Fix tslib resolutions (#58451)

Co-authored-by: Sheetal Nandi <shkamat@microsoft.com>

src/compiler/checker.ts

@@ -32194,12 +32194,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         const errorMessage = isClassic
             ? Diagnostics.Cannot_find_module_0_Did_you_mean_to_set_the_moduleResolution_option_to_nodenext_or_to_add_aliases_to_the_paths_option
             : Diagnostics.Cannot_find_module_0_or_its_corresponding_type_declarations;
-        // Synthesized JSX import is either first or after tslib
-        const jsxImportIndex = compilerOptions.importHelpers ? 1 : 0;
-        const specifier = file?.imports[jsxImportIndex];
-        if (specifier) {
-            Debug.assert(nodeIsSynthesized(specifier) && specifier.text === runtimeImportSpecifier, `Expected sourceFile.imports[${jsxImportIndex}] to be the synthesized JSX runtime import`);
-        }
+        const specifier = getJSXRuntimeImportSpecifier(file, runtimeImportSpecifier);
         const mod = resolveExternalModule(specifier || location!, runtimeImportSpecifier, errorMessage, location!);
         const result = mod && mod !== unknownSymbol ? getMergedSymbol(resolveSymbol(mod)) : undefined;
         if (links) {
@@ -49193,9 +49188,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         }
     }
 
-    function resolveHelpersModule(node: SourceFile, errorNode: Node) {
+    function resolveHelpersModule(file: SourceFile, errorNode: Node) {
         if (!externalHelpersModule) {
-            externalHelpersModule = resolveExternalModule(node, externalHelpersModuleNameText, Diagnostics.This_syntax_requires_an_imported_helper_but_module_0_cannot_be_found, errorNode) || unknownSymbol;
+            externalHelpersModule = resolveExternalModule(getImportHelpersImportSpecifier(file), externalHelpersModuleNameText, Diagnostics.This_syntax_requires_an_imported_helper_but_module_0_cannot_be_found, errorNode) || unknownSymbol;
         }
         return externalHelpersModule;
     }
@@ -51145,6 +51140,23 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             blockScopeKind === NodeFlags.Using ||
             blockScopeKind === NodeFlags.AwaitUsing;
     }
+
+    function getJSXRuntimeImportSpecifier(file: SourceFile | undefined, specifierText: string) {
+        // Synthesized JSX import is either first or after tslib
+        const jsxImportIndex = compilerOptions.importHelpers ? 1 : 0;
+        const specifier = file?.imports[jsxImportIndex];
+        if (specifier) {
+            Debug.assert(nodeIsSynthesized(specifier) && specifier.text === specifierText, `Expected sourceFile.imports[${jsxImportIndex}] to be the synthesized JSX runtime import`);
+        }
+        return specifier;
+    }
+
+    function getImportHelpersImportSpecifier(file: SourceFile) {
+        Debug.assert(compilerOptions.importHelpers, "Expected importHelpers to be enabled");
+        const specifier = file.imports[0];
+        Debug.assert(specifier && nodeIsSynthesized(specifier) && specifier.text === "tslib", `Expected sourceFile.imports[0] to be the synthesized tslib import`);
+        return specifier;
+    }
 }
 
 function isNotAccessor(declaration: Declaration): boolean {

src/compiler/program.ts

@@ -3419,7 +3419,7 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
 
     function createSyntheticImport(text: string, file: SourceFile) {
         const externalHelpersModuleReference = factory.createStringLiteral(text);
-        const importDecl = factory.createImportDeclaration(/*modifiers*/ undefined, /*importClause*/ undefined, externalHelpersModuleReference, /*attributes*/ undefined);
+        const importDecl = factory.createImportDeclaration(/*modifiers*/ undefined, /*importClause*/ undefined, externalHelpersModuleReference);
         addInternalEmitFlags(importDecl, InternalEmitFlags.NeverApplyImportHelper);
         setParent(externalHelpersModuleReference, importDecl);
         setParent(importDecl, file);
@@ -3444,11 +3444,11 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
         let ambientModules: string[] | undefined;
 
         // If we are importing helpers, we need to add a synthetic reference to resolve the
-        // helpers library.
-        if (
-            (getIsolatedModules(options) || isExternalModuleFile)
-            && !file.isDeclarationFile
-        ) {
+        // helpers library. (A JavaScript file without `externalModuleIndicator` set might be
+        // a CommonJS module; `commonJsModuleIndicator` doesn't get set until the binder has
+        // run. We synthesize a helpers import for it just in case; it will never be used if
+        // the binder doesn't find and set a `commonJsModuleIndicator`.)
+        if (isJavaScriptFile || (!file.isDeclarationFile && (getIsolatedModules(options) || isExternalModule(file)))) {
             if (options.importHelpers) {
                 // synthesize 'import "tslib"' declaration
                 imports = [createSyntheticImport(externalHelpersModuleNameText, file)];

tests/baselines/reference/importHelpersBundler.js

@@ -0,0 +1,51 @@
+//// [tests/cases/compiler/importHelpersBundler.ts] ////
+
+//// [package.json]
+{
+  "name": "tslib",
+  "main": "tslib.js",
+  "module": "tslib.es6.js",
+  "jsnext:main": "tslib.es6.js",
+  "typings": "tslib.d.ts",
+  "exports": {
+      ".": {
+          "module": {
+              "types": "./modules/index.d.ts",
+              "default": "./tslib.es6.mjs"
+          },
+          "import": {
+              "node": "./modules/index.js",
+              "default": {
+                  "types": "./modules/index.d.ts",
+                  "default": "./tslib.es6.mjs"
+              }
+          },
+          "default": "./tslib.js"
+      },
+      "./*": "./*",
+      "./": "./"
+  }
+}
+
+//// [tslib.d.ts]
+export {};
+
+//// [package.json]
+{ "type": "module" }
+
+//// [index.d.ts]
+export declare var __rest: any;
+
+//// [main.ts]
+export function foo(args: any) {
+  const { bar, ...extraArgs } = args;
+  return extraArgs;
+}
+
+
+//// [main.js]
+import { __rest } from "tslib";
+export function foo(args) {
+    const { bar } = args, extraArgs = __rest(args, ["bar"]);
+    return extraArgs;
+}

tests/baselines/reference/importHelpersBundler.symbols

@@ -0,0 +1,24 @@
+//// [tests/cases/compiler/importHelpersBundler.ts] ////
+
+=== /node_modules/tslib/tslib.d.ts ===
+
+export {};
+
+=== /node_modules/tslib/modules/index.d.ts ===
+export declare var __rest: any;
+>__rest : Symbol(__rest, Decl(index.d.ts, 0, 18))
+
+=== /main.ts ===
+export function foo(args: any) {
+>foo : Symbol(foo, Decl(main.ts, 0, 0))
+>args : Symbol(args, Decl(main.ts, 0, 20))
+
+  const { bar, ...extraArgs } = args;
+>bar : Symbol(bar, Decl(main.ts, 1, 9))
+>extraArgs : Symbol(extraArgs, Decl(main.ts, 1, 14))
+>args : Symbol(args, Decl(main.ts, 0, 20))
+
+  return extraArgs;
+>extraArgs : Symbol(extraArgs, Decl(main.ts, 1, 14))
+}
+

tests/baselines/reference/importHelpersBundler.types

@@ -0,0 +1,27 @@
+//// [tests/cases/compiler/importHelpersBundler.ts] ////
+
+=== /node_modules/tslib/tslib.d.ts ===
+
+export {};
+
+=== /node_modules/tslib/modules/index.d.ts ===
+export declare var __rest: any;
+>__rest : any
+
+=== /main.ts ===
+export function foo(args: any) {
+>foo : (args: any) => any
+>    : ^    ^^   ^^^^^^^^
+>args : any
+
+  const { bar, ...extraArgs } = args;
+>bar : any
+>    : ^^^
+>extraArgs : any
+>          : ^^^
+>args : any
+
+  return extraArgs;
+>extraArgs : any
+}
+

tests/baselines/reference/importHelpersCommonJSJavaScript(verbatimmodulesyntax=false).js

@@ -0,0 +1,61 @@
+//// [tests/cases/compiler/importHelpersCommonJSJavaScript.ts] ////
+
+//// [package.json]
+{
+  "name": "tslib",
+  "main": "tslib.js",
+  "module": "tslib.es6.js",
+  "jsnext:main": "tslib.es6.js",
+  "typings": "tslib.d.ts",
+  "exports": {
+      ".": {
+          "module": {
+              "types": "./modules/index.d.ts",
+              "default": "./tslib.es6.mjs"
+          },
+          "import": {
+              "node": "./modules/index.js",
+              "default": {
+                  "types": "./modules/index.d.ts",
+                  "default": "./tslib.es6.mjs"
+              }
+          },
+          "default": "./tslib.js"
+      },
+      "./*": "./*",
+      "./": "./"
+  }
+}
+
+//// [tslib.d.ts]
+export declare var __extends: any;
+
+//// [package.json]
+{ "type": "module" }
+
+//// [index.d.ts]
+export {};
+
+//// [index.js]
+class Foo {}
+
+class Bar extends Foo {}
+
+module.exports = Bar;
+
+
+//// [index.js]
+var tslib_1 = require("tslib");
+var Foo = /** @class */ (function () {
+    function Foo() {
+    }
+    return Foo;
+}());
+var Bar = /** @class */ (function (_super) {
+    tslib_1.__extends(Bar, _super);
+    function Bar() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return Bar;
+}(Foo));
+module.exports = Bar;

tests/baselines/reference/importHelpersCommonJSJavaScript(verbatimmodulesyntax=false).symbols

@@ -0,0 +1,24 @@
+//// [tests/cases/compiler/importHelpersCommonJSJavaScript.ts] ////
+
+=== /node_modules/tslib/tslib.d.ts ===
+export declare var __extends: any;
+>__extends : Symbol(__extends, Decl(tslib.d.ts, --, --))
+
+=== /node_modules/tslib/modules/index.d.ts ===
+
+export {};
+
+=== /index.js ===
+class Foo {}
+>Foo : Symbol(Foo, Decl(index.js, 0, 0))
+
+class Bar extends Foo {}
+>Bar : Symbol(Bar, Decl(index.js, 0, 12))
+>Foo : Symbol(Foo, Decl(index.js, 0, 0))
+
+module.exports = Bar;
+>module.exports : Symbol(module.exports, Decl(index.js, 0, 0))
+>module : Symbol(export=, Decl(index.js, 2, 24))
+>exports : Symbol(export=, Decl(index.js, 2, 24))
+>Bar : Symbol(Bar, Decl(index.js, 0, 12))
+

tests/baselines/reference/importHelpersCommonJSJavaScript(verbatimmodulesyntax=false).types

@@ -0,0 +1,33 @@
+//// [tests/cases/compiler/importHelpersCommonJSJavaScript.ts] ////
+
+=== /node_modules/tslib/tslib.d.ts ===
+export declare var __extends: any;
+>__extends : any
+
+=== /node_modules/tslib/modules/index.d.ts ===
+
+export {};
+
+=== /index.js ===
+class Foo {}
+>Foo : Foo
+>    : ^^^
+
+class Bar extends Foo {}
+>Bar : Bar
+>    : ^^^
+>Foo : Foo
+>    : ^^^
+
+module.exports = Bar;
+>module.exports = Bar : typeof Bar
+>                     : ^^^^^^^^^^
+>module.exports : typeof Bar
+>               : ^^^^^^^^^^
+>module : { exports: typeof Bar; }
+>       : ^^^^^^^^^^^^^^^^^^^^^^^^
+>exports : typeof Bar
+>        : ^^^^^^^^^^
+>Bar : typeof Bar
+>    : ^^^^^^^^^^
+

tests/baselines/reference/importHelpersCommonJSJavaScript(verbatimmodulesyntax=true).js

@@ -0,0 +1,61 @@
+//// [tests/cases/compiler/importHelpersCommonJSJavaScript.ts] ////
+
+//// [package.json]
+{
+  "name": "tslib",
+  "main": "tslib.js",
+  "module": "tslib.es6.js",
+  "jsnext:main": "tslib.es6.js",
+  "typings": "tslib.d.ts",
+  "exports": {
+      ".": {
+          "module": {
+              "types": "./modules/index.d.ts",
+              "default": "./tslib.es6.mjs"
+          },
+          "import": {
+              "node": "./modules/index.js",
+              "default": {
+                  "types": "./modules/index.d.ts",
+                  "default": "./tslib.es6.mjs"
+              }
+          },
+          "default": "./tslib.js"
+      },
+      "./*": "./*",
+      "./": "./"
+  }
+}
+
+//// [tslib.d.ts]
+export declare var __extends: any;
+
+//// [package.json]
+{ "type": "module" }
+
+//// [index.d.ts]
+export {};
+
+//// [index.js]
+class Foo {}
+
+class Bar extends Foo {}
+
+module.exports = Bar;
+
+
+//// [index.js]
+var tslib_1 = require("tslib");
+var Foo = /** @class */ (function () {
+    function Foo() {
+    }
+    return Foo;
+}());
+var Bar = /** @class */ (function (_super) {
+    tslib_1.__extends(Bar, _super);
+    function Bar() {
+        return _super !== null && _super.apply(this, arguments) || this;
+    }
+    return Bar;
+}(Foo));
+module.exports = Bar;

tests/baselines/reference/importHelpersCommonJSJavaScript(verbatimmodulesyntax=true).symbols

@@ -0,0 +1,24 @@
+//// [tests/cases/compiler/importHelpersCommonJSJavaScript.ts] ////
+
+=== /node_modules/tslib/tslib.d.ts ===
+export declare var __extends: any;
+>__extends : Symbol(__extends, Decl(tslib.d.ts, --, --))
+
+=== /node_modules/tslib/modules/index.d.ts ===
+
+export {};
+
+=== /index.js ===
+class Foo {}
+>Foo : Symbol(Foo, Decl(index.js, 0, 0))
+
+class Bar extends Foo {}
+>Bar : Symbol(Bar, Decl(index.js, 0, 12))
+>Foo : Symbol(Foo, Decl(index.js, 0, 0))
+
+module.exports = Bar;
+>module.exports : Symbol(module.exports, Decl(index.js, 0, 0))
+>module : Symbol(export=, Decl(index.js, 2, 24))
+>exports : Symbol(export=, Decl(index.js, 2, 24))
+>Bar : Symbol(Bar, Decl(index.js, 0, 12))
+

tests/baselines/reference/importHelpersCommonJSJavaScript(verbatimmodulesyntax=true).types

@@ -0,0 +1,33 @@
+//// [tests/cases/compiler/importHelpersCommonJSJavaScript.ts] ////
+
+=== /node_modules/tslib/tslib.d.ts ===
+export declare var __extends: any;
+>__extends : any
+
+=== /node_modules/tslib/modules/index.d.ts ===
+
+export {};
+
+=== /index.js ===
+class Foo {}
+>Foo : Foo
+>    : ^^^
+
+class Bar extends Foo {}
+>Bar : Bar
+>    : ^^^
+>Foo : Foo
+>    : ^^^
+
+module.exports = Bar;
+>module.exports = Bar : typeof Bar
+>                     : ^^^^^^^^^^
+>module.exports : typeof Bar
+>               : ^^^^^^^^^^
+>module : { exports: typeof Bar; }
+>       : ^^^^^^^^^^^^^^^^^^^^^^^^
+>exports : typeof Bar
+>        : ^^^^^^^^^^
+>Bar : typeof Bar
+>    : ^^^^^^^^^^
+

tests/baselines/reference/importHelpersVerbatimModuleSyntax.js

@@ -0,0 +1,53 @@
+//// [tests/cases/compiler/importHelpersVerbatimModuleSyntax.ts] ////
+
+//// [package.json]
+{
+  "name": "tslib",
+  "main": "tslib.js",
+  "module": "tslib.es6.js",
+  "jsnext:main": "tslib.es6.js",
+  "typings": "tslib.d.ts",
+  "exports": {
+      ".": {
+          "module": {
+              "types": "./modules/index.d.ts",
+              "default": "./tslib.es6.mjs"
+          },
+          "import": {
+              "node": "./modules/index.js",
+              "default": {
+                  "types": "./modules/index.d.ts",
+                  "default": "./tslib.es6.mjs"
+              }
+          },
+          "default": "./tslib.js"
+      },
+      "./*": "./*",
+      "./": "./"
+  }
+}
+
+//// [tslib.d.ts]
+export declare var __rest: any;
+
+//// [package.json]
+{ "type": "module" }
+
+//// [index.d.ts]
+export {};
+
+//// [main.cts]
+function foo(args: any) {
+  const { bar, ...extraArgs } = args;
+  return extraArgs;
+}
+export = foo;
+
+
+//// [main.cjs]
+import * as tslib_1 from "tslib";
+function foo(args) {
+    const { bar } = args, extraArgs = __rest(args, ["bar"]);
+    return extraArgs;
+}
+module.exports = foo;

tests/baselines/reference/importHelpersVerbatimModuleSyntax.symbols

@@ -0,0 +1,26 @@
+//// [tests/cases/compiler/importHelpersVerbatimModuleSyntax.ts] ////
+
+=== /node_modules/tslib/tslib.d.ts ===
+export declare var __rest: any;
+>__rest : Symbol(__rest, Decl(tslib.d.ts, --, --))
+
+=== /node_modules/tslib/modules/index.d.ts ===
+
+export {};
+
+=== /main.cts ===
+function foo(args: any) {
+>foo : Symbol(foo, Decl(main.cts, 0, 0))
+>args : Symbol(args, Decl(main.cts, 0, 13))
+
+  const { bar, ...extraArgs } = args;
+>bar : Symbol(bar, Decl(main.cts, 1, 9))
+>extraArgs : Symbol(extraArgs, Decl(main.cts, 1, 14))
+>args : Symbol(args, Decl(main.cts, 0, 13))
+
+  return extraArgs;
+>extraArgs : Symbol(extraArgs, Decl(main.cts, 1, 14))
+}
+export = foo;
+>foo : Symbol(foo, Decl(main.cts, 0, 0))
+

tests/baselines/reference/importHelpersVerbatimModuleSyntax.types

@@ -0,0 +1,30 @@
+//// [tests/cases/compiler/importHelpersVerbatimModuleSyntax.ts] ////
+
+=== /node_modules/tslib/tslib.d.ts ===
+export declare var __rest: any;
+>__rest : any
+
+=== /node_modules/tslib/modules/index.d.ts ===
+
+export {};
+
+=== /main.cts ===
+function foo(args: any) {
+>foo : (args: any) => any
+>    : ^    ^^   ^^^^^^^^
+>args : any
+
+  const { bar, ...extraArgs } = args;
+>bar : any
+>    : ^^^
+>extraArgs : any
+>          : ^^^
+>args : any
+
+  return extraArgs;
+>extraArgs : any
+}
+export = foo;
+>foo : (args: any) => any
+>    : ^    ^^   ^^^^^^^^
+

tests/cases/compiler/importHelpersBundler.ts

@@ -0,0 +1,46 @@
+// @importHelpers: true
+// @target: es2017
+// @module: esnext
+// @moduleResolution: bundler
+
+// @Filename: /node_modules/tslib/package.json
+{
+  "name": "tslib",
+  "main": "tslib.js",
+  "module": "tslib.es6.js",
+  "jsnext:main": "tslib.es6.js",
+  "typings": "tslib.d.ts",
+  "exports": {
+      ".": {
+          "module": {
+              "types": "./modules/index.d.ts",
+              "default": "./tslib.es6.mjs"
+          },
+          "import": {
+              "node": "./modules/index.js",
+              "default": {
+                  "types": "./modules/index.d.ts",
+                  "default": "./tslib.es6.mjs"
+              }
+          },
+          "default": "./tslib.js"
+      },
+      "./*": "./*",
+      "./": "./"
+  }
+}
+
+// @Filename: /node_modules/tslib/tslib.d.ts
+export {};
+
+// @Filename: /node_modules/tslib/modules/package.json
+{ "type": "module" }
+
+// @Filename: /node_modules/tslib/modules/index.d.ts
+export declare var __rest: any;
+
+// @Filename: /main.ts
+export function foo(args: any) {
+  const { bar, ...extraArgs } = args;
+  return extraArgs;
+}

tests/cases/compiler/importHelpersCommonJSJavaScript.ts

@@ -0,0 +1,48 @@
+// @checkJs: true
+// @outDir: ./out
+// @module: commonjs
+// @importHelpers: true
+// @verbatimModuleSyntax: true,false
+
+// @Filename: /node_modules/tslib/package.json
+{
+  "name": "tslib",
+  "main": "tslib.js",
+  "module": "tslib.es6.js",
+  "jsnext:main": "tslib.es6.js",
+  "typings": "tslib.d.ts",
+  "exports": {
+      ".": {
+          "module": {
+              "types": "./modules/index.d.ts",
+              "default": "./tslib.es6.mjs"
+          },
+          "import": {
+              "node": "./modules/index.js",
+              "default": {
+                  "types": "./modules/index.d.ts",
+                  "default": "./tslib.es6.mjs"
+              }
+          },
+          "default": "./tslib.js"
+      },
+      "./*": "./*",
+      "./": "./"
+  }
+}
+
+// @Filename: /node_modules/tslib/tslib.d.ts
+export declare var __extends: any;
+
+// @Filename: /node_modules/tslib/modules/package.json
+{ "type": "module" }
+
+// @Filename: /node_modules/tslib/modules/index.d.ts
+export {};
+
+// @Filename: /index.js
+class Foo {}
+
+class Bar extends Foo {}
+
+module.exports = Bar;

tests/cases/compiler/importHelpersVerbatimModuleSyntax.ts

@@ -0,0 +1,48 @@
+// @importHelpers: true
+// @target: es2017
+// @module: preserve
+// @moduleResolution: bundler
+// @verbatimModuleSyntax: true
+
+// @Filename: /node_modules/tslib/package.json
+{
+  "name": "tslib",
+  "main": "tslib.js",
+  "module": "tslib.es6.js",
+  "jsnext:main": "tslib.es6.js",
+  "typings": "tslib.d.ts",
+  "exports": {
+      ".": {
+          "module": {
+              "types": "./modules/index.d.ts",
+              "default": "./tslib.es6.mjs"
+          },
+          "import": {
+              "node": "./modules/index.js",
+              "default": {
+                  "types": "./modules/index.d.ts",
+                  "default": "./tslib.es6.mjs"
+              }
+          },
+          "default": "./tslib.js"
+      },
+      "./*": "./*",
+      "./": "./"
+  }
+}
+
+// @Filename: /node_modules/tslib/tslib.d.ts
+export declare var __rest: any;
+
+// @Filename: /node_modules/tslib/modules/package.json
+{ "type": "module" }
+
+// @Filename: /node_modules/tslib/modules/index.d.ts
+export {};
+
+// @Filename: /main.cts
+function foo(args: any) {
+  const { bar, ...extraArgs } = args;
+  return extraArgs;
+}
+export = foo;