Merge branch 'master' into reachabilityChecks

Jakefile.js

@@ -813,7 +813,6 @@ task("update-sublime", ["local", serverFile], function() {
 var tslintRuleDir = "scripts/tslint";
 var tslintRules = ([
     "nextLineRule",
-    "noInferrableTypesRule",
     "noNullRule",
     "booleanTriviaRule"
 ]);

scripts/tslint/noInferrableTypesRule.ts

@@ -1,49 +0,0 @@
-/// <reference path="../../node_modules/tslint/typings/typescriptServices.d.ts" />
-/// <reference path="../../node_modules/tslint/lib/tslint.d.ts" />
-
-
-export class Rule extends Lint.Rules.AbstractRule {
-    public static FAILURE_STRING_FACTORY = (type: string) => `LHS type (${type}) inferred by RHS expression, remove type annotation`;
-
-    public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
-        return this.applyWithWalker(new InferrableTypeWalker(sourceFile, this.getOptions()));
-    }
-}
-
-class InferrableTypeWalker extends Lint.RuleWalker {
-    visitVariableStatement(node: ts.VariableStatement) {
-        node.declarationList.declarations.forEach(e => {
-            if ((!!e.type) && (!!e.initializer)) {
-                let failure: string;
-                switch (e.type.kind) {
-                    case ts.SyntaxKind.BooleanKeyword:
-                        if (e.initializer.kind === ts.SyntaxKind.TrueKeyword || e.initializer.kind === ts.SyntaxKind.FalseKeyword) {
-                            failure = 'boolean';
-                        }
-                    break;
-                    case ts.SyntaxKind.NumberKeyword:
-                        if (e.initializer.kind === ts.SyntaxKind.NumericLiteral) {
-                            failure = 'number';
-                        }
-                    break;
-                    case ts.SyntaxKind.StringKeyword:
-                        switch (e.initializer.kind) {
-                            case ts.SyntaxKind.StringLiteral:
-                            case ts.SyntaxKind.NoSubstitutionTemplateLiteral:
-                            case ts.SyntaxKind.TemplateExpression:
-                                failure = 'string';
-                                break;
-                            default:
-                                break;
-                        }
-                    break;
-                }
-                if (failure) {
-                    this.addFailure(this.createFailure(e.type.getStart(), e.type.getWidth(), Rule.FAILURE_STRING_FACTORY(failure)));
-                }
-            }
-        });
-
-        super.visitVariableStatement(node);
-    }
-}

src/compiler/checker.ts

@@ -8565,6 +8565,12 @@ namespace ts {
                     case SyntaxKind.SetAccessor:
                         // A method or accessor declaration decorator will have two or three arguments (see
                         // `PropertyDecorator` and `MethodDecorator` in core.d.ts)
+
+                        // If we are emitting decorators for ES3, we will only pass two arguments. 
+                        if (languageVersion === ScriptTarget.ES3) {
+                            return 2;
+                        }
+
                         // If the method decorator signature only accepts a target and a key, we will only
                         // type check those arguments.
                         return signature.parameters.length >= 3 ? 3 : 2;
@@ -14909,9 +14915,6 @@ namespace ts {
             if (!nodeCanBeDecorated(node)) {
                 return grammarErrorOnFirstToken(node, Diagnostics.Decorators_are_not_valid_here);
             }
-            else if (languageVersion < ScriptTarget.ES5) {
-                return grammarErrorOnFirstToken(node, Diagnostics.Decorators_are_only_available_when_targeting_ECMAScript_5_and_higher);
-            }
             else if (node.kind === SyntaxKind.GetAccessor || node.kind === SyntaxKind.SetAccessor) {
                 let accessors = getAllAccessorDeclarations((<ClassDeclaration>node.parent).members, <AccessorDeclaration>node);
                 if (accessors.firstAccessor.decorators && node === accessors.secondAccessor) {

src/compiler/diagnosticMessages.json

@@ -631,10 +631,6 @@
         "category": "Error",
         "code": 1204
     },
-    "Decorators are only available when targeting ECMAScript 5 and higher.": {
-        "category": "Error",
-        "code": 1205
-    },
     "Decorators are not valid here.": {
         "category": "Error",
         "code": 1206

src/compiler/emitter.ts

@@ -285,12 +285,10 @@ var __extends = (this && this.__extends) || function (d, b) {
         // emit output for the __decorate helper function
         const decorateHelper = `
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };`;
 
         // emit output for the __metadata helper function
@@ -1652,7 +1650,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                     //
                     // The emit for the decorated computed property decorator is:
                     //
-                    //   Object.defineProperty(C.prototype, _a, __decorate([dec], C.prototype, _a, Object.getOwnPropertyDescriptor(C.prototype, _a)));
+                    //   __decorate([dec], C.prototype, _a, Object.getOwnPropertyDescriptor(C.prototype, _a));
                     //
                     if (nodeIsDecorated(node.parent)) {
                         if (!computedPropertyNamesToGeneratedNames) {
@@ -4707,7 +4705,6 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                         //
                         //     let C = class {
                         //     };
-                        //     Object.defineProperty(C, "name", { value: "C", configurable: true });
                         //     C = __decorate([dec], C);
                         //
                         // * For an exported class declaration:
@@ -4719,7 +4716,6 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                         //
                         //     export let C = class {
                         //     };
-                        //     Object.defineProperty(C, "name", { value: "C", configurable: true });
                         //     C = __decorate([dec], C);
                         //
                         // * For a default export of a class declaration with a name:
@@ -4731,7 +4727,6 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                         //
                         //     let C = class {
                         //     }
-                        //     Object.defineProperty(C, "name", { value: "C", configurable: true });
                         //     C = __decorate([dec], C);
                         //     export default C;
                         //
@@ -5059,21 +5054,19 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                     //
                     // The emit for a method is:
                     //
-                    //   Object.defineProperty(C.prototype, "method",
-                    //       __decorate([
-                    //           dec,
-                    //           __param(0, dec2),
-                    //           __metadata("design:type", Function),
-                    //           __metadata("design:paramtypes", [Object]),
-                    //           __metadata("design:returntype", void 0)
-                    //       ], C.prototype, "method", Object.getOwnPropertyDescriptor(C.prototype, "method")));
+                    //   __decorate([
+                    //       dec,
+                    //       __param(0, dec2),
+                    //       __metadata("design:type", Function),
+                    //       __metadata("design:paramtypes", [Object]),
+                    //       __metadata("design:returntype", void 0)
+                    //   ], C.prototype, "method", undefined);
                     //
                     // The emit for an accessor is:
                     //
-                    //   Object.defineProperty(C.prototype, "accessor",
-                    //       __decorate([
-                    //           dec
-                    //       ], C.prototype, "accessor", Object.getOwnPropertyDescriptor(C.prototype, "accessor")));
+                    //   __decorate([
+                    //       dec
+                    //   ], C.prototype, "accessor", undefined);
                     //
                     // The emit for a property is:
                     //
@@ -5084,18 +5077,6 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
 
                     writeLine();
                     emitStart(member);
-                    if (member.kind !== SyntaxKind.PropertyDeclaration) {
-                        write("Object.defineProperty(");
-                        emitStart(member.name);
-                        emitClassMemberPrefix(node, member);
-                        write(", ");
-                        emitExpressionForPropertyName(member.name);
-                        emitEnd(member.name);
-                        write(",");
-                        increaseIndent();
-                        writeLine();
-                    }
-
                     write("__decorate([");
                     increaseIndent();
                     writeLine();
@@ -5119,15 +5100,17 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
                     emitExpressionForPropertyName(member.name);
                     emitEnd(member.name);
 
-                    if (member.kind !== SyntaxKind.PropertyDeclaration) {
-                        write(", Object.getOwnPropertyDescriptor(");
-                        emitStart(member.name);
-                        emitClassMemberPrefix(node, member);
-                        write(", ");
-                        emitExpressionForPropertyName(member.name);
-                        emitEnd(member.name);
-                        write("))");
-                        decreaseIndent();
+                    if (languageVersion > ScriptTarget.ES3) {
+                        if (member.kind !== SyntaxKind.PropertyDeclaration) {
+                            // We emit `null` here to indicate to `__decorate` that it can invoke `Object.getOwnPropertyDescriptor` directly.
+                            // We have this extra argument here so that we can inject an explicit property descriptor at a later date.
+                            write(", null");
+                        }
+                        else {
+                            // We emit `void 0` here to indicate to `__decorate` that it can invoke `Object.defineProperty` directly, but that it
+                            // should not invoke `Object.getOwnPropertyDescriptor`.
+                            write(", void 0");
+                        }
                     }
 
                     write(");");

src/compiler/utilities.ts

@@ -985,6 +985,7 @@ namespace ts {
                         return node === (<ComputedPropertyName>parent).expression;
                     case SyntaxKind.Decorator:
                     case SyntaxKind.JsxExpression:
+                    case SyntaxKind.JsxSpreadAttribute:
                         return true;
                     case SyntaxKind.ExpressionWithTypeArguments:
                         return (<ExpressionWithTypeArguments>parent).expression === node && isExpressionWithTypeArgumentsInClassExtendsClause(parent);

src/harness/fourslash.ts

@@ -157,7 +157,7 @@ namespace FourSlash {
             return true;
         }
 
-        public setCancelled(numberOfCalls: number = 0): void {
+        public setCancelled(numberOfCalls = 0): void {
             ts.Debug.assert(numberOfCalls >= 0);
             this.numberOfCallsBeforeCancellation = numberOfCalls;
         }
@@ -761,7 +761,7 @@ namespace FourSlash {
             this.raiseError(`verifyReferencesAtPositionListContains failed - could not find the item: ${JSON.stringify(missingItem)} in the returned list: (${JSON.stringify(references)})`);
         }
 
-        public verifyReferencesCountIs(count: number, localFilesOnly: boolean = true) {
+        public verifyReferencesCountIs(count: number, localFilesOnly = true) {
             this.taoInvalidReason = "verifyReferences NYI";
 
             let references = this.getReferencesAtCaret();

tests/baselines/reference/classExpressionWithDecorator1.js

@@ -3,12 +3,10 @@ var v = @decorate class C { static p = 1 };
 
 //// [classExpressionWithDecorator1.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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 v = ;
 var C = (function () {

tests/baselines/reference/decoratedClassFromExternalModule.js

@@ -11,12 +11,10 @@ import Decorated from 'decorated';
 
 //// [decorated.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };
 function decorate(target) { }
 let Decorated = class {

tests/baselines/reference/decoratorChecksFunctionBodies.js

@@ -17,12 +17,10 @@ class A {
 
 //// [decoratorChecksFunctionBodies.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };
 // from #2971
 function func(s) {
@@ -32,13 +30,12 @@ var A = (function () {
     }
     A.prototype.m = function () {
     };
-    Object.defineProperty(A.prototype, "m",
-        __decorate([
-            (function (x, p) {
-                var a = 3;
-                func(a);
-                return x;
-            })
-        ], A.prototype, "m", Object.getOwnPropertyDescriptor(A.prototype, "m")));
+    __decorate([
+        (function (x, p) {
+            var a = 3;
+            func(a);
+            return x;
+        })
+    ], A.prototype, "m", null);
     return A;
 })();

tests/baselines/reference/decoratorInstantiateModulesInFunctionBodies.js

@@ -26,12 +26,10 @@ class Wat {
 exports.test = 'abc';
 //// [b.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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 a_1 = require('./a');
 function filter(handler) {
@@ -45,9 +43,8 @@ var Wat = (function () {
     Wat.whatever = function () {
         // ...
     };
-    Object.defineProperty(Wat, "whatever",
-        __decorate([
-            filter(function () { return a_1.test == 'abc'; })
-        ], Wat, "whatever", Object.getOwnPropertyDescriptor(Wat, "whatever")));
+    __decorate([
+        filter(function () { return a_1.test == 'abc'; })
+    ], Wat, "whatever", null);
     return Wat;
 })();

tests/baselines/reference/decoratorMetadata.js

@@ -24,12 +24,10 @@ Object.defineProperty(exports, "__esModule", { value: true });
 exports.default = Service;
 //// [component.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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 __metadata = (this && this.__metadata) || function (k, v) {
     if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);

tests/baselines/reference/decoratorMetadataForMethodWithNoReturnTypeAnnotation01.js

@@ -20,12 +20,11 @@ var MyClass = (function () {
     }
     MyClass.prototype.doSomething = function () {
     };
-    Object.defineProperty(MyClass.prototype, "doSomething",
-        __decorate([
-            decorator, 
-            __metadata('design:type', Function), 
-            __metadata('design:paramtypes', []), 
-            __metadata('design:returntype', void 0)
-        ], MyClass.prototype, "doSomething", Object.getOwnPropertyDescriptor(MyClass.prototype, "doSomething")));
+    __decorate([
+        decorator, 
+        __metadata('design:type', Function), 
+        __metadata('design:paramtypes', []), 
+        __metadata('design:returntype', void 0)
+    ], MyClass.prototype, "doSomething", null);
     return MyClass;
 })();

tests/baselines/reference/decoratorMetadataOnInferredType.js

@@ -33,7 +33,7 @@ var B = (function () {
     __decorate([
         decorator, 
         __metadata('design:type', Object)
-    ], B.prototype, "x");
+    ], B.prototype, "x", void 0);
     return B;
 })();
 exports.B = B;

tests/baselines/reference/decoratorMetadataWithConstructorType.js

@@ -33,7 +33,7 @@ var B = (function () {
     __decorate([
         decorator, 
         __metadata('design:type', A)
-    ], B.prototype, "x");
+    ], B.prototype, "x", void 0);
     return B;
 })();
 exports.B = B;

tests/baselines/reference/decoratorOnClass1.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClass1.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {

tests/baselines/reference/decoratorOnClass2.js

@@ -7,12 +7,10 @@ export class C {
 
 //// [decoratorOnClass2.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {

tests/baselines/reference/decoratorOnClass3.js

@@ -8,12 +8,10 @@ class C {
 
 //// [decoratorOnClass3.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {

tests/baselines/reference/decoratorOnClass4.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClass4.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {

tests/baselines/reference/decoratorOnClass5.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClass5.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {

tests/baselines/reference/decoratorOnClass8.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClass8.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {

tests/baselines/reference/decoratorOnClassAccessor1.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClassAccessor1.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
@@ -22,9 +20,8 @@ var C = (function () {
         enumerable: true,
         configurable: true
     });
-    Object.defineProperty(C.prototype, "accessor",
-        __decorate([
-            dec
-        ], C.prototype, "accessor", Object.getOwnPropertyDescriptor(C.prototype, "accessor")));
+    __decorate([
+        dec
+    ], C.prototype, "accessor", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassAccessor2.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClassAccessor2.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
@@ -22,9 +20,8 @@ var C = (function () {
         enumerable: true,
         configurable: true
     });
-    Object.defineProperty(C.prototype, "accessor",
-        __decorate([
-            dec
-        ], C.prototype, "accessor", Object.getOwnPropertyDescriptor(C.prototype, "accessor")));
+    __decorate([
+        dec
+    ], C.prototype, "accessor", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassAccessor3.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClassAccessor3.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
@@ -22,9 +20,8 @@ var C = (function () {
         enumerable: true,
         configurable: true
     });
-    Object.defineProperty(C.prototype, "accessor",
-        __decorate([
-            dec
-        ], C.prototype, "accessor", Object.getOwnPropertyDescriptor(C.prototype, "accessor")));
+    __decorate([
+        dec
+    ], C.prototype, "accessor", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassAccessor4.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClassAccessor4.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
@@ -22,9 +20,8 @@ var C = (function () {
         enumerable: true,
         configurable: true
     });
-    Object.defineProperty(C.prototype, "accessor",
-        __decorate([
-            dec
-        ], C.prototype, "accessor", Object.getOwnPropertyDescriptor(C.prototype, "accessor")));
+    __decorate([
+        dec
+    ], C.prototype, "accessor", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassAccessor5.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClassAccessor5.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
@@ -22,9 +20,8 @@ var C = (function () {
         enumerable: true,
         configurable: true
     });
-    Object.defineProperty(C.prototype, "accessor",
-        __decorate([
-            dec
-        ], C.prototype, "accessor", Object.getOwnPropertyDescriptor(C.prototype, "accessor")));
+    __decorate([
+        dec
+    ], C.prototype, "accessor", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassAccessor6.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClassAccessor6.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
@@ -22,9 +20,8 @@ var C = (function () {
         enumerable: true,
         configurable: true
     });
-    Object.defineProperty(C.prototype, "accessor",
-        __decorate([
-            dec
-        ], C.prototype, "accessor", Object.getOwnPropertyDescriptor(C.prototype, "accessor")));
+    __decorate([
+        dec
+    ], C.prototype, "accessor", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassConstructorParameter1.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClassConstructorParameter1.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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 __param = (this && this.__param) || function (paramIndex, decorator) {
     return function (target, key) { decorator(target, key, paramIndex); }

tests/baselines/reference/decoratorOnClassConstructorParameter4.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClassConstructorParameter4.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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 __param = (this && this.__param) || function (paramIndex, decorator) {
     return function (target, key) { decorator(target, key, paramIndex); }

tests/baselines/reference/decoratorOnClassMethod1.js

@@ -7,20 +7,17 @@ class C {
 
 //// [decoratorOnClassMethod1.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     C.prototype.method = function () { };
-    Object.defineProperty(C.prototype, "method",
-        __decorate([
-            dec
-        ], C.prototype, "method", Object.getOwnPropertyDescriptor(C.prototype, "method")));
+    __decorate([
+        dec
+    ], C.prototype, "method", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassMethod10.js

@@ -7,20 +7,17 @@ class C {
 
 //// [decoratorOnClassMethod10.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     C.prototype.method = function () { };
-    Object.defineProperty(C.prototype, "method",
-        __decorate([
-            dec
-        ], C.prototype, "method", Object.getOwnPropertyDescriptor(C.prototype, "method")));
+    __decorate([
+        dec
+    ], C.prototype, "method", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassMethod11.js

@@ -10,12 +10,10 @@ module M {
 
 //// [decoratorOnClassMethod11.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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 M;
 (function (M) {
@@ -24,10 +22,9 @@ var M;
         }
         C.prototype.decorator = function (target, key) { };
         C.prototype.method = function () { };
-        Object.defineProperty(C.prototype, "method",
-            __decorate([
-                this.decorator
-            ], C.prototype, "method", Object.getOwnPropertyDescriptor(C.prototype, "method")));
+        __decorate([
+            this.decorator
+        ], C.prototype, "method", null);
         return C;
     })();
 })(M || (M = {}));

tests/baselines/reference/decoratorOnClassMethod12.js

@@ -16,12 +16,10 @@ var __extends = (this && this.__extends) || function (d, b) {
     d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
 };
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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 M;
 (function (M) {
@@ -37,10 +35,9 @@ var M;
             _super.apply(this, arguments);
         }
         C.prototype.method = function () { };
-        Object.defineProperty(C.prototype, "method",
-            __decorate([
-                _super.decorator
-            ], C.prototype, "method", Object.getOwnPropertyDescriptor(C.prototype, "method")));
+        __decorate([
+            _super.decorator
+        ], C.prototype, "method", null);
         return C;
     })(S);
 })(M || (M = {}));

tests/baselines/reference/decoratorOnClassMethod13.js

@@ -8,23 +8,19 @@ class C {
 
 //// [decoratorOnClassMethod13.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };
 class C {
     [_a = "1"]() { }
     [_b = "b"]() { }
 }
-Object.defineProperty(C.prototype, _a,
-    __decorate([
-        dec
-    ], C.prototype, _a, Object.getOwnPropertyDescriptor(C.prototype, _a)));
-Object.defineProperty(C.prototype, _b,
-    __decorate([
-        dec
-    ], C.prototype, _b, Object.getOwnPropertyDescriptor(C.prototype, _b)));
+__decorate([
+    dec
+], C.prototype, _a, null);
+__decorate([
+    dec
+], C.prototype, _b, null);
 var _a, _b;

tests/baselines/reference/decoratorOnClassMethod2.js

@@ -7,20 +7,17 @@ class C {
 
 //// [decoratorOnClassMethod2.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     C.prototype.method = function () { };
-    Object.defineProperty(C.prototype, "method",
-        __decorate([
-            dec
-        ], C.prototype, "method", Object.getOwnPropertyDescriptor(C.prototype, "method")));
+    __decorate([
+        dec
+    ], C.prototype, "method", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassMethod3.js

@@ -7,20 +7,17 @@ class C {
 
 //// [decoratorOnClassMethod3.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     C.prototype.method = function () { };
-    Object.defineProperty(C.prototype, "method",
-        __decorate([
-            dec
-        ], C.prototype, "method", Object.getOwnPropertyDescriptor(C.prototype, "method")));
+    __decorate([
+        dec
+    ], C.prototype, "method", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassMethod4.js

@@ -7,18 +7,15 @@ class C {
 
 //// [decoratorOnClassMethod4.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };
 class C {
     [_a = "method"]() { }
 }
-Object.defineProperty(C.prototype, _a,
-    __decorate([
-        dec
-    ], C.prototype, _a, Object.getOwnPropertyDescriptor(C.prototype, _a)));
+__decorate([
+    dec
+], C.prototype, _a, null);
 var _a;

tests/baselines/reference/decoratorOnClassMethod5.js

@@ -7,18 +7,15 @@ class C {
 
 //// [decoratorOnClassMethod5.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };
 class C {
     [_a = "method"]() { }
 }
-Object.defineProperty(C.prototype, _a,
-    __decorate([
-        dec()
-    ], C.prototype, _a, Object.getOwnPropertyDescriptor(C.prototype, _a)));
+__decorate([
+    dec()
+], C.prototype, _a, null);
 var _a;

tests/baselines/reference/decoratorOnClassMethod6.js

@@ -7,18 +7,15 @@ class C {
 
 //// [decoratorOnClassMethod6.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };
 class C {
     [_a = "method"]() { }
 }
-Object.defineProperty(C.prototype, _a,
-    __decorate([
-        dec
-    ], C.prototype, _a, Object.getOwnPropertyDescriptor(C.prototype, _a)));
+__decorate([
+    dec
+], C.prototype, _a, null);
 var _a;

tests/baselines/reference/decoratorOnClassMethod7.js

@@ -7,18 +7,15 @@ class C {
 
 //// [decoratorOnClassMethod7.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };
 class C {
     [_a = "method"]() { }
 }
-Object.defineProperty(C.prototype, _a,
-    __decorate([
-        dec
-    ], C.prototype, _a, Object.getOwnPropertyDescriptor(C.prototype, _a)));
+__decorate([
+    dec
+], C.prototype, _a, null);
 var _a;

tests/baselines/reference/decoratorOnClassMethod8.js

@@ -7,20 +7,17 @@ class C {
 
 //// [decoratorOnClassMethod8.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     C.prototype.method = function () { };
-    Object.defineProperty(C.prototype, "method",
-        __decorate([
-            dec
-        ], C.prototype, "method", Object.getOwnPropertyDescriptor(C.prototype, "method")));
+    __decorate([
+        dec
+    ], C.prototype, "method", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassMethodParameter1.js

@@ -7,12 +7,10 @@ class C {
 
 //// [decoratorOnClassMethodParameter1.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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 __param = (this && this.__param) || function (paramIndex, decorator) {
     return function (target, key) { decorator(target, key, paramIndex); }
@@ -21,9 +19,8 @@ var C = (function () {
     function C() {
     }
     C.prototype.method = function (p) { };
-    Object.defineProperty(C.prototype, "method",
-        __decorate([
-            __param(0, dec)
-        ], C.prototype, "method", Object.getOwnPropertyDescriptor(C.prototype, "method")));
+    __decorate([
+        __param(0, dec)
+    ], C.prototype, "method", null);
     return C;
 })();

tests/baselines/reference/decoratorOnClassProperty1.js

@@ -7,18 +7,16 @@ class C {
 
 //// [decoratorOnClassProperty1.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     __decorate([
         dec
-    ], C.prototype, "prop");
+    ], C.prototype, "prop", void 0);
     return C;
 })();

tests/baselines/reference/decoratorOnClassProperty10.js

@@ -7,18 +7,16 @@ class C {
 
 //// [decoratorOnClassProperty10.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     __decorate([
         dec()
-    ], C.prototype, "prop");
+    ], C.prototype, "prop", void 0);
     return C;
 })();

tests/baselines/reference/decoratorOnClassProperty11.js

@@ -7,18 +7,16 @@ class C {
 
 //// [decoratorOnClassProperty11.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     __decorate([
         dec
-    ], C.prototype, "prop");
+    ], C.prototype, "prop", void 0);
     return C;
 })();

tests/baselines/reference/decoratorOnClassProperty2.js

@@ -7,18 +7,16 @@ class C {
 
 //// [decoratorOnClassProperty2.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     __decorate([
         dec
-    ], C.prototype, "prop");
+    ], C.prototype, "prop", void 0);
     return C;
 })();

tests/baselines/reference/decoratorOnClassProperty3.js

@@ -7,18 +7,16 @@ class C {
 
 //// [decoratorOnClassProperty3.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     __decorate([
         dec
-    ], C.prototype, "prop");
+    ], C.prototype, "prop", void 0);
     return C;
 })();

tests/baselines/reference/decoratorOnClassProperty6.js

@@ -7,18 +7,16 @@ class C {
 
 //// [decoratorOnClassProperty6.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     __decorate([
         dec
-    ], C.prototype, "prop");
+    ], C.prototype, "prop", void 0);
     return C;
 })();

tests/baselines/reference/decoratorOnClassProperty7.js

@@ -7,18 +7,16 @@ class C {
 
 //// [decoratorOnClassProperty7.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     __decorate([
         dec
-    ], C.prototype, "prop");
+    ], C.prototype, "prop", void 0);
     return C;
 })();

tests/baselines/reference/generatorTypeCheck39.js

@@ -11,12 +11,10 @@ function* g() {
 
 //// [generatorTypeCheck39.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };
 function decorator(x) {
     return y => { };

tests/baselines/reference/generatorTypeCheck59.js

@@ -8,20 +8,17 @@ function* g() {
 
 //// [generatorTypeCheck59.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };
 function* g() {
     class C {
         m() { }
     }
-    Object.defineProperty(C.prototype, "m",
-        __decorate([
-            (yield "")
-        ], C.prototype, "m", Object.getOwnPropertyDescriptor(C.prototype, "m")));
+    __decorate([
+        (yield "")
+    ], C.prototype, "m", null);
     ;
 }

tests/baselines/reference/generatorTypeCheck61.js

@@ -6,12 +6,10 @@ function * g() {
 
 //// [generatorTypeCheck61.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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;
 };
 function* g() {
     let C = class {

tests/baselines/reference/jsxReactTestSuite.symbols

@@ -145,6 +145,7 @@ var x =
 
 <Component { ... x } y
 >Component : Symbol(Component, Decl(jsxReactTestSuite.tsx, 2, 11))
+>x : Symbol(x, Decl(jsxReactTestSuite.tsx, 10, 11), Decl(jsxReactTestSuite.tsx, 35, 3))
 >y : Symbol(unknown)
 
 ={2 } z />;
@@ -167,25 +168,31 @@ var x =
 
 <Component {...x} />;
 >Component : Symbol(Component, Decl(jsxReactTestSuite.tsx, 2, 11))
+>x : Symbol(x, Decl(jsxReactTestSuite.tsx, 10, 11), Decl(jsxReactTestSuite.tsx, 35, 3))
 
 <Component { ...x } y={2} />;
 >Component : Symbol(Component, Decl(jsxReactTestSuite.tsx, 2, 11))
+>x : Symbol(x, Decl(jsxReactTestSuite.tsx, 10, 11), Decl(jsxReactTestSuite.tsx, 35, 3))
 >y : Symbol(unknown)
 
 <Component { ... x } y={2} z />;
 >Component : Symbol(Component, Decl(jsxReactTestSuite.tsx, 2, 11))
+>x : Symbol(x, Decl(jsxReactTestSuite.tsx, 10, 11), Decl(jsxReactTestSuite.tsx, 35, 3))
 >y : Symbol(unknown)
 >z : Symbol(unknown)
 
 <Component x={1} {...y} />;
 >Component : Symbol(Component, Decl(jsxReactTestSuite.tsx, 2, 11))
 >x : Symbol(unknown)
+>y : Symbol(y, Decl(jsxReactTestSuite.tsx, 9, 11))
 
 
 <Component x={1} y="2" {...z} {...z}><Child /></Component>;
 >Component : Symbol(Component, Decl(jsxReactTestSuite.tsx, 2, 11))
 >x : Symbol(unknown)
 >y : Symbol(unknown)
+>z : Symbol(z, Decl(jsxReactTestSuite.tsx, 11, 11))
+>z : Symbol(z, Decl(jsxReactTestSuite.tsx, 11, 11))
 >Child : Symbol(Child, Decl(jsxReactTestSuite.tsx, 5, 11))
 >Component : Symbol(Component, Decl(jsxReactTestSuite.tsx, 2, 11))
 

tests/baselines/reference/missingDecoratorType.js

@@ -24,20 +24,17 @@ class C {
 //// [a.js]
 //// [b.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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() {
     }
     C.prototype.method = function () { };
-    Object.defineProperty(C.prototype, "method",
-        __decorate([
-            dec
-        ], C.prototype, "method", Object.getOwnPropertyDescriptor(C.prototype, "method")));
+    __decorate([
+        dec
+    ], C.prototype, "method", null);
     return C;
 })();

tests/baselines/reference/sourceMapValidationDecorators.js

@@ -56,12 +56,10 @@ class Greeter {
 
 //// [sourceMapValidationDecorators.js]
 var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
-    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") return Reflect.decorate(decorators, target, key, desc);
-    switch (arguments.length) {
-        case 2: return decorators.reduceRight(function(o, d) { return (d && d(o)) || o; }, target);
-        case 3: return decorators.reduceRight(function(o, d) { return (d && d(target, key)), void 0; }, void 0);
-        case 4: return decorators.reduceRight(function(o, d) { return (d && d(target, key, o)) || o; }, 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 __param = (this && this.__param) || function (paramIndex, decorator) {
     return function (target, key) { decorator(target, key, paramIndex); }
@@ -91,31 +89,28 @@ var Greeter = (function () {
         configurable: true
     });
     Greeter.x1 = 10;
-    Object.defineProperty(Greeter.prototype, "greet",
-        __decorate([
-            PropertyDecorator1,
-            PropertyDecorator2(40)
-        ], Greeter.prototype, "greet", Object.getOwnPropertyDescriptor(Greeter.prototype, "greet")));
+    __decorate([
+        PropertyDecorator1,
+        PropertyDecorator2(40)
+    ], Greeter.prototype, "greet", null);
     __decorate([
         PropertyDecorator1,
         PropertyDecorator2(50)
-    ], Greeter.prototype, "x");
-    Object.defineProperty(Greeter.prototype, "fn",
-        __decorate([
-            __param(0, ParameterDecorator1),
-            __param(0, ParameterDecorator2(70))
-        ], Greeter.prototype, "fn", Object.getOwnPropertyDescriptor(Greeter.prototype, "fn")));
-    Object.defineProperty(Greeter.prototype, "greetings",
-        __decorate([
-            PropertyDecorator1,
-            PropertyDecorator2(80),
-            __param(0, ParameterDecorator1),
-            __param(0, ParameterDecorator2(90))
-        ], Greeter.prototype, "greetings", Object.getOwnPropertyDescriptor(Greeter.prototype, "greetings")));
+    ], Greeter.prototype, "x", void 0);
+    __decorate([
+        __param(0, ParameterDecorator1),
+        __param(0, ParameterDecorator2(70))
+    ], Greeter.prototype, "fn", null);
+    __decorate([
+        PropertyDecorator1,
+        PropertyDecorator2(80),
+        __param(0, ParameterDecorator1),
+        __param(0, ParameterDecorator2(90))
+    ], Greeter.prototype, "greetings", null);
     __decorate([
         PropertyDecorator1,
         PropertyDecorator2(60)
-    ], Greeter, "x1");
+    ], Greeter, "x1", void 0);
     Greeter = __decorate([
         ClassDecorator1,
         ClassDecorator2(10),

tests/baselines/reference/sourceMapValidationDecorators.js.map

@@ -1,2 +1,2 @@
 //// [sourceMapValidationDecorators.js.map]
-{"version":3,"file":"sourceMapValidationDecorators.js","sourceRoot":"","sources":["sourceMapValidationDecorators.ts"],"names":["Greeter","Greeter.constructor","Greeter.greet","Greeter.fn","Greeter.greetings"],"mappings":";;;;;;;;;;;AAOA;IAGIA,iBAGSA,QAAgBA;QAEvBC,WAEcA;aAFdA,WAEcA,CAFdA,sBAEcA,CAFdA,IAEcA;YAFdA,0BAEcA;;QAJPA,aAAQA,GAARA,QAAQA,CAAQA;IAKzBA,CAACA;IAIDD,uBAAKA,GAFLA;QAGIE,MAAMA,CAACA,MAAMA,GAAGA,IAAIA,CAACA,QAAQA,GAAGA,OAAOA,CAACA;IAC5CA,CAACA;IAUOF,oBAAEA,GAAVA,UAGEA,CAASA;QACPG,MAAMA,CAACA,IAAIA,CAACA,QAAQA,CAACA;IACzBA,CAACA;IAEDH,sBAEIA,8BAASA;aAFbA;YAGII,MAAMA,CAACA,IAAIA,CAACA,QAAQA,CAACA;QACzBA,CAACA;aAEDJ,UAGEA,SAAiBA;YACfI,IAAIA,CAACA,QAAQA,GAAGA,SAASA,CAACA;QAC9BA,CAACA;;;OAPAJ;IAbcA,UAAEA,GAAWA,EAAEA,CAACA;IAZ/BA,sBAEAA,0BAAKA;;YAFJA,kBAAkBA;YAClBA,kBAAkBA,CAACA,EAAEA,CAACA;WACvBA,0BAAKA,kCAALA,0BAAKA,IAEJA;IAEDA;QAACA,kBAAkBA;QAClBA,kBAAkBA,CAACA,EAAEA,CAACA;OACfA,sBAACA,EAASA;IAMlBA,sBAAQA,uBAAEA;;YACRA,WAACA,mBAAmBA,CAAAA;YACpBA,WAACA,mBAAmBA,CAACA,EAAEA,CAACA,CAAAA;WAFlBA,uBAAEA,kCAAFA,uBAAEA,IAKTA;IAEDA,sBAEIA,8BAASA;;YAFZA,kBAAkBA;YAClBA,kBAAkBA,CAACA,EAAEA,CAACA;YAMrBA,WAACA,mBAAmBA,CAAAA;YACpBA,WAACA,mBAAmBA,CAACA,EAAEA,CAACA,CAAAA;WANtBA,8BAASA,kCAATA,8BAASA,IAEZA;IAfDA;QAACA,kBAAkBA;QAClBA,kBAAkBA,CAACA,EAAEA,CAACA;OACRA,aAAEA,EAAcA;IAzBnCA;QAACA,eAAeA;QACfA,eAAeA,CAACA,EAAEA,CAACA;QAGdA,WAACA,mBAAmBA,CAAAA;QACpBA,WAACA,mBAAmBA,CAACA,EAAEA,CAACA,CAAAA;QAGxBA,WAACA,mBAAmBA,CAAAA;QACpBA,WAACA,mBAAmBA,CAACA,EAAEA,CAACA,CAAAA;gBAqC7BA;IAADA,cAACA;AAADA,CAACA,AA9CD,IA8CC"}
+{"version":3,"file":"sourceMapValidationDecorators.js","sourceRoot":"","sources":["sourceMapValidationDecorators.ts"],"names":["Greeter","Greeter.constructor","Greeter.greet","Greeter.fn","Greeter.greetings"],"mappings":";;;;;;;;;AAOA;IAGIA,iBAGSA,QAAgBA;QAEvBC,WAEcA;aAFdA,WAEcA,CAFdA,sBAEcA,CAFdA,IAEcA;YAFdA,0BAEcA;;QAJPA,aAAQA,GAARA,QAAQA,CAAQA;IAKzBA,CAACA;IAIDD,uBAAKA,GAFLA;QAGIE,MAAMA,CAACA,MAAMA,GAAGA,IAAIA,CAACA,QAAQA,GAAGA,OAAOA,CAACA;IAC5CA,CAACA;IAUOF,oBAAEA,GAAVA,UAGEA,CAASA;QACPG,MAAMA,CAACA,IAAIA,CAACA,QAAQA,CAACA;IACzBA,CAACA;IAEDH,sBAEIA,8BAASA;aAFbA;YAGII,MAAMA,CAACA,IAAIA,CAACA,QAAQA,CAACA;QACzBA,CAACA;aAEDJ,UAGEA,SAAiBA;YACfI,IAAIA,CAACA,QAAQA,GAAGA,SAASA,CAACA;QAC9BA,CAACA;;;OAPAJ;IAbcA,UAAEA,GAAWA,EAAEA,CAACA;IAZ/BA;QAACA,kBAAkBA;QAClBA,kBAAkBA,CAACA,EAAEA,CAACA;OACvBA,0BAAKA,QAEJA;IAEDA;QAACA,kBAAkBA;QAClBA,kBAAkBA,CAACA,EAAEA,CAACA;OACfA,sBAACA,UAASA;IAMlBA;QACEA,WAACA,mBAAmBA,CAAAA;QACpBA,WAACA,mBAAmBA,CAACA,EAAEA,CAACA,CAAAA;OAFlBA,uBAAEA,QAKTA;IAEDA;QAACA,kBAAkBA;QAClBA,kBAAkBA,CAACA,EAAEA,CAACA;QAMrBA,WAACA,mBAAmBA,CAAAA;QACpBA,WAACA,mBAAmBA,CAACA,EAAEA,CAACA,CAAAA;OANtBA,8BAASA,QAEZA;IAfDA;QAACA,kBAAkBA;QAClBA,kBAAkBA,CAACA,EAAEA,CAACA;OACRA,aAAEA,UAAcA;IAzBnCA;QAACA,eAAeA;QACfA,eAAeA,CAACA,EAAEA,CAACA;QAGdA,WAACA,mBAAmBA,CAAAA;QACpBA,WAACA,mBAAmBA,CAACA,EAAEA,CAACA,CAAAA;QAGxBA,WAACA,mBAAmBA,CAAAA;QACpBA,WAACA,mBAAmBA,CAACA,EAAEA,CAACA,CAAAA;gBAqC7BA;IAADA,cAACA;AAADA,CAACA,AA9CD,IA8CC"}

tests/baselines/reference/tsxAttributeResolution8.symbols

@@ -20,4 +20,5 @@ var x: any;
 // Should be OK
 <test1 {...x} />
 >test1 : Symbol(JSX.IntrinsicElements.test1, Decl(tsxAttributeResolution8.tsx, 2, 30))
+>x : Symbol(x, Decl(tsxAttributeResolution8.tsx, 7, 3))
 

tests/baselines/reference/tsxEmit2.symbols

@@ -21,12 +21,14 @@ var p1, p2, p3;
 var spreads1 = <div {...p1}>{p2}</div>;
 >spreads1 : Symbol(spreads1, Decl(tsxEmit2.tsx, 8, 3))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxEmit2.tsx, 1, 22))
+>p1 : Symbol(p1, Decl(tsxEmit2.tsx, 7, 3))
 >p2 : Symbol(p2, Decl(tsxEmit2.tsx, 7, 7))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxEmit2.tsx, 1, 22))
 
 var spreads2 = <div {...p1}>{p2}</div>;
 >spreads2 : Symbol(spreads2, Decl(tsxEmit2.tsx, 9, 3))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxEmit2.tsx, 1, 22))
+>p1 : Symbol(p1, Decl(tsxEmit2.tsx, 7, 3))
 >p2 : Symbol(p2, Decl(tsxEmit2.tsx, 7, 7))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxEmit2.tsx, 1, 22))
 
@@ -35,12 +37,14 @@ var spreads3 = <div x={p3} {...p1}>{p2}</div>;
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxEmit2.tsx, 1, 22))
 >x : Symbol(unknown)
 >p3 : Symbol(p3, Decl(tsxEmit2.tsx, 7, 11))
+>p1 : Symbol(p1, Decl(tsxEmit2.tsx, 7, 3))
 >p2 : Symbol(p2, Decl(tsxEmit2.tsx, 7, 7))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxEmit2.tsx, 1, 22))
 
 var spreads4 = <div {...p1} x={p3} >{p2}</div>;
 >spreads4 : Symbol(spreads4, Decl(tsxEmit2.tsx, 11, 3))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxEmit2.tsx, 1, 22))
+>p1 : Symbol(p1, Decl(tsxEmit2.tsx, 7, 3))
 >x : Symbol(unknown)
 >p3 : Symbol(p3, Decl(tsxEmit2.tsx, 7, 11))
 >p2 : Symbol(p2, Decl(tsxEmit2.tsx, 7, 7))
@@ -51,6 +55,7 @@ var spreads5 = <div x={p2} {...p1} y={p3}>{p2}</div>;
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxEmit2.tsx, 1, 22))
 >x : Symbol(unknown)
 >p2 : Symbol(p2, Decl(tsxEmit2.tsx, 7, 7))
+>p1 : Symbol(p1, Decl(tsxEmit2.tsx, 7, 3))
 >y : Symbol(unknown)
 >p3 : Symbol(p3, Decl(tsxEmit2.tsx, 7, 11))
 >p2 : Symbol(p2, Decl(tsxEmit2.tsx, 7, 7))

tests/baselines/reference/tsxExternalModuleEmit2.symbols

@@ -26,6 +26,7 @@ declare var Foo, React;
 // Should see mod_1['default'] in emit here
 <Foo {...Main}></Foo>;
 >Foo : Symbol(Foo, Decl(app.tsx, 1, 11))
+>Main : Symbol(Main, Decl(app.tsx, 0, 6))
 >Foo : Symbol(Foo, Decl(app.tsx, 1, 11))
 
 

tests/baselines/reference/tsxReactEmit2.symbols

@@ -23,12 +23,14 @@ var p1, p2, p3;
 var spreads1 = <div {...p1}>{p2}</div>;
 >spreads1 : Symbol(spreads1, Decl(tsxReactEmit2.tsx, 9, 3))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxReactEmit2.tsx, 1, 22))
+>p1 : Symbol(p1, Decl(tsxReactEmit2.tsx, 8, 3))
 >p2 : Symbol(p2, Decl(tsxReactEmit2.tsx, 8, 7))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxReactEmit2.tsx, 1, 22))
 
 var spreads2 = <div {...p1}>{p2}</div>;
 >spreads2 : Symbol(spreads2, Decl(tsxReactEmit2.tsx, 10, 3))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxReactEmit2.tsx, 1, 22))
+>p1 : Symbol(p1, Decl(tsxReactEmit2.tsx, 8, 3))
 >p2 : Symbol(p2, Decl(tsxReactEmit2.tsx, 8, 7))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxReactEmit2.tsx, 1, 22))
 
@@ -37,12 +39,14 @@ var spreads3 = <div x={p3} {...p1}>{p2}</div>;
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxReactEmit2.tsx, 1, 22))
 >x : Symbol(unknown)
 >p3 : Symbol(p3, Decl(tsxReactEmit2.tsx, 8, 11))
+>p1 : Symbol(p1, Decl(tsxReactEmit2.tsx, 8, 3))
 >p2 : Symbol(p2, Decl(tsxReactEmit2.tsx, 8, 7))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxReactEmit2.tsx, 1, 22))
 
 var spreads4 = <div {...p1} x={p3} >{p2}</div>;
 >spreads4 : Symbol(spreads4, Decl(tsxReactEmit2.tsx, 12, 3))
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxReactEmit2.tsx, 1, 22))
+>p1 : Symbol(p1, Decl(tsxReactEmit2.tsx, 8, 3))
 >x : Symbol(unknown)
 >p3 : Symbol(p3, Decl(tsxReactEmit2.tsx, 8, 11))
 >p2 : Symbol(p2, Decl(tsxReactEmit2.tsx, 8, 7))
@@ -53,6 +57,7 @@ var spreads5 = <div x={p2} {...p1} y={p3}>{p2}</div>;
 >div : Symbol(JSX.IntrinsicElements, Decl(tsxReactEmit2.tsx, 1, 22))
 >x : Symbol(unknown)
 >p2 : Symbol(p2, Decl(tsxReactEmit2.tsx, 8, 7))
+>p1 : Symbol(p1, Decl(tsxReactEmit2.tsx, 8, 3))
 >y : Symbol(unknown)
 >p3 : Symbol(p3, Decl(tsxReactEmit2.tsx, 8, 11))
 >p2 : Symbol(p2, Decl(tsxReactEmit2.tsx, 8, 7))

tests/baselines/reference/tsxReactEmit5.symbols

@@ -31,5 +31,6 @@ var spread1 = <div x='' {...foo} y='' />;
 >spread1 : Symbol(spread1, Decl(react-consumer.tsx, 4, 3))
 >div : Symbol(JSX.IntrinsicElements, Decl(file.tsx, 2, 22))
 >x : Symbol(unknown)
+>foo : Symbol(foo, Decl(react-consumer.tsx, 3, 3))
 >y : Symbol(unknown)
 

tests/baselines/reference/tsxReactEmit6.symbols

@@ -34,6 +34,7 @@ namespace M {
 >spread1 : Symbol(spread1, Decl(react-consumer.tsx, 8, 4))
 >div : Symbol(JSX.IntrinsicElements, Decl(file.tsx, 2, 22))
 >x : Symbol(unknown)
+>foo : Symbol(foo, Decl(react-consumer.tsx, 7, 4))
 >y : Symbol(unknown)
 }
 

tests/cases/fourslash/jsxSpreadReference.ts

@@ -0,0 +1,25 @@
+/// <reference path='fourslash.ts' />
+
+//@Filename: file.tsx
+//// declare module JSX {
+////     interface Element { }
+////     interface IntrinsicElements {
+////     }
+////     interface ElementAttributesProperty { props }
+//// }
+//// class MyClass {
+////   props: {
+////     name?: string;
+////     size?: number;
+////   }
+//// }
+////
+//// var [|/*dst*/nn|]: {name?: string; size?: number};
+//// var x = <MyClass {...[|n/*src*/n|]}></MyClass>;
+
+goTo.marker('src');
+goTo.definition();
+verify.caretAtMarker('dst');
+
+goTo.marker('src');
+verify.renameLocations(/*findInStrings*/ false, /*findInComments*/ false);