Fix #6319: Add support for --t: es5 and --m es6

src/compiler/diagnosticMessages.json

@@ -635,10 +635,6 @@
         "category": "Error",
         "code": 1203
     },
-    "Cannot compile modules into 'es2015' when targeting 'ES5' or lower.": {
-        "category": "Error",
-        "code": 1204
-    },
     "Decorators are not valid here.": {
         "category": "Error",
         "code": 1206

src/compiler/emitter.ts

@@ -5559,7 +5559,11 @@ const _super = (function (geti, seti) {
             }
 
             function emitClassLikeDeclarationBelowES6(node: ClassLikeDeclaration) {
+                const isES6ExportedClass = isES6ExportedDeclaration(node);
                 if (node.kind === SyntaxKind.ClassDeclaration) {
+                    if (isES6ExportedClass && !(node.flags & NodeFlags.Default)) {
+                        write("export ");
+                    }
                     // source file level classes in system modules are hoisted so 'var's for them are already defined
                     if (!shouldHoistDeclarationInSystemJsModule(node)) {
                         write("var ");
@@ -5629,9 +5633,15 @@ const _super = (function (geti, seti) {
                 }
                 emitEnd(node);
 
-                if (node.kind === SyntaxKind.ClassDeclaration) {
+                if (node.kind === SyntaxKind.ClassDeclaration && !isES6ExportedClass) {
                     emitExportMemberAssignment(<ClassDeclaration>node);
                 }
+                else if (isES6ExportedClass && (node.flags & NodeFlags.Default)) {
+                    writeLine();
+                    write("export default ");
+                    emitDeclarationName(node);
+                    write(";");
+                }
             }
 
             function emitClassMemberPrefix(node: ClassLikeDeclaration, member: Node) {

src/compiler/program.ts

@@ -2099,11 +2099,6 @@ namespace ts {
                 programDiagnostics.add(createFileDiagnostic(firstExternalModuleSourceFile, span.start, span.length, Diagnostics.Cannot_use_imports_exports_or_module_augmentations_when_module_is_none));
             }
 
-            // 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_es2015_when_targeting_ES5_or_lower));
-            }
-
             // Cannot specify module gen that isn't amd or system with --out
             if (outFile) {
                 if (options.module && !(options.module === ModuleKind.AMD || options.module === ModuleKind.System)) {

tests/baselines/reference/es5andes6module.js

@@ -23,4 +23,4 @@ var A = (function () {
     };
     return A;
 }());
-exports.default = A;
+export default A;

tests/baselines/reference/es5andes6module.symbols

@@ -0,0 +1,17 @@
+=== tests/cases/compiler/es5andes6module.ts ===
+
+export default class A
+>A : Symbol(A, Decl(es5andes6module.ts, 0, 0))
+{
+    constructor ()
+    {
+
+    }
+
+    public B()
+>B : Symbol(A.B, Decl(es5andes6module.ts, 6, 5))
+    {
+        return 42;
+    }
+}
+

tests/baselines/reference/es5andes6module.types

@@ -0,0 +1,18 @@
+=== tests/cases/compiler/es5andes6module.ts ===
+
+export default class A
+>A : A
+{
+    constructor ()
+    {
+
+    }
+
+    public B()
+>B : () => number
+    {
+        return 42;
+>42 : number
+    }
+}
+

tests/baselines/reference/es6modulekindWithES5Target.js

@@ -0,0 +1,56 @@
+//// [es6modulekindWithES5Target.ts]
+
+export class C {
+    static s = 0;
+    p = 1;
+    method() { }
+}
+export { C as C2 };
+
+declare function foo(...args: any[]): any;
+@foo
+export class D {
+    static s = 0;
+    p = 1;
+    method() { }
+}
+export { D as D2 };
+
+class E { }
+export {E};
+
+
+//// [es6modulekindWithES5Target.js]
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+export var C = (function () {
+    function C() {
+        this.p = 1;
+    }
+    C.prototype.method = function () { };
+    C.s = 0;
+    return C;
+}());
+export { C as C2 };
+export var D = (function () {
+    function D() {
+        this.p = 1;
+    }
+    D.prototype.method = function () { };
+    D.s = 0;
+    D = __decorate([
+        foo
+    ], D);
+    return D;
+}());
+export { D as D2 };
+var E = (function () {
+    function E() {
+    }
+    return E;
+}());
+export { E };

tests/baselines/reference/es6modulekindWithES5Target.symbols

@@ -0,0 +1,47 @@
+=== tests/cases/compiler/es6modulekindWithES5Target.ts ===
+
+export class C {
+>C : Symbol(C, Decl(es6modulekindWithES5Target.ts, 0, 0))
+
+    static s = 0;
+>s : Symbol(C.s, Decl(es6modulekindWithES5Target.ts, 1, 16))
+
+    p = 1;
+>p : Symbol(C.p, Decl(es6modulekindWithES5Target.ts, 2, 17))
+
+    method() { }
+>method : Symbol(C.method, Decl(es6modulekindWithES5Target.ts, 3, 10))
+}
+export { C as C2 };
+>C : Symbol(C2, Decl(es6modulekindWithES5Target.ts, 6, 8))
+>C2 : Symbol(C2, Decl(es6modulekindWithES5Target.ts, 6, 8))
+
+declare function foo(...args: any[]): any;
+>foo : Symbol(foo, Decl(es6modulekindWithES5Target.ts, 6, 19))
+>args : Symbol(args, Decl(es6modulekindWithES5Target.ts, 8, 21))
+
+@foo
+>foo : Symbol(foo, Decl(es6modulekindWithES5Target.ts, 6, 19))
+
+export class D {
+>D : Symbol(D, Decl(es6modulekindWithES5Target.ts, 8, 42))
+
+    static s = 0;
+>s : Symbol(D.s, Decl(es6modulekindWithES5Target.ts, 10, 16))
+
+    p = 1;
+>p : Symbol(D.p, Decl(es6modulekindWithES5Target.ts, 11, 17))
+
+    method() { }
+>method : Symbol(D.method, Decl(es6modulekindWithES5Target.ts, 12, 10))
+}
+export { D as D2 };
+>D : Symbol(D2, Decl(es6modulekindWithES5Target.ts, 15, 8))
+>D2 : Symbol(D2, Decl(es6modulekindWithES5Target.ts, 15, 8))
+
+class E { }
+>E : Symbol(E, Decl(es6modulekindWithES5Target.ts, 15, 19))
+
+export {E};
+>E : Symbol(E, Decl(es6modulekindWithES5Target.ts, 18, 8))
+

tests/baselines/reference/es6modulekindWithES5Target.types

@@ -0,0 +1,51 @@
+=== tests/cases/compiler/es6modulekindWithES5Target.ts ===
+
+export class C {
+>C : C
+
+    static s = 0;
+>s : number
+>0 : number
+
+    p = 1;
+>p : number
+>1 : number
+
+    method() { }
+>method : () => void
+}
+export { C as C2 };
+>C : typeof C
+>C2 : typeof C
+
+declare function foo(...args: any[]): any;
+>foo : (...args: any[]) => any
+>args : any[]
+
+@foo
+>foo : (...args: any[]) => any
+
+export class D {
+>D : D
+
+    static s = 0;
+>s : number
+>0 : number
+
+    p = 1;
+>p : number
+>1 : number
+
+    method() { }
+>method : () => void
+}
+export { D as D2 };
+>D : typeof D
+>D2 : typeof D
+
+class E { }
+>E : E
+
+export {E};
+>E : typeof E
+

tests/baselines/reference/es6modulekindWithES5Target10.errors.txt

@@ -0,0 +1,19 @@
+tests/cases/compiler/es6modulekindWithES5Target10.ts(2,1): error TS1202: Import assignment cannot be used when targeting ECMAScript 6 modules. Consider using 'import * as ns from "mod"', 'import {a} from "mod"', 'import d from "mod"', or another module format instead.
+tests/cases/compiler/es6modulekindWithES5Target10.ts(2,20): error TS2307: Cannot find module 'mod'.
+tests/cases/compiler/es6modulekindWithES5Target10.ts(7,1): error TS1203: Export assignment cannot be used when targeting ECMAScript 6 modules. Consider using 'export default' or another module format instead.
+
+
+==== tests/cases/compiler/es6modulekindWithES5Target10.ts (3 errors) ====
+
+    import i = require("mod"); // Error;
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS1202: Import assignment cannot be used when targeting ECMAScript 6 modules. Consider using 'import * as ns from "mod"', 'import {a} from "mod"', 'import d from "mod"', or another module format instead.
+                       ~~~~~
+!!! error TS2307: Cannot find module 'mod'.
+
+
+    namespace N {
+    }
+    export = N; // Error
+    ~~~~~~~~~~~
+!!! error TS1203: Export assignment cannot be used when targeting ECMAScript 6 modules. Consider using 'export default' or another module format instead.

tests/baselines/reference/es6modulekindWithES5Target10.js

@@ -0,0 +1,10 @@
+//// [es6modulekindWithES5Target10.ts]
+
+import i = require("mod"); // Error;
+
+
+namespace N {
+}
+export = N; // Error
+
+//// [es6modulekindWithES5Target10.js]

tests/baselines/reference/es6modulekindWithES5Target11.js

@@ -0,0 +1,31 @@
+//// [es6modulekindWithES5Target11.ts]
+
+declare function foo(...args: any[]): any;
+@foo
+export default class C {
+    static x() { return C.y; }
+    static y = 1
+    p = 1;
+    method() { }
+}
+
+//// [es6modulekindWithES5Target11.js]
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var C = (function () {
+    function C() {
+        this.p = 1;
+    }
+    C.x = function () { return C.y; };
+    C.prototype.method = function () { };
+    C.y = 1;
+    C = __decorate([
+        foo
+    ], C);
+    return C;
+}());
+export default C;

tests/baselines/reference/es6modulekindWithES5Target11.symbols

@@ -0,0 +1,27 @@
+=== tests/cases/compiler/es6modulekindWithES5Target11.ts ===
+
+declare function foo(...args: any[]): any;
+>foo : Symbol(foo, Decl(es6modulekindWithES5Target11.ts, 0, 0))
+>args : Symbol(args, Decl(es6modulekindWithES5Target11.ts, 1, 21))
+
+@foo
+>foo : Symbol(foo, Decl(es6modulekindWithES5Target11.ts, 0, 0))
+
+export default class C {
+>C : Symbol(C, Decl(es6modulekindWithES5Target11.ts, 1, 42))
+
+    static x() { return C.y; }
+>x : Symbol(C.x, Decl(es6modulekindWithES5Target11.ts, 3, 24))
+>C.y : Symbol(C.y, Decl(es6modulekindWithES5Target11.ts, 4, 30))
+>C : Symbol(C, Decl(es6modulekindWithES5Target11.ts, 1, 42))
+>y : Symbol(C.y, Decl(es6modulekindWithES5Target11.ts, 4, 30))
+
+    static y = 1
+>y : Symbol(C.y, Decl(es6modulekindWithES5Target11.ts, 4, 30))
+
+    p = 1;
+>p : Symbol(C.p, Decl(es6modulekindWithES5Target11.ts, 5, 16))
+
+    method() { }
+>method : Symbol(C.method, Decl(es6modulekindWithES5Target11.ts, 6, 10))
+}

tests/baselines/reference/es6modulekindWithES5Target11.types

@@ -0,0 +1,29 @@
+=== tests/cases/compiler/es6modulekindWithES5Target11.ts ===
+
+declare function foo(...args: any[]): any;
+>foo : (...args: any[]) => any
+>args : any[]
+
+@foo
+>foo : (...args: any[]) => any
+
+export default class C {
+>C : C
+
+    static x() { return C.y; }
+>x : () => number
+>C.y : number
+>C : typeof C
+>y : number
+
+    static y = 1
+>y : number
+>1 : number
+
+    p = 1;
+>p : number
+>1 : number
+
+    method() { }
+>method : () => void
+}