Support modules when targeting ES6 and an ES6 ModuleKind

src/compiler/commandLineParser.ts

@@ -76,10 +76,11 @@ namespace ts {
                 "amd": ModuleKind.AMD,
                 "system": ModuleKind.System,
                 "umd": ModuleKind.UMD,
+                "es6": ModuleKind.ES6,
             },
-            description: Diagnostics.Specify_module_code_generation_Colon_commonjs_amd_system_or_umd,
+            description: Diagnostics.Specify_module_code_generation_Colon_commonjs_amd_system_umd_or_es6,
             paramType: Diagnostics.KIND,
-            error: Diagnostics.Argument_for_module_option_must_be_commonjs_amd_system_or_umd
+            error: Diagnostics.Argument_for_module_option_must_be_commonjs_amd_system_umd_or_es6
         },
         {
             name: "newLine",

src/compiler/diagnosticInformationMap.generated.ts

@@ -160,7 +160,7 @@ namespace ts {
         Line_terminator_not_permitted_before_arrow: { code: 1200, category: DiagnosticCategory.Error, key: "Line terminator not permitted before arrow." },
         Import_assignment_cannot_be_used_when_targeting_ECMAScript_6_or_higher_Consider_using_import_Asterisk_as_ns_from_mod_import_a_from_mod_or_import_d_from_mod_instead: { code: 1202, category: DiagnosticCategory.Error, key: "Import assignment cannot be used when targeting ECMAScript 6 or higher. Consider using 'import * as ns from \"mod\"', 'import {a} from \"mod\"' or 'import d from \"mod\"' instead." },
         Export_assignment_cannot_be_used_when_targeting_ECMAScript_6_or_higher_Consider_using_export_default_instead: { code: 1203, category: DiagnosticCategory.Error, key: "Export assignment cannot be used when targeting ECMAScript 6 or higher. Consider using 'export default' instead." },
-        Cannot_compile_modules_into_commonjs_amd_system_or_umd_when_targeting_ES6_or_higher: { code: 1204, category: DiagnosticCategory.Error, key: "Cannot compile modules into 'commonjs', 'amd', 'system' or 'umd' when targeting 'ES6' or higher." },
+        Cannot_compile_modules_into_es6_when_targeting_ES5_or_lower: { code: 1204, category: DiagnosticCategory.Error, key: "Cannot compile modules into 'es6' when targeting 'ES5' or lower." },
         Decorators_are_only_available_when_targeting_ECMAScript_5_and_higher: { code: 1205, category: DiagnosticCategory.Error, key: "Decorators are only available when targeting ECMAScript 5 and higher." },
         Decorators_are_not_valid_here: { code: 1206, category: DiagnosticCategory.Error, key: "Decorators are not valid here." },
         Decorators_cannot_be_applied_to_multiple_get_Slashset_accessors_of_the_same_name: { code: 1207, category: DiagnosticCategory.Error, key: "Decorators cannot be applied to multiple get/set accessors of the same name." },
@@ -528,7 +528,7 @@ namespace ts {
         Do_not_emit_comments_to_output: { code: 6009, category: DiagnosticCategory.Message, key: "Do not emit comments to output." },
         Do_not_emit_outputs: { code: 6010, category: DiagnosticCategory.Message, key: "Do not emit outputs." },
         Specify_ECMAScript_target_version_Colon_ES3_default_ES5_or_ES6_experimental: { code: 6015, category: DiagnosticCategory.Message, key: "Specify ECMAScript target version: 'ES3' (default), 'ES5', or 'ES6' (experimental)" },
-        Specify_module_code_generation_Colon_commonjs_amd_system_or_umd: { code: 6016, category: DiagnosticCategory.Message, key: "Specify module code generation: 'commonjs', 'amd', 'system' or 'umd'" },
+        Specify_module_code_generation_Colon_commonjs_amd_system_umd_or_es6: { code: 6016, category: DiagnosticCategory.Message, key: "Specify module code generation: 'commonjs', 'amd', 'system', 'umd' or 'es6'" },
         Print_this_message: { code: 6017, category: DiagnosticCategory.Message, key: "Print this message." },
         Print_the_compiler_s_version: { code: 6019, category: DiagnosticCategory.Message, key: "Print the compiler's version." },
         Compile_the_project_in_the_given_directory: { code: 6020, category: DiagnosticCategory.Message, key: "Compile the project in the given directory." },
@@ -549,7 +549,7 @@ namespace ts {
         Generates_corresponding_map_file: { code: 6043, category: DiagnosticCategory.Message, key: "Generates corresponding '.map' file." },
         Compiler_option_0_expects_an_argument: { code: 6044, category: DiagnosticCategory.Error, key: "Compiler option '{0}' expects an argument." },
         Unterminated_quoted_string_in_response_file_0: { code: 6045, category: DiagnosticCategory.Error, key: "Unterminated quoted string in response file '{0}'." },
-        Argument_for_module_option_must_be_commonjs_amd_system_or_umd: { code: 6046, category: DiagnosticCategory.Error, key: "Argument for '--module' option must be 'commonjs', 'amd', 'system' or 'umd'." },
+        Argument_for_module_option_must_be_commonjs_amd_system_umd_or_es6: { code: 6046, category: DiagnosticCategory.Error, key: "Argument for '--module' option must be 'commonjs', 'amd', 'system', 'umd', or 'es6'." },
         Argument_for_target_option_must_be_ES3_ES5_or_ES6: { code: 6047, category: DiagnosticCategory.Error, key: "Argument for '--target' option must be 'ES3', 'ES5', or 'ES6'." },
         Locale_must_be_of_the_form_language_or_language_territory_For_example_0_or_1: { code: 6048, category: DiagnosticCategory.Error, key: "Locale must be of the form <language> or <language>-<territory>. For example '{0}' or '{1}'." },
         Unsupported_locale_0: { code: 6049, category: DiagnosticCategory.Error, key: "Unsupported locale '{0}'." },

src/compiler/diagnosticMessages.json

@@ -627,7 +627,7 @@
         "category": "Error",
         "code": 1203
     },
-    "Cannot compile modules into 'commonjs', 'amd', 'system' or 'umd' when targeting 'ES6' or higher.": {
+    "Cannot compile modules into 'es6' when targeting 'ES5' or lower.": {
         "category": "Error",
         "code": 1204
     },
@@ -2102,7 +2102,7 @@
         "category": "Message",
         "code": 6015
     },
-    "Specify module code generation: 'commonjs', 'amd', 'system' or 'umd'": {
+    "Specify module code generation: 'commonjs', 'amd', 'system', 'umd' or 'es6'": {
         "category": "Message",
         "code": 6016
     },
@@ -2186,7 +2186,7 @@
         "category": "Error",
         "code": 6045
     },
-    "Argument for '--module' option must be 'commonjs', 'amd', 'system' or 'umd'.": {
+    "Argument for '--module' option must be 'commonjs', 'amd', 'system', 'umd', or 'es6'.": {
         "category": "Error",
         "code": 6046
     },

src/compiler/emitter.ts

@@ -188,6 +188,14 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
 
             /** If removeComments is true, no leading-comments needed to be emitted **/
             let emitLeadingCommentsOfPosition = compilerOptions.removeComments ? function (pos: number) { } : emitLeadingCommentsOfPositionWorker;
+
+            let moduleEmitDelegates: Map<(node: SourceFile, startIndex: number) => void> = {
+                [ModuleKind.ES6]: emitES6Module,
+                [ModuleKind.AMD]: emitAMDModule,
+                [ModuleKind.System]: emitSystemModule,
+                [ModuleKind.UMD]: emitUMDModule,
+                [ModuleKind.CommonJS]: emitCommonJSModule,
+            };
 
             if (compilerOptions.sourceMap || compilerOptions.inlineSourceMap) {
                 initializeEmitterWithSourceMaps();
@@ -1493,7 +1501,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                 if (container) {
                     if (container.kind === SyntaxKind.SourceFile) {
                         // Identifier references module export
-                        if (languageVersion < ScriptTarget.ES6 && compilerOptions.module !== ModuleKind.System) {
+                        if (compilerOptions.module !== ModuleKind.ES6 && compilerOptions.module !== ModuleKind.System) {
                             write("exports.");
                         }
                     }
@@ -1503,7 +1511,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                         write(".");
                     }
                 }
-                else if (languageVersion < ScriptTarget.ES6) {
+                else if (compilerOptions.module !== ModuleKind.ES6) {
                     let declaration = resolver.getReferencedImportDeclaration(node);
                     if (declaration) {
                         if (declaration.kind === SyntaxKind.ImportClause) {
@@ -3049,7 +3057,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                         write(getGeneratedNameForNode(container));
                         write(".");
                     }
-                    else if (languageVersion < ScriptTarget.ES6 && compilerOptions.module !== ModuleKind.System) {
+                    else if (compilerOptions.module !== ModuleKind.ES6 && compilerOptions.module !== ModuleKind.System) {
                         write("exports.");
                     }
                 }
@@ -3469,7 +3477,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
 
             function isES6ExportedDeclaration(node: Node) {
                 return !!(node.flags & NodeFlags.Export) &&
-                    languageVersion >= ScriptTarget.ES6 &&
+                    compilerOptions.module === ModuleKind.ES6 &&
                     node.parent.kind === SyntaxKind.SourceFile;
             }
 
@@ -5421,7 +5429,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
             }
 
             function emitImportDeclaration(node: ImportDeclaration) {
-                if (languageVersion < ScriptTarget.ES6) {
+                if (compilerOptions.module !== ModuleKind.ES6) {
                     return emitExternalImportDeclaration(node);
                 }
 
@@ -5586,7 +5594,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
             function emitExportDeclaration(node: ExportDeclaration) {
                 Debug.assert(compilerOptions.module !== ModuleKind.System);
 
-                if (languageVersion < ScriptTarget.ES6) {
+                if (compilerOptions.module !== ModuleKind.ES6) {
                     if (node.moduleSpecifier && (!node.exportClause || resolver.isValueAliasDeclaration(node))) {
                         emitStart(node);
                         let generatedName = getGeneratedNameForNode(node);
@@ -5652,7 +5660,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
             }
 
             function emitExportOrImportSpecifierList(specifiers: ImportOrExportSpecifier[], shouldEmit: (node: Node) => boolean) {
-                Debug.assert(languageVersion >= ScriptTarget.ES6);
+                Debug.assert(compilerOptions.module === ModuleKind.ES6);
 
                 let needsComma = false;
                 for (let specifier of specifiers) {
@@ -5672,7 +5680,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
 
             function emitExportAssignment(node: ExportAssignment) {
                 if (!node.isExportEquals && resolver.isValueAliasDeclaration(node)) {
-                    if (languageVersion >= ScriptTarget.ES6) {
+                    if (compilerOptions.module === ModuleKind.ES6) {
                         writeLine();
                         emitStart(node);
                         write("export default ");
@@ -6681,7 +6689,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                 }
             }
 
-            function emitSourceFileNode(node: SourceFile) {
+            function emitSourceFileNode(node: SourceFile) {                
                 // Start new file on new line
                 writeLine();
                 emitShebang();
@@ -6691,21 +6699,8 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                 let startIndex = emitDirectivePrologues(node.statements, /*startWithNewLine*/ false);
 
                 if (isExternalModule(node) || compilerOptions.isolatedModules) {
-                    if (languageVersion >= ScriptTarget.ES6) {
-                        emitES6Module(node, startIndex);
-                    }
-                    else if (compilerOptions.module === ModuleKind.AMD) {
-                        emitAMDModule(node, startIndex);
-                    }
-                    else if (compilerOptions.module === ModuleKind.System) {
-                        emitSystemModule(node, startIndex);
-                    }
-                    else if (compilerOptions.module === ModuleKind.UMD) {
-                        emitUMDModule(node, startIndex);
-                    }
-                    else {
-                        emitCommonJSModule(node, startIndex);
-                    }
+                    let emitModule = moduleEmitDelegates[compilerOptions.module] || moduleEmitDelegates[ModuleKind.CommonJS];
+                    emitModule(node, startIndex);
                 }
                 else {
                     externalImports = undefined;

src/compiler/program.ts

@@ -343,6 +343,10 @@ namespace ts {
         let classifiableNames: Map<string>;
 
         let skipDefaultLib = options.noLib;
+
+        if (options.target >= ScriptTarget.ES6 && !options.module) { // Preserve old ES6 module behavior
+            options.module = ModuleKind.ES6;
+        }
 
         let start = new Date().getTime();
 
@@ -1022,9 +1026,9 @@ namespace ts {
                 programDiagnostics.add(createFileDiagnostic(firstExternalModuleSourceFile, span.start, span.length, Diagnostics.Cannot_compile_modules_unless_the_module_flag_is_provided));
             }
 
-            // Cannot specify module gen target when in es6 or above
-            if (options.module && languageVersion >= ScriptTarget.ES6) {
-                programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Cannot_compile_modules_into_commonjs_amd_system_or_umd_when_targeting_ES6_or_higher));
+            // Cannot specify module gen target of es6 when below es6
+            if (options.module === ModuleKind.ES6 && languageVersion < ScriptTarget.ES6) {
+                programDiagnostics.add(createCompilerDiagnostic(Diagnostics.Cannot_compile_modules_into_es6_when_targeting_ES5_or_lower));
             }
 
             // there has to be common source directory if user specified --outdir || --sourceRoot

src/compiler/types.ts

@@ -2076,6 +2076,7 @@ namespace ts {
         AMD = 2,
         UMD = 3,
         System = 4,
+        ES6 = 5,
     }
 
     export const enum JsxEmit {

tests/baselines/reference/constDeclarations-access5.errors.txt

@@ -1,4 +1,3 @@
-error TS1204: Cannot compile modules into 'commonjs', 'amd', 'system' or 'umd' when targeting 'ES6' or higher.
 tests/cases/compiler/constDeclarations_access_2.ts(2,1): error TS1202: Import assignment cannot be used when targeting ECMAScript 6 or higher. Consider using 'import * as ns from "mod"', 'import {a} from "mod"' or 'import d from "mod"' instead.
 tests/cases/compiler/constDeclarations_access_2.ts(4,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
 tests/cases/compiler/constDeclarations_access_2.ts(5,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
@@ -20,7 +19,6 @@ tests/cases/compiler/constDeclarations_access_2.ts(22,3): error TS2449: The oper
 tests/cases/compiler/constDeclarations_access_2.ts(24,1): error TS2450: Left-hand side of assignment expression cannot be a constant.
 
 
-!!! error TS1204: Cannot compile modules into 'commonjs', 'amd', 'system' or 'umd' when targeting 'ES6' or higher.
 ==== tests/cases/compiler/constDeclarations_access_2.ts (19 errors) ====
     ///<reference path='constDeclarations_access_1.ts'/>
     import m = require('constDeclarations_access_1');

tests/baselines/reference/constDeclarations-access5.js

@@ -49,35 +49,39 @@ m.x.toString();
 
 
 //// [constDeclarations_access_1.js]
-export const x = 0;
+define(["require", "exports"], function (require, exports) {
+    exports.x = 0;
+});
 //// [constDeclarations_access_2.js]
-// Errors
-m.x = 1;
-m.x += 2;
-m.x -= 3;
-m.x *= 4;
-m.x /= 5;
-m.x %= 6;
-m.x <<= 7;
-m.x >>= 8;
-m.x >>>= 9;
-m.x &= 10;
-m.x |= 11;
-m.x ^= 12;
-m;
-m.x++;
-m.x--;
-++m.x;
---m.x;
-++((m.x));
-m["x"] = 0;
-// OK
-var a = m.x + 1;
-function f(v) { }
-f(m.x);
-if (m.x) { }
-m.x;
-(m.x);
--m.x;
-+m.x;
-m.x.toString();
+define(["require", "exports", 'constDeclarations_access_1'], function (require, exports, m) {
+    // Errors
+    m.x = 1;
+    m.x += 2;
+    m.x -= 3;
+    m.x *= 4;
+    m.x /= 5;
+    m.x %= 6;
+    m.x <<= 7;
+    m.x >>= 8;
+    m.x >>>= 9;
+    m.x &= 10;
+    m.x |= 11;
+    m.x ^= 12;
+    m;
+    m.x++;
+    m.x--;
+    ++m.x;
+    --m.x;
+    ++((m.x));
+    m["x"] = 0;
+    // OK
+    var a = m.x + 1;
+    function f(v) { }
+    f(m.x);
+    if (m.x) { }
+    m.x;
+    (m.x);
+    -m.x;
+    +m.x;
+    m.x.toString();
+});

tests/baselines/reference/es5andes6module.errors.txt

@@ -0,0 +1,19 @@
+error TS1204: Cannot compile modules into 'es6' when targeting 'ES5' or lower.
+
+
+!!! error TS1204: Cannot compile modules into 'es6' when targeting 'ES5' or lower.
+==== tests/cases/compiler/es5andes6module.ts (0 errors) ====
+
+    export default class A
+    {
+        constructor ()
+        {
+
+        }
+
+        public B()
+        {
+            return 42;
+        }
+    }
+

tests/baselines/reference/es5andes6module.js

@@ -0,0 +1,26 @@
+//// [es5andes6module.ts]
+
+export default class A
+{
+    constructor ()
+    {
+
+    }
+
+    public B()
+    {
+        return 42;
+    }
+}
+
+
+//// [es5andes6module.js]
+var A = (function () {
+    function A() {
+    }
+    A.prototype.B = function () {
+        return 42;
+    };
+    return A;
+})();
+exports.default = A;

tests/baselines/reference/es6-amd.symbols

@@ -0,0 +1,16 @@
+=== tests/cases/compiler/es6-amd.ts ===
+
+class A
+>A : Symbol(A, Decl(es6-amd.ts, 0, 0))
+{
+    constructor ()
+    {
+
+    }
+
+    public B()
+>B : Symbol(B, Decl(es6-amd.ts, 6, 5))
+    {
+        return 42;
+    }
+}