use const instead of let for new class iife assignments (#36907)

Author: weswigham

src/compiler/transformers/ts.ts

@@ -673,7 +673,7 @@ namespace ts {
                             /*type*/ undefined,
                             iife
                         )
-                    ], languageVersion > ScriptTarget.ES5 ? NodeFlags.Let : undefined)
+                    ], languageVersion > ScriptTarget.ES5 ? NodeFlags.Const : undefined)
                 );
 
                 setOriginalNode(varStatement, node);

tests/baselines/reference/awaitAndYieldInProperty.js

@@ -20,7 +20,7 @@ async function* test(x: Promise<string>) {
 //// [awaitAndYieldInProperty.js]
 async function* test(x) {
     var _a, _b, _c, _d, _e;
-    let C = /** @class */ (() => {
+    const C = /** @class */ (() => {
         var _e, _f, _g, _h;
         class C {
             constructor() {

tests/baselines/reference/classDeclarationCheckUsedBeforeDefinitionInItself.js

@@ -4,7 +4,7 @@ class C3 {
 }
 
 //// [classDeclarationCheckUsedBeforeDefinitionInItself.js]
-let C3 = /** @class */ (() => {
+const C3 = /** @class */ (() => {
     class C3 {
     }
     C3.intance = new C3(); // ok

tests/baselines/reference/computedPropertyNames12_ES6.js

@@ -20,7 +20,7 @@ class C {
 var s;
 var n;
 var a;
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     var _a, _b, _c;
     class C {
         constructor() {

tests/baselines/reference/computedPropertyNamesWithStaticProperty.js

@@ -11,7 +11,7 @@ class C {
 }
 
 //// [computedPropertyNamesWithStaticProperty.js]
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     class C {
         get [C.staticProp]() {
             return "hello";

tests/baselines/reference/decoratedClassExportsCommonJS1.js

@@ -15,7 +15,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     return c > 3 && r && Object.defineProperty(target, key, r), r;
 };
 Object.defineProperty(exports, "__esModule", { value: true });
-let Testing123 = /** @class */ (() => {
+const Testing123 = /** @class */ (() => {
     var Testing123_1;
     let Testing123 = Testing123_1 = class Testing123 {
     };

tests/baselines/reference/decoratedClassExportsCommonJS2.js

@@ -13,7 +13,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     return c > 3 && r && Object.defineProperty(target, key, r), r;
 };
 Object.defineProperty(exports, "__esModule", { value: true });
-let Testing123 = /** @class */ (() => {
+const Testing123 = /** @class */ (() => {
     var Testing123_1;
     let Testing123 = Testing123_1 = class Testing123 {
     };

tests/baselines/reference/decoratedClassFromExternalModule.js

@@ -17,7 +17,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     return c > 3 && r && Object.defineProperty(target, key, r), r;
 };
 function decorate(target) { }
-let Decorated = /** @class */ (() => {
+const Decorated = /** @class */ (() => {
     let Decorated = class Decorated {
     };
     Decorated = __decorate([

tests/baselines/reference/decoratedDefaultExportsGetExportedAmd.js

@@ -24,7 +24,7 @@ define(["require", "exports"], function (require, exports) {
     "use strict";
     Object.defineProperty(exports, "__esModule", { value: true });
     var decorator;
-    let Foo = /** @class */ (() => {
+    const Foo = /** @class */ (() => {
         let Foo = class Foo {
         };
         Foo = __decorate([
@@ -45,7 +45,7 @@ define(["require", "exports"], function (require, exports) {
     "use strict";
     Object.defineProperty(exports, "__esModule", { value: true });
     var decorator;
-    let default_1 = /** @class */ (() => {
+    const default_1 = /** @class */ (() => {
         let default_1 = class {
         };
         default_1 = __decorate([

tests/baselines/reference/decoratedDefaultExportsGetExportedCommonjs.js

@@ -23,7 +23,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
 };
 Object.defineProperty(exports, "__esModule", { value: true });
 var decorator;
-let Foo = /** @class */ (() => {
+const Foo = /** @class */ (() => {
     let Foo = class Foo {
     };
     Foo = __decorate([
@@ -42,7 +42,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
 };
 Object.defineProperty(exports, "__esModule", { value: true });
 var decorator;
-let default_1 = /** @class */ (() => {
+const default_1 = /** @class */ (() => {
     let default_1 = class {
     };
     default_1 = __decorate([

tests/baselines/reference/decoratedDefaultExportsGetExportedUmd.js

@@ -32,7 +32,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     "use strict";
     Object.defineProperty(exports, "__esModule", { value: true });
     var decorator;
-    let Foo = /** @class */ (() => {
+    const Foo = /** @class */ (() => {
         let Foo = class Foo {
         };
         Foo = __decorate([
@@ -61,7 +61,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     "use strict";
     Object.defineProperty(exports, "__esModule", { value: true });
     var decorator;
-    let default_1 = /** @class */ (() => {
+    const default_1 = /** @class */ (() => {
         let default_1 = class {
         };
         default_1 = __decorate([

tests/baselines/reference/decoratorMetadataPromise.js

@@ -30,7 +30,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
         step((generator = generator.apply(thisArg, _arguments || [])).next());
     });
 };
-let A = /** @class */ (() => {
+const A = /** @class */ (() => {
     class A {
         foo() {
             return __awaiter(this, void 0, void 0, function* () { });

tests/baselines/reference/decoratorOnClass1.es6.js

@@ -14,7 +14,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     let C = class C {
     };
     C = __decorate([

tests/baselines/reference/decoratorOnClass2.es6.js

@@ -14,7 +14,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     let C = class C {
     };
     C = __decorate([

tests/baselines/reference/decoratorOnClass3.es6.js

@@ -14,7 +14,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     let C = class C {
     };
     C = __decorate([

tests/baselines/reference/decoratorOnClass4.es6.js

@@ -12,7 +12,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let default_1 = /** @class */ (() => {
+const default_1 = /** @class */ (() => {
     let default_1 = class {
     };
     default_1 = __decorate([

tests/baselines/reference/decoratorOnClass5.es6.js

@@ -16,7 +16,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     var C_1;
     let C = C_1 = class C {
         static x() { return C_1.y; }

tests/baselines/reference/decoratorOnClass6.es6.js

@@ -16,7 +16,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     var C_1;
     let C = C_1 = class C {
         static x() { return C_1.y; }

tests/baselines/reference/decoratorOnClass7.es6.js

@@ -16,7 +16,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     var C_1;
     let C = C_1 = class C {
         static x() { return C_1.y; }

tests/baselines/reference/decoratorOnClass8.es6.js

@@ -13,7 +13,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let default_1 = /** @class */ (() => {
+const default_1 = /** @class */ (() => {
     let default_1 = class default_1 {
     };
     default_1.y = 1;

tests/baselines/reference/decoratorOnClassAccessor1.es6.js

@@ -12,7 +12,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let default_1 = /** @class */ (() => {
+const default_1 = /** @class */ (() => {
     class default_1 {
         get accessor() { return 1; }
     }

tests/baselines/reference/decoratorOnClassMethod1.es6.js

@@ -12,7 +12,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let default_1 = /** @class */ (() => {
+const default_1 = /** @class */ (() => {
     class default_1 {
         method() { }
     }

tests/baselines/reference/decoratorOnClassMethod13.js

@@ -13,7 +13,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     class C {
         ["1"]() { }
         ["b"]() { }

tests/baselines/reference/decoratorOnClassMethod4.js

@@ -12,7 +12,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     class C {
         ["method"]() { }
     }

tests/baselines/reference/decoratorOnClassMethod5.js

@@ -12,7 +12,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     class C {
         ["method"]() { }
     }

tests/baselines/reference/decoratorOnClassMethod6.js

@@ -12,7 +12,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     class C {
         ["method"]() { }
     }

tests/baselines/reference/decoratorOnClassMethod7.js

@@ -12,7 +12,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     class C {
         ["method"]() { }
     }

tests/baselines/reference/decoratorOnClassMethodParameter1.es6.js

@@ -15,7 +15,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
 var __param = (this && this.__param) || function (paramIndex, decorator) {
     return function (target, key) { decorator(target, key, paramIndex); }
 };
-let default_1 = /** @class */ (() => {
+const default_1 = /** @class */ (() => {
     class default_1 {
         method(p) { }
     }

tests/baselines/reference/decoratorOnClassProperty1.es6.js

@@ -12,7 +12,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let default_1 = /** @class */ (() => {
+const default_1 = /** @class */ (() => {
     class default_1 {
     }
     __decorate([

tests/baselines/reference/decoratorsOnComputedProperties.js

@@ -204,7 +204,7 @@ function foo() { return ++i + ""; }
 const fieldNameA = "fieldName1";
 const fieldNameB = "fieldName2";
 const fieldNameC = "fieldName3";
-let A = /** @class */ (() => {
+const A = /** @class */ (() => {
     var _a, _b, _c, _d;
     class A {
         constructor() {
@@ -259,7 +259,7 @@ void (_a = class B {
     _g = fieldNameB,
     _h = fieldNameC,
     _a);
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     var _a, _b, _c, _d;
     class C {
         constructor() {
@@ -309,7 +309,7 @@ void class D {
     }
     [(foo(), _j = foo(), _k = foo(), _l = fieldNameB, _m = fieldNameC, "some" + "method")]() { }
 };
-let E = /** @class */ (() => {
+const E = /** @class */ (() => {
     var _a, _b, _c, _d;
     class E {
         constructor() {
@@ -363,7 +363,7 @@ void (_b = class F {
     _q = fieldNameB,
     _r = fieldNameC,
     _b);
-let G = /** @class */ (() => {
+const G = /** @class */ (() => {
     var _a, _b, _c, _d;
     class G {
         constructor() {
@@ -418,7 +418,7 @@ void (_c = class H {
     },
     _v = fieldNameC,
     _c);
-let I = /** @class */ (() => {
+const I = /** @class */ (() => {
     var _a, _b, _c, _d, _e;
     class I {
         constructor() {

tests/baselines/reference/emitClassDeclarationWithLiteralPropertyNameInES6.js

@@ -15,7 +15,7 @@ class B {
 }
 
 //// [emitClassDeclarationWithLiteralPropertyNameInES6.js]
-let B = /** @class */ (() => {
+const B = /** @class */ (() => {
     class B {
         constructor() {
             this["hello"] = 10;

tests/baselines/reference/emitClassDeclarationWithStaticPropertyAssignmentInES6.js

@@ -10,13 +10,13 @@ class D {
 
 
 //// [emitClassDeclarationWithStaticPropertyAssignmentInES6.js]
-let C = /** @class */ (() => {
+const C = /** @class */ (() => {
     class C {
     }
     C.z = "Foo";
     return C;
 })();
-let D = /** @class */ (() => {
+const D = /** @class */ (() => {
     class D {
         constructor() {
             this.x = 20000;

tests/baselines/reference/emitHelpersWithLocalCollisions(module=amd).js

@@ -17,7 +17,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
 define(["require", "exports"], function (require, exports) {
     "use strict";
     Object.defineProperty(exports, "__esModule", { value: true });
-    let A = /** @class */ (() => {
+    const A = /** @class */ (() => {
         let A = class A {
         };
         A = __decorate([

tests/baselines/reference/emitHelpersWithLocalCollisions(module=commonjs).js

@@ -16,7 +16,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     return c > 3 && r && Object.defineProperty(target, key, r), r;
 };
 Object.defineProperty(exports, "__esModule", { value: true });
-let A = /** @class */ (() => {
+const A = /** @class */ (() => {
     let A = class A {
     };
     A = __decorate([

tests/baselines/reference/emitHelpersWithLocalCollisions(module=es2020).js

@@ -14,7 +14,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let A = /** @class */ (() => {
+const A = /** @class */ (() => {
     let A = class A {
     };
     A = __decorate([

tests/baselines/reference/emitHelpersWithLocalCollisions(module=es6).js

@@ -14,7 +14,7 @@ var __decorate = (this && this.__decorate) || function (decorators, target, key,
     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;
 };
-let A = /** @class */ (() => {
+const A = /** @class */ (() => {
     let A = class A {
     };
     A = __decorate([