourceTree = "<group>"; };
 		53710D8317D8F5C300A992DE /* xcodebuild.awk */ = {isa = PBXFileReference; lastKnownFileType = text; path = xcodebuild.awk; sourceTree = "<group>"; };
 		5395C0E217E9D013001648E8 /* SQRLUpdateSpec.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SQRLUpdateSpec.m; sourceTree = "<group>"; };
+		53A60406182134F9002DB2C7 /* Squirrel-Constants.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "Squirrel-Constants.h"; sourceTree = "<group>"; };
+		53A60407182134F9002DB2C7 /* Squirrel-Constants.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "Squirrel-Constants.m"; sourceTree = "<group>"; };
 		53AACF4917E9CA0500B41027 /* SQRLUpdate.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SQRLUpdate.h; sourceTree = "<group>"; };
 		53AACF4A17E9CA0500B41027 /* SQRLUpdate.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = SQRLUpdate.m; sourceTree = "<group>"; };
 		D000218C17BACEFF0050109A /* SQRLZipArchiver.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = SQRLZipArchiver.h; sourceTree = "<group>"; };
@@ -591,6 +596,15 @@
 			path = script;
 			sourceTree = "<group>";
 		};
+		53A603F7182134D3002DB2C7 /* Supporting Files */ = {
+			isa = PBXGroup;
+			children = (
+				53A60406182134F9002DB2C7 /* Squirrel-Constants.h */,
+				53A60407182134F9002DB2C7 /* Squirrel-Constants.m */,
+			);
+			name = "Supporting Files";
+			sourceTree = "<group>";
+		};
 		D00F5B8217E82CFB009A4818 /* Extensions */ = {
 			isa = PBXGroup;
 			children = (
@@ -705,9 +719,9 @@
 			isa = PBXGroup;
 			children = (
 				D0A56BA41804B1FD00A84EDC /* Mantle.framework */,
-				D0A56BA61804B1FD00A84EDC /* Mantle Mac Tests.octest */,
+				D0A56BA61804B1FD00A84EDC /* Mantle Tests.octest */,
 				D0A56BA81804B1FD00A84EDC /* libMantle-iOS.a */,
-				D0A56BAA1804B1FD00A84EDC /* Mantle iOS Tests.octest */,
+				D0A56BAA1804B1FD00A84EDC /* Mantle-iOS Tests.octest */,
 				D0A56BAC1804B1FD00A84EDC /* libMantle-Mac.a */,
 			);
 			name = Products;
@@ -926,6 +940,7 @@
 				D0A56BF61804BABB00A84EDC /* Code Signing */,
 				D0A56BE71804BA2400A84EDC /* State */,
 				D06B58BC18032BE800656D97 /* Transactions */,
+				53A603F7182134D3002DB2C7 /* Supporting Files */,
 			);
 			name = Shared;
 			path = Squirrel;
@@ -979,6 +994,7 @@
 				D0C22C52179CC23900158214 /* Squirrel.h in Headers */,
 				D0964B3817F2E01500D88BF7 /* SQRLDownloadedUpdate.h in Headers */,
 				53AACF4B17E9CA0500B41027 /* SQRLUpdate.h in Headers */,
+				53A60408182134F9002DB2C7 /* Squirrel-Constants.h in Headers */,
 				D00F5B8B17E82D15009A4818 /* NSProcessInfo+SQRLVersionExtensions.h in Headers */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -1153,10 +1169,9 @@
 			remoteRef = D0A56BA31804B1FD00A84EDC /* PBXContainerItemProxy */;
 			sourceTree = BUILT_PRODUCTS_DIR;
 		};
-		D0A56BA61804B1FD00A84EDC /* Mantle Mac Tests.octest */ = {
+		D0A56BA61804B1FD00A84EDC /* Mantle Tests.octest */ = {
 			isa = PBXReferenceProxy;
 			fileType = wrapper.cfbundle;
-			name = "Mantle Mac Tests.octest";
 			path = "Mantle Tests.octest";
 			remoteRef = D0A56BA51804B1FD00A84EDC /* PBXContainerItemProxy */;
 			sourceTree = BUILT_PRODUCTS_DIR;
@@ -1168,10 +1183,9 @@
 			remoteRef = D0A56BA71804B1FD00A84EDC /* PBXContainerItemProxy */;
 			sourceTree = BUILT_PRODUCTS_DIR;
 		};
-		D0A56BAA1804B1FD00A84EDC /* Mantle iOS Tests.octest */ = {
+		D0A56BAA1804B1FD00A84EDC /* Mantle-iOS Tests.octest */ = {
 			isa = PBXReferenceProxy;
 			fileType = wrapper.cfbundle;
-			name = "Mantle iOS Tests.octest";
 			path = "Mantle-iOS Tests.octest";
 			remoteRef = D0A56BA91804B1FD00A84EDC /* PBXContainerItemProxy */;
 			sourceTree = BUILT_PRODUCTS_DIR;
@@ -1361,6 +1375,7 @@
 				D014AC0517B97885007D79D0 /* ShipIt-main.m in Sources */,
 				D014AC1917B979A8007D79D0 /* SQRLCodeSignature.m in Sources */,
 				D06B58B618032B1500656D97 /* RACSignal+SQRLTransactionExtensions.m in Sources */,
+				53A6040A182134F9002DB2C7 /* Squirrel-Constants.m in Sources */,
 				D014AC1A17B979AA007D79D0 /* NSError+SQRLVerbosityExtensions.m in Sources */,
 				D0D2B6271804E903000EA901 /* SQRLDirectoryManager.m in Sources */,
 				D0964B3E17F2E20B00D88BF7 /* NSBundle+SQRLVersionExtensions.m in Sources */,
@@ -1391,6 +1406,7 @@
 				D0EDBE9D17B0C68E0058BC3C /* NSError+SQRLVerbosityExtensions.m in Sources */,
 				53AACF4C17E9CA0500B41027 /* SQRLUpdate.m in Sources */,
 				D0A56BEB1804BA3C00A84EDC /* SQRLShipItState.m in Sources */,
+				53A60409182134F9002DB2C7 /* Squirrel-Constants.m in Sources */,
 				D00F5B8C17E82D15009A4818 /* NSProcessInfo+SQRLVersionExtensions.m in Sources */,
 				D06B58B518032B1500656D97 /* RACSignal+SQRLTransactionExtensions.m in Sources */,
 			);

Squirrel/SQRLCodeSignature.h

@@ -9,16 +9,6 @@
 #import <Foundation/Foundation.h>
 #import <Mantle/Mantle.h>
 
-// The domain for errors originating within SQRLCodeSignature.
-extern NSString * const SQRLCodeSignatureErrorDomain;
-
-// The bundle did not pass codesign verification.
-extern const NSInteger SQRLCodeSignatureErrorDidNotPass;
-
-// A static code object could not be created for the target bundle or running
-// code.
-extern const NSInteger SQRLCodeSignatureErrorCouldNotCreateStaticCode;
-
 @class RACSignal;
 
 // Implements the verification of Apple code signatures.

Squirrel/SQRLCodeSignature.m

@@ -10,11 +10,7 @@
 #import <ReactiveCocoa/EXTScope.h>
 #import <ReactiveCocoa/ReactiveCocoa.h>
 #import <Security/Security.h>
-
-NSString * const SQRLCodeSignatureErrorDomain = @"SQRLCodeSignatureErrorDomain";
-
-const NSInteger SQRLCodeSignatureErrorDidNotPass = -1;
-const NSInteger SQRLCodeSignatureErrorCouldNotCreateStaticCode = -2;
+#import "Squirrel-Constants.h"
 
 @interface SQRLCodeSignature ()
 
@@ -99,7 +95,7 @@ const NSInteger SQRLCodeSignatureErrorCouldNotCreateStaticCode = -2;
 			NSString *failureReason = CFBridgingRelease(SecCopyErrorMessageString(result, NULL));
 			if (failureReason != nil) userInfo[NSLocalizedFailureReasonErrorKey] = failureReason;
 			
-			[subscriber sendError:[NSError errorWithDomain:SQRLCodeSignatureErrorDomain code:SQRLCodeSignatureErrorCouldNotCreateStaticCode userInfo:userInfo]];
+			[subscriber sendError:[NSError errorWithDomain:SQRLErrorDomain code:SQRLCodeSignatureErrorCouldNotCreateStaticCode userInfo:userInfo]];
 			return nil;
 		}
 		
@@ -118,7 +114,7 @@ const NSInteger SQRLCodeSignatureErrorCouldNotCreateStaticCode = -2;
 			if (failureReason != nil) userInfo[NSLocalizedFailureReasonErrorKey] = failureReason;
 			if (validityError != NULL) userInfo[NSUnderlyingErrorKey] = (__bridge NSError *)validityError;
 			
-			[subscriber sendError:[NSError errorWithDomain:SQRLCodeSignatureErrorDomain code:SQRLCodeSignatureErrorDidNotPass userInfo:userInfo]];
+			[subscriber sendError:[NSError errorWithDomain:SQRLErrorDomain code:SQRLCodeSignatureErrorDidNotPass userInfo:userInfo]];
 			return nil;
 		}
 		

Squirrel/SQRLInstaller.h

@@ -8,9 +8,6 @@
 
 #import <Foundation/Foundation.h>
 
-// The domain for errors originating within SQRLInstaller.
-extern NSString * const SQRLInstallerErrorDomain;
-
 // There was an error copying the target bundle to the backup location.
 extern const NSInteger SQRLInstallerErrorBackupFailed;
 

Squirrel/SQRLInstaller.m

@@ -18,8 +18,7 @@
 #import <ReactiveCocoa/EXTScope.h>
 #import <ReactiveCocoa/ReactiveCocoa.h>
 #import <sys/xattr.h>
-
-NSString * const SQRLInstallerErrorDomain = @"SQRLInstallerErrorDomain";
+#import "Squirrel-Constants.h"
 
 const NSInteger SQRLInstallerErrorBackupFailed = -1;
 const NSInteger SQRLInstallerErrorReplacingTarget = -2;
@@ -236,7 +235,7 @@ typedef struct {
 				NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"Try installing the update again.", nil)
 			};
 
-			return [RACSignal error:[NSError errorWithDomain:SQRLInstallerErrorDomain code:SQRLInstallerErrorInvalidState userInfo:userInfo]];
+			return [RACSignal error:[NSError errorWithDomain:SQRLErrorDomain code:SQRLInstallerErrorInvalidState userInfo:userInfo]];
 		}
 
 		SEL selector = dispatchTable[tableIndex].selector;
@@ -619,7 +618,7 @@ typedef struct {
 		NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"Try installing the update again.", nil)
 	};
 
-	return [NSError errorWithDomain:SQRLInstallerErrorDomain code:SQRLInstallerErrorMissingInstallationData userInfo:userInfo];
+	return [NSError errorWithDomain:SQRLErrorDomain code:SQRLInstallerErrorMissingInstallationData userInfo:userInfo];
 }
 
 - (NSError *)errorByAddingDescription:(NSString *)description code:(NSInteger)code toError:(NSError *)error {
@@ -628,7 +627,7 @@ typedef struct {
 	if (description != nil) userInfo[NSLocalizedDescriptionKey] = description;
 	if (error != nil) userInfo[NSUnderlyingErrorKey] = error;
 
-	return [NSError errorWithDomain:SQRLInstallerErrorDomain code:code userInfo:userInfo];
+	return [NSError errorWithDomain:SQRLErrorDomain code:code userInfo:userInfo];
 }
 
 @end

Squirrel/SQRLShipItLauncher.h

@@ -10,12 +10,6 @@
 
 @class RACSignal;
 
-// The domain for errors originating within SQRLShipItLauncher.
-extern NSString * const SQRLShipItLauncherErrorDomain;
-
-// The ShipIt service could not be started.
-extern const NSInteger SQRLShipItLauncherErrorCouldNotStartService;
-
 // Responsible for launching the ShipIt service to actually install an update.
 @interface SQRLShipItLauncher : NSObject
 

Squirrel/SQRLShipItLauncher.m

@@ -13,10 +13,7 @@
 #import <Security/Security.h>
 #import <ServiceManagement/ServiceManagement.h>
 #import <launch.h>
-
-NSString * const SQRLShipItLauncherErrorDomain = @"SQRLShipItLauncherErrorDomain";
-
-const NSInteger SQRLShipItLauncherErrorCouldNotStartService = 1;
+#import "Squirrel-Constants.h"
 
 @implementation SQRLShipItLauncher
 

Squirrel/SQRLShipItState.h

@@ -8,22 +8,6 @@
 
 #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;

Squirrel/SQRLShipItState.m

@@ -8,14 +8,10 @@
 
 #import "SQRLShipItState.h"
 #import <ReactiveCocoa/ReactiveCocoa.h>
+#import "Squirrel-Constants.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
@@ -33,7 +29,7 @@ const NSInteger SQRLShipItStateErrorArchiving = 3;
 				NSLocalizedRecoverySuggestionErrorKey: [NSString stringWithFormat:NSLocalizedString(@"\"%@\" must not be set to nil.", nil), key]
 			};
 
-			*error = [NSError errorWithDomain:SQRLShipItStateErrorDomain code:SQRLShipItStateErrorMissingRequiredProperty userInfo:userInfo];
+			*error = [NSError errorWithDomain:SQRLErrorDomain code:SQRLShipItStateErrorMissingRequiredProperty userInfo:userInfo];
 		}
 
 		return NO;
@@ -78,7 +74,7 @@ const NSInteger SQRLShipItStateErrorArchiving = 3;
 					NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"An unknown error occurred while unarchiving.", nil)
 				};
 
-				return [RACSignal error:[NSError errorWithDomain:SQRLShipItStateErrorDomain code:SQRLShipItStateErrorUnarchiving userInfo:userInfo]];
+				return [RACSignal error:[NSError errorWithDomain:SQRLErrorDomain code:SQRLShipItStateErrorUnarchiving userInfo:userInfo]];
 			}
 
 			return [RACSignal return:state];
@@ -97,7 +93,7 @@ const NSInteger SQRLShipItStateErrorArchiving = 3;
 				NSLocalizedRecoverySuggestionErrorKey: NSLocalizedString(@"An unknown error occurred while archiving.", nil)
 			};
 
-			return [RACSignal error:[NSError errorWithDomain:SQRLShipItStateErrorDomain code:SQRLShipItStateErrorArchiving userInfo:userInfo]];
+			return [RACSignal error:[NSError errorWithDomain:SQRLErrorDomain code:SQRLShipItStateErrorArchiving userInfo:userInfo]];
 		}
 
 		return [RACSignal return:data];

Squirrel/SQRLUpdater.h

@@ -6,30 +6,6 @@
 //  Copyright (c) 2013 GitHub. All rights reserved.
 //
 
-// The domain for errors originating within SQRLUpdater.
-extern NSString * const SQRLUpdaterErrorDomain;
-
-// The downloaded update does not contain an app bundle, or it was deleted on
-// disk before we could get to it.
-extern const NSInteger SQRLUpdaterErrorMissingUpdateBundle;
-
-// An error occurred in the out-of-process updater while it was setting up.
-extern const NSInteger SQRLUpdaterErrorPreparingUpdateJob;
-
-// The code signing requirement for the running application could not be
-// retrieved.
-extern const NSInteger SQRLUpdaterErrorRetrievingCodeSigningRequirement;
-
-// The server sent a response that we didn't understand.
-//
-// Includes `SQRLUpdaterServerDataErrorKey` in the error's `userInfo`.
-extern const NSInteger SQRLUpdaterErrorInvalidServerResponse;
-
-// The server sent update JSON that we didn't understand.
-//
-// Includes `SQRLUpdaterJSONObjectErrorKey` in the error's `userInfo`.
-extern const NSInteger SQRLUpdaterErrorInvalidJSON;
-
 // Associated with the `NSData` received from the server when an error with code
 // `SQRLUpdaterErrorInvalidServerResponse` is generated.
 extern NSString * const SQRLUpdaterServerDataErrorKey;

Squirrel/SQRLUpdater.m

@@ -20,17 +20,11 @@
 #import "SQRLZipArchiver.h"
 #import <ReactiveCocoa/EXTScope.h>
 #import <ReactiveCocoa/ReactiveCocoa.h>
+#import "Squirrel-Constants.h"
 
-NSString * const SQRLUpdaterErrorDomain = @"SQRLUpdaterErrorDomain";
 NSString * const SQRLUpdaterServerDataErrorKey = @"SQRLUpdaterServerDataErrorKey";
 NSString * const SQRLUpdaterJSONObjectErrorKey = @"SQRLUpdaterJSONObjectErrorKey";
 
-const NSInteger SQRLUpdaterErrorMissingUpdateBundle = 2;
-const NSInteger SQRLUpdaterErrorPreparingUpdateJob = 3;
-const NSInteger SQRLUpdaterErrorRetrievingCodeSigningRequirement = 4;
-const NSInteger SQRLUpdaterErrorInvalidServerResponse = 5;
-const NSInteger SQRLUpdaterErrorInvalidJSON = 6;
-
 @interface SQRLUpdater ()
 
 // The code signature for the running application, used to check updates before
@@ -222,7 +216,7 @@ const NSInteger SQRLUpdaterErrorInvalidJSON = 6;
 				userInfo[SQRLUpdaterServerDataErrorKey] = data;
 				if (error != nil) userInfo[NSUnderlyingErrorKey] = error;
 
-				return [RACSignal error:[NSError errorWithDomain:SQRLUpdaterErrorDomain code:SQRLUpdaterErrorInvalidServerResponse userInfo:userInfo]];
+				return [RACSignal error:[NSError errorWithDomain:SQRLErrorDomain code:SQRLUpdaterErrorInvalidServerResponse userInfo:userInfo]];
 			}
 
 			Class updateClass = self.updateClass;
@@ -239,7 +233,7 @@ const NSInteger SQRLUpdaterErrorInvalidJSON = 6;
 				userInfo[SQRLUpdaterJSONObjectErrorKey] = JSON;
 				if (error != nil) userInfo[NSUnderlyingErrorKey] = error;
 
-				return [RACSignal error:[NSError errorWithDomain:SQRLUpdaterErrorDomain code:SQRLUpdaterErrorInvalidJSON userInfo:userInfo]];
+				return [RACSignal error:[NSError errorWithDomain:SQRLErrorDomain code:SQRLUpdaterErrorInvalidJSON userInfo:userInfo]];
 			}
 
 			return [RACSignal return:update];
@@ -375,7 +369,7 @@ const NSInteger SQRLUpdaterErrorInvalidJSON = 6;
 					NSLocalizedDescriptionKey: [NSString stringWithFormat:NSLocalizedString(@"Could not locate update bundle for %@ within %@", nil), NSRunningApplication.currentApplication.bundleIdentifier, directory],
 				};
 
-				return [RACSignal error:[NSError errorWithDomain:SQRLUpdaterErrorDomain code:SQRLUpdaterErrorMissingUpdateBundle userInfo:userInfo]];
+				return [RACSignal error:[NSError errorWithDomain:SQRLErrorDomain code:SQRLUpdaterErrorMissingUpdateBundle userInfo:userInfo]];
 			}
 		}]
 		map:^(NSURL *URL) {
@@ -423,7 +417,7 @@ const NSInteger SQRLUpdaterErrorInvalidJSON = 6;
 							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 error:[NSError errorWithDomain:SQRLErrorDomain code:SQRLUpdaterErrorPreparingUpdateJob userInfo:userInfo]];
 					}
 
 					return [RACSignal empty];

Squirrel/SQRLZipArchiver.h

@@ -10,17 +10,10 @@
 
 @class RACSignal;
 
-extern NSString * const SQRLZipArchiverErrorDomain;
-
 // Associated with an NSNumber containing the code that a shell task exited
 // with.
 extern NSString * const SQRLZipArchiverExitCodeErrorKey;
 
-// `SQRLZipArchiver` tried to invoke the shell and failed.
-//
-// Contains `SQRLZipArchiverExitStatusErrorKey` in the `userInfo` dictionary.
-extern const NSInteger SQRLZipArchiverShellTaskFailed;
-
 // Uses `ditto` on the command line to zip and unzip archives.
 @interface SQRLZipArchiver : NSObject
 

Squirrel/SQRLZipArchiver.m

@@ -9,10 +9,9 @@
 #import "SQRLZipArchiver.h"
 #import <ReactiveCocoa/EXTScope.h>
 #import <ReactiveCocoa/ReactiveCocoa.h>
+#import "Squirrel-Constants.h"
 
-NSString * const SQRLZipArchiverErrorDomain = @"SQRLZipArchiverErrorDomain";
 NSString * const SQRLZipArchiverExitCodeErrorKey = @"SQRLZipArchiverExitCodeErrorKey";
-const NSInteger SQRLZipArchiverShellTaskFailed = 1;
 
 @interface SQRLZipArchiver () {
 	RACSubject *_taskTerminated;
@@ -143,7 +142,7 @@ const NSInteger SQRLZipArchiverShellTaskFailed = 1;
 					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:SQRLErrorDomain code:SQRLZipArchiverShellTaskFailed userInfo:userInfo]];
 				}];
 		}]
 		take:1]

Squirrel/ShipIt-main.m

@@ -24,9 +24,6 @@
 // updating will abort.
 static const NSUInteger SQRLShipItMaximumInstallationAttempts = 3;
 
-// The domain for errors generated here.
-static NSString * const SQRLShipItErrorDomain = @"SQRLShipItErrorDomain";
-
 // Waits for all instances of the target application (as described in the
 // `state`) to exit, then sends completed.
 static RACSignal *waitForTerminationIfNecessary(SQRLShipItState *state) {

Squirrel/Squirrel-Constants.h

@@ -0,0 +1,71 @@
+//
+//  Squirrel-Constants.h
+//  Squirrel
+//
+//  Created by Keith Duncan on 30/10/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+// Error domain for errors originating in Squirrel.
+extern NSString * const SQRLErrorDomain;
+
+// Error codes for errors originating in Squirrel.
+//
+// SQRLCodeSignatureErrorDidNotPass - The bundle did not pass codesign
+// verification.
+//
+// SQRLCodeSignatureErrorCouldNotCreateStaticCode - A static code object could
+// not be created for the target bundle or running code.
+//
+// SQRLShipItStateErrorMissingRequiredProperty - A required property was `nil`
+// upon initialization. Includes `SQRLShipItStatePropertyErrorKey` in the
+// error's `userInfo` dictionary.
+//
+// SQRLShipItStateErrorUnarchiving - The saved state on disk could not be
+// unarchived, possibly because it's invalid.
+//
+// SQRLShipItStateErrorArchiving - The state object could not be archived.
+//
+// SQRLUpdaterErrorMissingUpdateBundle - The downloaded update does not contain
+// an app bundle, or it was deleted on disk before we could get to it.
+//
+// SQRLUpdaterErrorPreparingUpdateJob - An error occurred in the out-of-process
+// updater while it was setting up.
+//
+// SQRLUpdaterErrorRetrievingCodeSigningRequirement - The code signing
+// requirement for the running application could not be retrieved.
+//
+// SQRLUpdaterErrorInvalidServerResponse - The server sent a response that we
+// didn't understand. Includes `SQRLUpdaterServerDataErrorKey` in the error's
+// `userInfo` dictionary.
+//
+// SQRLUpdaterErrorInvalidJSON - The server sent update JSON that we didn't
+// understand. Includes `SQRLUpdaterJSONObjectErrorKey` in the error's
+// `userInfo` dictionary.
+//
+// SQRLZipArchiverShellTaskFailed - `SQRLZipArchiver` tried to invoke the shell
+// and failed. Includes `SQRLZipArchiverExitStatusErrorKey` in the error's
+// `userInfo` dictionary.
+//
+// SQRLShipItLauncherErrorCouldNotStartService - The ShipIt service could not be
+// started.
+typedef enum : NSInteger {
+	SQRLCodeSignatureErrorDidNotPass = -1,
+	SQRLCodeSignatureErrorCouldNotCreateStaticCode = -2,
+
+	SQRLShipItStateErrorMissingRequiredProperty = -100,
+	SQRLShipItStateErrorUnarchiving = -101,
+	SQRLShipItStateErrorArchiving = -102,
+
+	SQRLUpdaterErrorMissingUpdateBundle = -200,
+	SQRLUpdaterErrorPreparingUpdateJob = -201,
+	SQRLUpdaterErrorRetrievingCodeSigningRequirement = -202,
+	SQRLUpdaterErrorInvalidServerResponse = -203,
+	SQRLUpdaterErrorInvalidJSON = -204,
+
+	SQRLZipArchiverShellTaskFailed = -300,
+
+	SQRLShipItLauncherErrorCouldNotStartService = -400,
+} SQRLErrorCode;

Squirrel/Squirrel-Constants.m

@@ -0,0 +1,11 @@
+//
+//  Squirrel-Constants.m
+//  Squirrel
+//
+//  Created by Keith Duncan on 30/10/2013.
+//  Copyright (c) 2013 GitHub. All rights reserved.
+//
+
+#import "Squirrel-Constants.h"
+
+NSString * const SQRLErrorDomain = @"SQRLErrorDomain";

SquirrelTests/SQRLCodeSignatureVerifierSpec.m

@@ -7,6 +7,7 @@
 //
 
 #import "SQRLCodeSignature.h"
+#import "Squirrel-Constants.h"
 
 SpecBegin(SQRLCodeSignature)
 
@@ -54,7 +55,7 @@ describe(@"code signature changes", ^{
 		expect(success).to.beFalsy();
 
 		expect(error).notTo.beNil();
-		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.domain).to.equal(SQRLErrorDomain);
 		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 
@@ -66,7 +67,7 @@ describe(@"code signature changes", ^{
 		expect(success).to.beFalsy();
 
 		expect(error).notTo.beNil();
-		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.domain).to.equal(SQRLErrorDomain);
 		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 });
@@ -80,7 +81,7 @@ describe(@"main executable changes", ^{
 		expect(success).to.beFalsy();
 
 		expect(error).notTo.beNil();
-		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.domain).to.equal(SQRLErrorDomain);
 		expect(error.code).to.equal(SQRLCodeSignatureErrorCouldNotCreateStaticCode);
 	});
 
@@ -92,7 +93,7 @@ describe(@"main executable changes", ^{
 		expect(success).to.beFalsy();
 
 		expect(error).notTo.beNil();
-		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.domain).to.equal(SQRLErrorDomain);
 		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 });
@@ -113,7 +114,7 @@ describe(@"helper executable changes", ^{
 		expect(success).to.beFalsy();
 
 		expect(error).notTo.beNil();
-		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.domain).to.equal(SQRLErrorDomain);
 		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 
@@ -125,7 +126,7 @@ describe(@"helper executable changes", ^{
 		expect(success).to.beFalsy();
 
 		expect(error).notTo.beNil();
-		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.domain).to.equal(SQRLErrorDomain);
 		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 });
@@ -146,7 +147,7 @@ describe(@"resource changes", ^{
 		expect(success).to.beFalsy();
 
 		expect(error).notTo.beNil();
-		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.domain).to.equal(SQRLErrorDomain);
 		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 
@@ -158,7 +159,7 @@ describe(@"resource changes", ^{
 		expect(success).to.beFalsy();
 
 		expect(error).notTo.beNil();
-		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.domain).to.equal(SQRLErrorDomain);
 		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 });
@@ -178,7 +179,7 @@ describe(@"framework changes", ^{
 		expect(success).to.beFalsy();
 
 		expect(error).notTo.beNil();
-		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.domain).to.equal(SQRLErrorDomain);
 		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 
@@ -190,7 +191,7 @@ describe(@"framework changes", ^{
 		expect(success).to.beFalsy();
 
 		expect(error).notTo.beNil();
-		expect(error.domain).to.equal(SQRLCodeSignatureErrorDomain);
+		expect(error.domain).to.equal(SQRLErrorDomain);
 		expect(error.code).to.equal(SQRLCodeSignatureErrorDidNotPass);
 	});
 });

SquirrelTests/SQRLZipArchiverSpec.m

@@ -8,6 +8,7 @@
 
 #import "SQRLCodeSignature.h"
 #import "SQRLZipArchiver.h"
+#import "Squirrel-Constants.h"
 
 SpecBegin(SQRLZipArchiver)
 
@@ -35,7 +36,7 @@ it(@"should fail to extract a nonexistent zip archive", ^{
 	NSLog(@"%@", error);
 
 	expect(error).notTo.beNil();
-	expect(error.domain).to.equal(SQRLZipArchiverErrorDomain);
+	expect(error.domain).to.equal(SQRLErrorDomain);
 	expect(error.code).to.equal(SQRLZipArchiverShellTaskFailed);
 	expect(error.userInfo[SQRLZipArchiverExitCodeErrorKey]).notTo.equal(0);
 });