From ca5d243ca7afdad7c51cb9378ccf44b1663fcd06 Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <drosen@microsoft.com>
Date: Wed, 17 Dec 2014 15:49:00 -0800
Subject: [PATCH 01/11] Added test from original issue.

---
 ...leWithPriorUninstantiatedModule.errors.txt | 21 ++++++++++++
 .../cloduleWithPriorUninstantiatedModule.js   | 33 +++++++++++++++++++
 .../cloduleWithPriorUninstantiatedModule.ts   | 15 +++++++++
 3 files changed, 69 insertions(+)
 create mode 100644 tests/baselines/reference/cloduleWithPriorUninstantiatedModule.errors.txt
 create mode 100644 tests/baselines/reference/cloduleWithPriorUninstantiatedModule.js
 create mode 100644 tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts

diff --git a/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.errors.txt b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.errors.txt
new file mode 100644
index 00000000000..cae69212f2f
--- /dev/null
+++ b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.errors.txt
@@ -0,0 +1,21 @@
+tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts(2,8): error TS2434: A module declaration cannot be located prior to a class or function with which it is merged
+
+
+==== tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts (1 errors) ====
+    // Ambient/uninstantiated module.
+    module Moclodule {
+           ~~~~~~~~~
+!!! error TS2434: A module declaration cannot be located prior to a class or function with which it is merged
+        export interface Someinterface {
+            foo(): void;
+        }
+    }
+    
+    class Moclodule {
+    }
+    
+    // Instantiated module.
+    module Moclodule {
+        export class Manager {
+        }
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.js b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.js
new file mode 100644
index 00000000000..37bfb617375
--- /dev/null
+++ b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.js
@@ -0,0 +1,33 @@
+//// [cloduleWithPriorUninstantiatedModule.ts]
+// Ambient/uninstantiated module.
+module Moclodule {
+    export interface Someinterface {
+        foo(): void;
+    }
+}
+
+class Moclodule {
+}
+
+// Instantiated module.
+module Moclodule {
+    export class Manager {
+    }
+}
+
+//// [cloduleWithPriorUninstantiatedModule.js]
+var Moclodule = (function () {
+    function Moclodule() {
+    }
+    return Moclodule;
+})();
+// Instantiated module.
+var Moclodule;
+(function (Moclodule) {
+    var Manager = (function () {
+        function Manager() {
+        }
+        return Manager;
+    })();
+    Moclodule.Manager = Manager;
+})(Moclodule || (Moclodule = {}));
diff --git a/tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts b/tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts
new file mode 100644
index 00000000000..8c9c646b687
--- /dev/null
+++ b/tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts
@@ -0,0 +1,15 @@
+// Ambient/uninstantiated module.
+module Moclodule {
+    export interface Someinterface {
+        foo(): void;
+    }
+}
+
+class Moclodule {
+}
+
+// Instantiated module.
+module Moclodule {
+    export class Manager {
+    }
+}
\ No newline at end of file

From fac52017653a97a2c95013b76c8d62a55bf228a7 Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <drosen@microsoft.com>
Date: Wed, 17 Dec 2014 17:00:42 -0800
Subject: [PATCH 02/11] Only error on non-ambient instantiated modules
 preceding clodules.

---
 src/compiler/checker.ts                       |  9 ++++++-
 src/compiler/emitter.ts                       |  4 +--
 src/compiler/utilities.ts                     |  6 +++++
 ...leWithPriorUninstantiatedModule.errors.txt | 21 ----------------
 ...cloduleWithPriorUninstantiatedModule.types | 25 +++++++++++++++++++
 5 files changed, 41 insertions(+), 24 deletions(-)
 delete mode 100644 tests/baselines/reference/cloduleWithPriorUninstantiatedModule.errors.txt
 create mode 100644 tests/baselines/reference/cloduleWithPriorUninstantiatedModule.types

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index ccc67ba3881..e5334c454d3 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -9003,7 +9003,12 @@ module ts {
                 checkCollisionWithRequireExportsInGeneratedCode(node, node.name);
                 checkExportsOnMergedDeclarations(node);
                 var symbol = getSymbolOfNode(node);
-                if (symbol.flags & SymbolFlags.ValueModule && symbol.declarations.length > 1 && !isInAmbientContext(node)) {
+
+                // The following checks only apply on a non-ambient instantiated module declaration.
+                if (symbol.flags & SymbolFlags.ValueModule
+                    && symbol.declarations.length > 1
+                    && !isInAmbientContext(node)
+                    && isInstantiatedModule(node, compilerOptions.preserveConstEnums)) {
                     var classOrFunc = getFirstNonAmbientClassOrFunctionDeclaration(symbol);
                     if (classOrFunc) {
                         if (getSourceFileOfNode(node) !== getSourceFileOfNode(classOrFunc)) {
@@ -9014,6 +9019,8 @@ module ts {
                         }
                     }
                 }
+
+                // Checks for ambient external modules.
                 if (node.name.kind === SyntaxKind.StringLiteral) {
                     if (!isGlobalSourceFile(node.parent)) {
                         error(node.name, Diagnostics.Ambient_external_modules_cannot_be_nested_in_other_modules);
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index b713fddf676..005c7aa5f15 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -3680,8 +3680,8 @@ module ts {
             }
 
             function emitModuleDeclaration(node: ModuleDeclaration) {
-                var shouldEmit = getModuleInstanceState(node) === ModuleInstanceState.Instantiated ||
-                    (getModuleInstanceState(node) === ModuleInstanceState.ConstEnumOnly && compilerOptions.preserveConstEnums);
+                // Emit only if this module is non-ambient.
+                var shouldEmit = isInstantiatedModule(node, compilerOptions.preserveConstEnums);
 
                 if (!shouldEmit) {
                     return emitPinnedOrTripleSlashComments(node);
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index bbe4d7dbf35..114e1dae1b3 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -525,6 +525,12 @@ module ts {
         return false;
     }
 
+    export function isInstantiatedModule(node: ModuleDeclaration, preserveConstEnums: boolean) {
+        var moduleState = getModuleInstanceState(node)
+        return moduleState === ModuleInstanceState.Instantiated ||
+               (preserveConstEnums && moduleState === ModuleInstanceState.ConstEnumOnly);
+    }
+
     export function isExternalModuleImportDeclaration(node: Node) {
         return node.kind === SyntaxKind.ImportDeclaration && (<ImportDeclaration>node).moduleReference.kind === SyntaxKind.ExternalModuleReference;
     }
diff --git a/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.errors.txt b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.errors.txt
deleted file mode 100644
index cae69212f2f..00000000000
--- a/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.errors.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts(2,8): error TS2434: A module declaration cannot be located prior to a class or function with which it is merged
-
-
-==== tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts (1 errors) ====
-    // Ambient/uninstantiated module.
-    module Moclodule {
-           ~~~~~~~~~
-!!! error TS2434: A module declaration cannot be located prior to a class or function with which it is merged
-        export interface Someinterface {
-            foo(): void;
-        }
-    }
-    
-    class Moclodule {
-    }
-    
-    // Instantiated module.
-    module Moclodule {
-        export class Manager {
-        }
-    }
\ No newline at end of file
diff --git a/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.types b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.types
new file mode 100644
index 00000000000..1ab286b5964
--- /dev/null
+++ b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.types
@@ -0,0 +1,25 @@
+=== tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts ===
+// Ambient/uninstantiated module.
+module Moclodule {
+>Moclodule : typeof Moclodule
+
+    export interface Someinterface {
+>Someinterface : Someinterface
+
+        foo(): void;
+>foo : () => void
+    }
+}
+
+class Moclodule {
+>Moclodule : Moclodule
+}
+
+// Instantiated module.
+module Moclodule {
+>Moclodule : typeof Moclodule
+
+    export class Manager {
+>Manager : Manager
+    }
+}

From 46cd90daf080b2f8e3bd88cb7eda4193e4a05fc9 Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <drosen@microsoft.com>
Date: Wed, 17 Dec 2014 17:05:05 -0800
Subject: [PATCH 03/11] Added test, modified test, updated baselines.

---
 ...duleWithPriorInstantiatedModule.errors.txt | 22 +++++++++++
 .../cloduleWithPriorInstantiatedModule.js     | 39 +++++++++++++++++++
 .../cloduleWithPriorUninstantiatedModule.js   |  2 +-
 ...cloduleWithPriorUninstantiatedModule.types |  2 +-
 .../cloduleWithPriorInstantiatedModule.ts     | 16 ++++++++
 .../cloduleWithPriorUninstantiatedModule.ts   |  2 +-
 6 files changed, 80 insertions(+), 3 deletions(-)
 create mode 100644 tests/baselines/reference/cloduleWithPriorInstantiatedModule.errors.txt
 create mode 100644 tests/baselines/reference/cloduleWithPriorInstantiatedModule.js
 create mode 100644 tests/cases/compiler/cloduleWithPriorInstantiatedModule.ts

diff --git a/tests/baselines/reference/cloduleWithPriorInstantiatedModule.errors.txt b/tests/baselines/reference/cloduleWithPriorInstantiatedModule.errors.txt
new file mode 100644
index 00000000000..1b0d9cf13ca
--- /dev/null
+++ b/tests/baselines/reference/cloduleWithPriorInstantiatedModule.errors.txt
@@ -0,0 +1,22 @@
+tests/cases/compiler/cloduleWithPriorInstantiatedModule.ts(2,8): error TS2434: A module declaration cannot be located prior to a class or function with which it is merged
+
+
+==== tests/cases/compiler/cloduleWithPriorInstantiatedModule.ts (1 errors) ====
+    // Non-ambient & instantiated module.
+    module Moclodule {
+           ~~~~~~~~~
+!!! error TS2434: A module declaration cannot be located prior to a class or function with which it is merged
+        export interface Someinterface {
+            foo(): void;
+        }
+        var x = 10;
+    }
+    
+    class Moclodule {
+    }
+    
+    // Instantiated module.
+    module Moclodule {
+        export class Manager {
+        }
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/cloduleWithPriorInstantiatedModule.js b/tests/baselines/reference/cloduleWithPriorInstantiatedModule.js
new file mode 100644
index 00000000000..601ab0a7536
--- /dev/null
+++ b/tests/baselines/reference/cloduleWithPriorInstantiatedModule.js
@@ -0,0 +1,39 @@
+//// [cloduleWithPriorInstantiatedModule.ts]
+// Non-ambient & instantiated module.
+module Moclodule {
+    export interface Someinterface {
+        foo(): void;
+    }
+    var x = 10;
+}
+
+class Moclodule {
+}
+
+// Instantiated module.
+module Moclodule {
+    export class Manager {
+    }
+}
+
+//// [cloduleWithPriorInstantiatedModule.js]
+// Non-ambient & instantiated module.
+var Moclodule;
+(function (Moclodule) {
+    var x = 10;
+})(Moclodule || (Moclodule = {}));
+var Moclodule = (function () {
+    function Moclodule() {
+    }
+    return Moclodule;
+})();
+// Instantiated module.
+var Moclodule;
+(function (Moclodule) {
+    var Manager = (function () {
+        function Manager() {
+        }
+        return Manager;
+    })();
+    Moclodule.Manager = Manager;
+})(Moclodule || (Moclodule = {}));
diff --git a/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.js b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.js
index 37bfb617375..cf06f1134fb 100644
--- a/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.js
+++ b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.js
@@ -1,5 +1,5 @@
 //// [cloduleWithPriorUninstantiatedModule.ts]
-// Ambient/uninstantiated module.
+// Non-ambient & uninstantiated module.
 module Moclodule {
     export interface Someinterface {
         foo(): void;
diff --git a/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.types b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.types
index 1ab286b5964..8dc14646a6b 100644
--- a/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.types
+++ b/tests/baselines/reference/cloduleWithPriorUninstantiatedModule.types
@@ -1,5 +1,5 @@
 === tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts ===
-// Ambient/uninstantiated module.
+// Non-ambient & uninstantiated module.
 module Moclodule {
 >Moclodule : typeof Moclodule
 
diff --git a/tests/cases/compiler/cloduleWithPriorInstantiatedModule.ts b/tests/cases/compiler/cloduleWithPriorInstantiatedModule.ts
new file mode 100644
index 00000000000..c6423ce41a7
--- /dev/null
+++ b/tests/cases/compiler/cloduleWithPriorInstantiatedModule.ts
@@ -0,0 +1,16 @@
+// Non-ambient & instantiated module.
+module Moclodule {
+    export interface Someinterface {
+        foo(): void;
+    }
+    var x = 10;
+}
+
+class Moclodule {
+}
+
+// Instantiated module.
+module Moclodule {
+    export class Manager {
+    }
+}
\ No newline at end of file
diff --git a/tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts b/tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts
index 8c9c646b687..0c603b71a4d 100644
--- a/tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts
+++ b/tests/cases/compiler/cloduleWithPriorUninstantiatedModule.ts
@@ -1,4 +1,4 @@
-// Ambient/uninstantiated module.
+// Non-ambient & uninstantiated module.
 module Moclodule {
     export interface Someinterface {
         foo(): void;

From d907f99693aac97f714fef0c72af433326ad681a Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <drosen@microsoft.com>
Date: Mon, 22 Dec 2014 13:58:14 -0800
Subject: [PATCH 04/11] Moved EmitHost to types.ts so that utilities can be
 edited as a standalone file through dependency resolution.

---
 src/compiler/emitter.ts | 13 +------------
 src/compiler/types.ts   | 12 ++++++++++++
 2 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 237f3ab509a..1065a1e0e60 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -1461,18 +1461,7 @@ module ts {
             referencePathsOutput,
         }
     }
-
-    export interface EmitHost extends ScriptReferenceHost {
-        getSourceFiles(): SourceFile[];
-        isEmitBlocked(sourceFile?: SourceFile): boolean;
-
-        getCommonSourceDirectory(): string;
-        getCanonicalFileName(fileName: string): string;
-        getNewLine(): string;
-
-        writeFile(filename: string, data: string, writeByteOrderMark: boolean, onError?: (message: string) => void): void;
-    }
-
+    
     export function getDeclarationDiagnostics(host: EmitHost, resolver: EmitResolver, targetSourceFile: SourceFile): Diagnostic[] {
         var diagnostics: Diagnostic[] = [];
         var jsFilePath = getOwnEmitOutputFilePath(targetSourceFile, host, ".js");
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index cc1b37aef5d..f95200c4cb3 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -951,6 +951,18 @@ module ts {
         isEmitBlocked(sourceFile?: SourceFile): boolean;
     }
 
+    export interface EmitHost extends ScriptReferenceHost {
+        getSourceFiles(): SourceFile[];
+        isEmitBlocked(sourceFile?: SourceFile): boolean;
+
+        getCommonSourceDirectory(): string;
+        getCanonicalFileName(fileName: string): string;
+        getNewLine(): string;
+
+        writeFile(filename: string, data: string, writeByteOrderMark: boolean, onError?: (message: string) => void): void;
+    }
+
+
     export interface SourceMapSpan {
         emittedLine: number;    // Line number in the .js file
         emittedColumn: number;  // Column number in the .js file

From 8aefbe9a86999654a0b4858ecf6db9a13cd37ac0 Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <drosen@microsoft.com>
Date: Mon, 22 Dec 2014 14:02:40 -0800
Subject: [PATCH 05/11] Removed newline.

---
 src/compiler/types.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index f95200c4cb3..dbdd71ed363 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -962,7 +962,6 @@ module ts {
         writeFile(filename: string, data: string, writeByteOrderMark: boolean, onError?: (message: string) => void): void;
     }
 
-
     export interface SourceMapSpan {
         emittedLine: number;    // Line number in the .js file
         emittedColumn: number;  // Column number in the .js file

From 363587163b4e83d6e6abdf92ce3f96653fca1e65 Mon Sep 17 00:00:00 2001
From: Vladimir Matveev <vladima@microsoft.com>
Date: Fri, 2 Jan 2015 12:14:02 -0800
Subject: [PATCH 06/11] extract map copying logic to a separate function

---
 src/compiler/checker.ts | 4 +---
 src/compiler/core.ts    | 6 ++++++
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index f8c4caa9630..351f5188748 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -3651,9 +3651,7 @@ module ts {
                     var maybeCache = maybeStack[depth];
                     // If result is definitely true, copy assumptions to global cache, else copy to next level up
                     var destinationCache = result === Ternary.True || depth === 0 ? relation : maybeStack[depth - 1];
-                    for (var p in maybeCache) {
-                        destinationCache[p] = maybeCache[p];
-                    }
+                    copyMap(maybeCache, destinationCache);
                 }
                 else {
                     // A false result goes straight into global cache (when something is false under assumptions it
diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index 4ba93729c36..2e5a471bb27 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -208,6 +208,12 @@ module ts {
         return result;
     }
 
+    export function copyMap<T>(source: Map<T>, target: Map<T>): void {
+        for (var p in source) {
+            target[p] = source[p];
+        }
+    }
+
     /**
      * Creates a map from the elements of an array.
      *

From 06258b8c106385924077c4a17d908114612dea0b Mon Sep 17 00:00:00 2001
From: Vladimir Matveev <vladima@microsoft.com>
Date: Mon, 5 Jan 2015 11:48:46 -0800
Subject: [PATCH 07/11] added parameter names to 'copymap' call site

---
 src/compiler/checker.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 351f5188748..2911322052d 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -3651,7 +3651,7 @@ module ts {
                     var maybeCache = maybeStack[depth];
                     // If result is definitely true, copy assumptions to global cache, else copy to next level up
                     var destinationCache = result === Ternary.True || depth === 0 ? relation : maybeStack[depth - 1];
-                    copyMap(maybeCache, destinationCache);
+                    copyMap(/*source*/maybeCache, /*target*/destinationCache);
                 }
                 else {
                     // A false result goes straight into global cache (when something is false under assumptions it

From b442d14e440cd3db7a797016e9b11de2b3f12cb3 Mon Sep 17 00:00:00 2001
From: Arnavion <arnavion@gmail.com>
Date: Tue, 6 Jan 2015 15:28:06 -0800
Subject: [PATCH 08/11] Don't emit an empty template head literal if there's a
 template span with a non-empty literal.

Fixes #1570
---
 src/compiler/emitter.ts | 43 +++++++++++++++++++++++++++++++++++++----
 1 file changed, 39 insertions(+), 4 deletions(-)

diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index f3e45a85b6a..ba32e46065e 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -2068,9 +2068,15 @@ module ts {
                     write("(");
                 }
 
-                emitLiteral(node.head);
+                var headEmitted = false;
+                if (shouldEmitTemplateHead()) {
+                    emitLiteral(node.head);
+                    headEmitted = true;
+                }
+
+                for (var i = 0; i < node.templateSpans.length; i++) {
+                    var templateSpan = node.templateSpans[i];
 
-                forEach(node.templateSpans, templateSpan => {
                     // Check if the expression has operands and binds its operands less closely than binary '+'.
                     // If it does, we need to wrap the expression in parentheses. Otherwise, something like
                     //    `abc${ 1 << 2 }`
@@ -2082,7 +2088,14 @@ module ts {
                     //    "abc" + (1 << 2) + ""
                     var needsParens = templateSpan.expression.kind !== SyntaxKind.ParenthesizedExpression
                         && comparePrecedenceToBinaryPlus(templateSpan.expression) !== Comparison.GreaterThan;
-                    write(" + ");
+
+                    if (i > 0 || headEmitted) {
+                        // If this is the first span and the head was not emitted, then this templateSpan's
+                        // expression will be the first to be emitted. Don't emit the preceding ' + ' in that
+                        // case.
+                        write(" + ");
+                    }
+
                     emitParenthesized(templateSpan.expression, needsParens);
                     // Only emit if the literal is non-empty.
                     // The binary '+' operator is left-associative, so the first string concatenation
@@ -2092,12 +2105,34 @@ module ts {
                         write(" + ")
                         emitLiteral(templateSpan.literal);
                     }
-                });
+                }
 
                 if (emitOuterParens) {
                     write(")");
                 }
 
+                function shouldEmitTemplateHead() {
+                    // If this expression has an empty head literal and the first template span has a non-empty
+                    // literal, then emitting the empty head literal is not necessary.
+                    //     `${ foo } and ${ bar }`
+                    // can be emitted as
+                    //     foo + " and " + bar
+                    // This is because it is only required that one of the first two operands in the emit
+                    // output must be a string literal, so that the other operand and all following operands
+                    // are forced into strings.
+                    //
+                    // If the first template span has an empty literal, then the head must still be emitted.
+                    //     `${ foo }${ bar }`
+                    // must still be emitted as
+                    //     "" + foo + bar
+
+                    // There is always atleast one templateSpan in this code path, since
+                    // NoSubstitutionTemplateLiterals are directly emitted via emitLiteral()
+                    Debug.assert(node.templateSpans.length !== 0);
+
+                    return node.head.text.length !== 0 || node.templateSpans[0].literal.text.length === 0;
+                }
+
                 function templateNeedsParens(template: TemplateExpression, parent: Expression) {
                     switch (parent.kind) {
                         case SyntaxKind.CallExpression:

From d07151f87c81247a45d3844c8b079d9c30472884 Mon Sep 17 00:00:00 2001
From: Arnavion <arnavion@gmail.com>
Date: Tue, 6 Jan 2015 15:28:06 -0800
Subject: [PATCH 09/11] Update tests and baselines.

---
 .../templateStringBinaryOperations.js         | 24 +++++-----
 .../templateStringBinaryOperationsInvalid.js  | 48 +++++++++----------
 .../templateStringWithEmptyLiteralPortions.js | 12 +++--
 ...mplateStringWithEmptyLiteralPortions.types |  5 +-
 ...mplateStringWithEmptyLiteralPortionsES6.js |  8 +++-
 ...ateStringWithEmptyLiteralPortionsES6.types |  5 +-
 .../templateStringWithEmptyLiteralPortions.ts |  4 +-
 ...mplateStringWithEmptyLiteralPortionsES6.ts |  4 +-
 8 files changed, 64 insertions(+), 46 deletions(-)

diff --git a/tests/baselines/reference/templateStringBinaryOperations.js b/tests/baselines/reference/templateStringBinaryOperations.js
index d155ba9eedd..691dad41f77 100644
--- a/tests/baselines/reference/templateStringBinaryOperations.js
+++ b/tests/baselines/reference/templateStringBinaryOperations.js
@@ -55,49 +55,49 @@ var l4 = 1 + `2${ 3 & 4 }5` + 6;
 //// [templateStringBinaryOperations.js]
 var a = 1 + ("" + 3);
 var b = 1 + ("2" + 3);
-var c = 1 + ("" + 3 + "4");
+var c = 1 + (3 + "4");
 var d = 1 + ("2" + 3 + "4");
 var e = ("" + 3) + 5;
 var f = ("2" + 3) + 5;
-var g = ("" + 3 + "4") + 5;
+var g = (3 + "4") + 5;
 var h = ("2" + 3 + "4") + 5;
 var i = 1 + ("" + 3) + 5;
 var j = 1 + ("2" + 3) + 5;
-var k = 1 + ("" + 3 + "4") + 5;
+var k = 1 + (3 + "4") + 5;
 var l = 1 + ("2" + 3 + "4") + 5;
 var a2 = 1 + ("" + (3 - 4));
 var b2 = 1 + ("2" + (3 - 4));
-var c2 = 1 + ("" + (3 - 4) + "5");
+var c2 = 1 + ((3 - 4) + "5");
 var d2 = 1 + ("2" + (3 - 4) + "5");
 var e2 = ("" + (3 - 4)) + 6;
 var f2 = ("2" + (3 - 4)) + 6;
-var g2 = ("" + (3 - 4) + "5") + 6;
+var g2 = ((3 - 4) + "5") + 6;
 var h2 = ("2" + (3 - 4) + "5") + 6;
 var i2 = 1 + ("" + (3 - 4)) + 6;
 var j2 = 1 + ("2" + (3 - 4)) + 6;
-var k2 = 1 + ("" + (3 - 4) + "5") + 6;
+var k2 = 1 + ((3 - 4) + "5") + 6;
 var l2 = 1 + ("2" + (3 - 4) + "5") + 6;
 var a3 = 1 + ("" + 3 * 4);
 var b3 = 1 + ("2" + 3 * 4);
-var c3 = 1 + ("" + 3 * 4 + "5");
+var c3 = 1 + (3 * 4 + "5");
 var d3 = 1 + ("2" + 3 * 4 + "5");
 var e3 = ("" + 3 * 4) + 6;
 var f3 = ("2" + 3 * 4) + 6;
-var g3 = ("" + 3 * 4 + "5") + 6;
+var g3 = (3 * 4 + "5") + 6;
 var h3 = ("2" + 3 * 4 + "5") + 6;
 var i3 = 1 + ("" + 3 * 4) + 6;
 var j3 = 1 + ("2" + 3 * 4) + 6;
-var k3 = 1 + ("" + 3 * 4 + "5") + 6;
+var k3 = 1 + (3 * 4 + "5") + 6;
 var l3 = 1 + ("2" + 3 * 4 + "5") + 6;
 var a4 = 1 + ("" + (3 & 4));
 var b4 = 1 + ("2" + (3 & 4));
-var c4 = 1 + ("" + (3 & 4) + "5");
+var c4 = 1 + ((3 & 4) + "5");
 var d4 = 1 + ("2" + (3 & 4) + "5");
 var e4 = ("" + (3 & 4)) + 6;
 var f4 = ("2" + (3 & 4)) + 6;
-var g4 = ("" + (3 & 4) + "5") + 6;
+var g4 = ((3 & 4) + "5") + 6;
 var h4 = ("2" + (3 & 4) + "5") + 6;
 var i4 = 1 + ("" + (3 & 4)) + 6;
 var j4 = 1 + ("2" + (3 & 4)) + 6;
-var k4 = 1 + ("" + (3 & 4) + "5") + 6;
+var k4 = 1 + ((3 & 4) + "5") + 6;
 var l4 = 1 + ("2" + (3 & 4) + "5") + 6;
diff --git a/tests/baselines/reference/templateStringBinaryOperationsInvalid.js b/tests/baselines/reference/templateStringBinaryOperationsInvalid.js
index 1edf1d3a563..f8c0344f44b 100644
--- a/tests/baselines/reference/templateStringBinaryOperationsInvalid.js
+++ b/tests/baselines/reference/templateStringBinaryOperationsInvalid.js
@@ -111,97 +111,97 @@ var hc = `2${ 3 & 4 }5` & 6;
 //// [templateStringBinaryOperationsInvalid.js]
 var a = 1 - ("" + 3);
 var b = 1 - ("2" + 3);
-var c = 1 - ("" + 3 + "4");
+var c = 1 - (3 + "4");
 var d = 1 - ("2" + 3 + "4");
 var e = ("" + 3) - 5;
 var f = ("2" + 3) - 5;
-var g = ("" + 3 + "4") - 5;
+var g = (3 + "4") - 5;
 var h = ("2" + 3 + "4") - 5;
 var a2 = 1 * ("" + 3);
 var b2 = 1 * ("2" + 3);
-var c2 = 1 * ("" + 3 + "4");
+var c2 = 1 * (3 + "4");
 var d2 = 1 * ("2" + 3 + "4");
 var e2 = ("" + 3) * 5;
 var f2 = ("2" + 3) * 5;
-var g2 = ("" + 3 + "4") * 5;
+var g2 = (3 + "4") * 5;
 var h2 = ("2" + 3 + "4") * 5;
 var a3 = 1 & "" + 3;
 var b3 = 1 & "2" + 3;
-var c3 = 1 & "" + 3 + "4";
+var c3 = 1 & 3 + "4";
 var d3 = 1 & "2" + 3 + "4";
 var e3 = "" + 3 & 5;
 var f3 = "2" + 3 & 5;
-var g3 = "" + 3 + "4" & 5;
+var g3 = 3 + "4" & 5;
 var h3 = "2" + 3 + "4" & 5;
 var a4 = 1 - ("" + (3 - 4));
 var b4 = 1 - ("2" + (3 - 4));
-var c4 = 1 - ("" + (3 - 4) + "5");
+var c4 = 1 - ((3 - 4) + "5");
 var d4 = 1 - ("2" + (3 - 4) + "5");
 var e4 = ("" + (3 - 4)) - 6;
 var f4 = ("2" + (3 - 4)) - 6;
-var g4 = ("" + (3 - 4) + "5") - 6;
+var g4 = ((3 - 4) + "5") - 6;
 var h4 = ("2" + (3 - 4) + "5") - 6;
 var a5 = 1 - ("" + 3 * 4);
 var b5 = 1 - ("2" + 3 * 4);
-var c5 = 1 - ("" + 3 * 4 + "5");
+var c5 = 1 - (3 * 4 + "5");
 var d5 = 1 - ("2" + 3 * 4 + "5");
 var e5 = ("" + 3 * 4) - 6;
 var f5 = ("2" + 3 * 4) - 6;
-var g5 = ("" + 3 * 4 + "5") - 6;
+var g5 = (3 * 4 + "5") - 6;
 var h5 = ("2" + 3 * 4 + "5") - 6;
 var a6 = 1 - ("" + (3 & 4));
 var b6 = 1 - ("2" + (3 & 4));
-var c6 = 1 - ("" + (3 & 4) + "5");
+var c6 = 1 - ((3 & 4) + "5");
 var d6 = 1 - ("2" + (3 & 4) + "5");
 var e6 = ("" + (3 & 4)) - 6;
 var f6 = ("2" + (3 & 4)) - 6;
-var g6 = ("" + (3 & 4) + "5") - 6;
+var g6 = ((3 & 4) + "5") - 6;
 var h6 = ("2" + (3 & 4) + "5") - 6;
 var a7 = 1 * ("" + (3 - 4));
 var b7 = 1 * ("2" + (3 - 4));
-var c7 = 1 * ("" + (3 - 4) + "5");
+var c7 = 1 * ((3 - 4) + "5");
 var d7 = 1 * ("2" + (3 - 4) + "5");
 var e7 = ("" + (3 - 4)) * 6;
 var f7 = ("2" + (3 - 4)) * 6;
-var g7 = ("" + (3 - 4) + "5") * 6;
+var g7 = ((3 - 4) + "5") * 6;
 var h7 = ("2" + (3 - 4) + "5") * 6;
 var a8 = 1 * ("" + 3 * 4);
 var b8 = 1 * ("2" + 3 * 4);
-var c8 = 1 * ("" + 3 * 4 + "5");
+var c8 = 1 * (3 * 4 + "5");
 var d8 = 1 * ("2" + 3 * 4 + "5");
 var e8 = ("" + 3 * 4) * 6;
 var f8 = ("2" + 3 * 4) * 6;
-var g8 = ("" + 3 * 4 + "5") * 6;
+var g8 = (3 * 4 + "5") * 6;
 var h8 = ("2" + 3 * 4 + "5") * 6;
 var a9 = 1 * ("" + (3 & 4));
 var b9 = 1 * ("2" + (3 & 4));
-var c9 = 1 * ("" + (3 & 4) + "5");
+var c9 = 1 * ((3 & 4) + "5");
 var d9 = 1 * ("2" + (3 & 4) + "5");
 var e9 = ("" + (3 & 4)) * 6;
 var f9 = ("2" + (3 & 4)) * 6;
-var g9 = ("" + (3 & 4) + "5") * 6;
+var g9 = ((3 & 4) + "5") * 6;
 var h9 = ("2" + (3 & 4) + "5") * 6;
 var aa = 1 & "" + (3 - 4);
 var ba = 1 & "2" + (3 - 4);
-var ca = 1 & "" + (3 - 4) + "5";
+var ca = 1 & (3 - 4) + "5";
 var da = 1 & "2" + (3 - 4) + "5";
 var ea = "" + (3 - 4) & 6;
 var fa = "2" + (3 - 4) & 6;
-var ga = "" + (3 - 4) + "5" & 6;
+var ga = (3 - 4) + "5" & 6;
 var ha = "2" + (3 - 4) + "5" & 6;
 var ab = 1 & "" + 3 * 4;
 var bb = 1 & "2" + 3 * 4;
-var cb = 1 & "" + 3 * 4 + "5";
+var cb = 1 & 3 * 4 + "5";
 var db = 1 & "2" + 3 * 4 + "5";
 var eb = "" + 3 * 4 & 6;
 var fb = "2" + 3 * 4 & 6;
-var gb = "" + 3 * 4 + "5" & 6;
+var gb = 3 * 4 + "5" & 6;
 var hb = "2" + 3 * 4 + "5" & 6;
 var ac = 1 & "" + (3 & 4);
 var bc = 1 & "2" + (3 & 4);
-var cc = 1 & "" + (3 & 4) + "5";
+var cc = 1 & (3 & 4) + "5";
 var dc = 1 & "2" + (3 & 4) + "5";
 var ec = "" + (3 & 4) & 6;
 var fc = "2" + (3 & 4) & 6;
-var gc = "" + (3 & 4) + "5" & 6;
+var gc = (3 & 4) + "5" & 6;
 var hc = "2" + (3 & 4) + "5" & 6;
diff --git a/tests/baselines/reference/templateStringWithEmptyLiteralPortions.js b/tests/baselines/reference/templateStringWithEmptyLiteralPortions.js
index 8bc6e2c4206..e7a35d76f45 100644
--- a/tests/baselines/reference/templateStringWithEmptyLiteralPortions.js
+++ b/tests/baselines/reference/templateStringWithEmptyLiteralPortions.js
@@ -21,18 +21,22 @@ var j = `${ 0 }${ 0 }3`;
 
 var k = `1${ 0 }${ 0 }3`;
 
-var l = `1${ 0 }2${ 0 }3`;
+var l = `${ 0 }2${ 0 }3`;
+
+var m = `1${ 0 }2${ 0 }3`;
+
 
 //// [templateStringWithEmptyLiteralPortions.js]
 var a = "";
 var b = "" + 0;
 var c = "1" + 0;
-var d = "" + 0 + "2";
+var d = 0 + "2";
 var e = "1" + 0 + "2";
 var f = "" + 0 + 0;
 var g = "1" + 0 + 0;
-var h = "" + 0 + "2" + 0;
+var h = 0 + "2" + 0;
 var i = "1" + 0 + "2" + 0;
 var j = "" + 0 + 0 + "3";
 var k = "1" + 0 + 0 + "3";
-var l = "1" + 0 + "2" + 0 + "3";
+var l = 0 + "2" + 0 + "3";
+var m = "1" + 0 + "2" + 0 + "3";
diff --git a/tests/baselines/reference/templateStringWithEmptyLiteralPortions.types b/tests/baselines/reference/templateStringWithEmptyLiteralPortions.types
index a44bab8fe44..c901d674306 100644
--- a/tests/baselines/reference/templateStringWithEmptyLiteralPortions.types
+++ b/tests/baselines/reference/templateStringWithEmptyLiteralPortions.types
@@ -32,6 +32,9 @@ var j = `${ 0 }${ 0 }3`;
 var k = `1${ 0 }${ 0 }3`;
 >k : string
 
-var l = `1${ 0 }2${ 0 }3`;
+var l = `${ 0 }2${ 0 }3`;
 >l : string
 
+var m = `1${ 0 }2${ 0 }3`;
+>m : string
+
diff --git a/tests/baselines/reference/templateStringWithEmptyLiteralPortionsES6.js b/tests/baselines/reference/templateStringWithEmptyLiteralPortionsES6.js
index f0e827cde63..fe1bce291f0 100644
--- a/tests/baselines/reference/templateStringWithEmptyLiteralPortionsES6.js
+++ b/tests/baselines/reference/templateStringWithEmptyLiteralPortionsES6.js
@@ -21,7 +21,10 @@ var j = `${ 0 }${ 0 }3`;
 
 var k = `1${ 0 }${ 0 }3`;
 
-var l = `1${ 0 }2${ 0 }3`;
+var l = `${ 0 }2${ 0 }3`;
+
+var m = `1${ 0 }2${ 0 }3`;
+
 
 //// [templateStringWithEmptyLiteralPortionsES6.js]
 var a = ``;
@@ -35,4 +38,5 @@ var h = `${0}2${0}`;
 var i = `1${0}2${0}`;
 var j = `${0}${0}3`;
 var k = `1${0}${0}3`;
-var l = `1${0}2${0}3`;
+var l = `${0}2${0}3`;
+var m = `1${0}2${0}3`;
diff --git a/tests/baselines/reference/templateStringWithEmptyLiteralPortionsES6.types b/tests/baselines/reference/templateStringWithEmptyLiteralPortionsES6.types
index 4074831d410..d70dd29e4da 100644
--- a/tests/baselines/reference/templateStringWithEmptyLiteralPortionsES6.types
+++ b/tests/baselines/reference/templateStringWithEmptyLiteralPortionsES6.types
@@ -32,6 +32,9 @@ var j = `${ 0 }${ 0 }3`;
 var k = `1${ 0 }${ 0 }3`;
 >k : string
 
-var l = `1${ 0 }2${ 0 }3`;
+var l = `${ 0 }2${ 0 }3`;
 >l : string
 
+var m = `1${ 0 }2${ 0 }3`;
+>m : string
+
diff --git a/tests/cases/conformance/es6/templates/templateStringWithEmptyLiteralPortions.ts b/tests/cases/conformance/es6/templates/templateStringWithEmptyLiteralPortions.ts
index 11dca4caf77..9191ca1934c 100644
--- a/tests/cases/conformance/es6/templates/templateStringWithEmptyLiteralPortions.ts
+++ b/tests/cases/conformance/es6/templates/templateStringWithEmptyLiteralPortions.ts
@@ -20,4 +20,6 @@ var j = `${ 0 }${ 0 }3`;
 
 var k = `1${ 0 }${ 0 }3`;
 
-var l = `1${ 0 }2${ 0 }3`;
\ No newline at end of file
+var l = `${ 0 }2${ 0 }3`;
+
+var m = `1${ 0 }2${ 0 }3`;
diff --git a/tests/cases/conformance/es6/templates/templateStringWithEmptyLiteralPortionsES6.ts b/tests/cases/conformance/es6/templates/templateStringWithEmptyLiteralPortionsES6.ts
index 183da57dd45..ff178d22432 100644
--- a/tests/cases/conformance/es6/templates/templateStringWithEmptyLiteralPortionsES6.ts
+++ b/tests/cases/conformance/es6/templates/templateStringWithEmptyLiteralPortionsES6.ts
@@ -21,4 +21,6 @@ var j = `${ 0 }${ 0 }3`;
 
 var k = `1${ 0 }${ 0 }3`;
 
-var l = `1${ 0 }2${ 0 }3`;
\ No newline at end of file
+var l = `${ 0 }2${ 0 }3`;
+
+var m = `1${ 0 }2${ 0 }3`;

From 01218f86ffe2ed6002016a1f3bf3b91bb118830f Mon Sep 17 00:00:00 2001
From: Vladimir Matveev <vladima@microsoft.com>
Date: Tue, 6 Jan 2015 17:55:54 -0800
Subject: [PATCH 10/11] consider type parameters always visible

---
 src/compiler/checker.ts                       |  5 ++--
 .../reference/visibilityOfTypeParameters.js   | 24 +++++++++++++++++++
 .../visibilityOfTypeParameters.types          | 16 +++++++++++++
 .../compiler/visibilityOfTypeParameters.ts    |  8 +++++++
 4 files changed, 51 insertions(+), 2 deletions(-)
 create mode 100644 tests/baselines/reference/visibilityOfTypeParameters.js
 create mode 100644 tests/baselines/reference/visibilityOfTypeParameters.types
 create mode 100644 tests/cases/compiler/visibilityOfTypeParameters.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index e07c0eb237e..9849e740e9d 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -1575,7 +1575,6 @@ module ts {
                     case SyntaxKind.IndexSignature:
                     case SyntaxKind.Parameter:
                     case SyntaxKind.ModuleBlock:
-                    case SyntaxKind.TypeParameter:
                     case SyntaxKind.FunctionType:
                     case SyntaxKind.ConstructorType:
                     case SyntaxKind.TypeLiteral:
@@ -1585,7 +1584,9 @@ module ts {
                     case SyntaxKind.UnionType:
                     case SyntaxKind.ParenthesizedType:
                         return isDeclarationVisible(<Declaration>node.parent);
-
+                    
+                    // Type parameters are always visible
+                    case SyntaxKind.TypeParameter:
                     // Source file is always visible
                     case SyntaxKind.SourceFile:
                         return true;
diff --git a/tests/baselines/reference/visibilityOfTypeParameters.js b/tests/baselines/reference/visibilityOfTypeParameters.js
new file mode 100644
index 00000000000..2cb006737b2
--- /dev/null
+++ b/tests/baselines/reference/visibilityOfTypeParameters.js
@@ -0,0 +1,24 @@
+//// [visibilityOfTypeParameters.ts]
+
+export class MyClass {
+    protected myMethod<T>(val: T): T {
+        return val;
+    }
+}
+
+//// [visibilityOfTypeParameters.js]
+var MyClass = (function () {
+    function MyClass() {
+    }
+    MyClass.prototype.myMethod = function (val) {
+        return val;
+    };
+    return MyClass;
+})();
+exports.MyClass = MyClass;
+
+
+//// [visibilityOfTypeParameters.d.ts]
+export declare class MyClass {
+    protected myMethod<T>(val: T): T;
+}
diff --git a/tests/baselines/reference/visibilityOfTypeParameters.types b/tests/baselines/reference/visibilityOfTypeParameters.types
new file mode 100644
index 00000000000..60a9330eb7e
--- /dev/null
+++ b/tests/baselines/reference/visibilityOfTypeParameters.types
@@ -0,0 +1,16 @@
+=== tests/cases/compiler/visibilityOfTypeParameters.ts ===
+
+export class MyClass {
+>MyClass : MyClass
+
+    protected myMethod<T>(val: T): T {
+>myMethod : <T>(val: T) => T
+>T : T
+>val : T
+>T : T
+>T : T
+
+        return val;
+>val : T
+    }
+}
diff --git a/tests/cases/compiler/visibilityOfTypeParameters.ts b/tests/cases/compiler/visibilityOfTypeParameters.ts
new file mode 100644
index 00000000000..386d0bb9cb4
--- /dev/null
+++ b/tests/cases/compiler/visibilityOfTypeParameters.ts
@@ -0,0 +1,8 @@
+// @module:commonjs
+//@declaration: true
+
+export class MyClass {
+    protected myMethod<T>(val: T): T {
+        return val;
+    }
+}
\ No newline at end of file

From 06d65c797d91816d4c7b5bfe4f25ee1c01dd9691 Mon Sep 17 00:00:00 2001
From: Daniel Rosenwasser <drosen@microsoft.com>
Date: Wed, 7 Jan 2015 12:37:46 -0800
Subject: [PATCH 11/11] Moved EmitHost to utilities.ts

---
 src/compiler/types.ts     | 11 -----------
 src/compiler/utilities.ts | 11 +++++++++++
 2 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index dbdd71ed363..cc1b37aef5d 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -951,17 +951,6 @@ module ts {
         isEmitBlocked(sourceFile?: SourceFile): boolean;
     }
 
-    export interface EmitHost extends ScriptReferenceHost {
-        getSourceFiles(): SourceFile[];
-        isEmitBlocked(sourceFile?: SourceFile): boolean;
-
-        getCommonSourceDirectory(): string;
-        getCanonicalFileName(fileName: string): string;
-        getNewLine(): string;
-
-        writeFile(filename: string, data: string, writeByteOrderMark: boolean, onError?: (message: string) => void): void;
-    }
-
     export interface SourceMapSpan {
         emittedLine: number;    // Line number in the .js file
         emittedColumn: number;  // Column number in the .js file
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index edd8bf156cf..9686622decb 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -23,6 +23,17 @@ module ts {
         string(): string;
     }
 
+    export interface EmitHost extends ScriptReferenceHost {
+        getSourceFiles(): SourceFile[];
+        isEmitBlocked(sourceFile?: SourceFile): boolean;
+
+        getCommonSourceDirectory(): string;
+        getCanonicalFileName(fileName: string): string;
+        getNewLine(): string;
+
+        writeFile(filename: string, data: string, writeByteOrderMark: boolean, onError?: (message: string) => void): void;
+    }
+
     // Pool writers to avoid needing to allocate them for every symbol we write.
     var stringWriters: StringSymbolWriter[] = [];
     export function getSingleLineStringWriter(): StringSymbolWriter {