Use explicit extensions for imports within src (#58421)

.eslintrc.json

@@ -144,7 +144,8 @@
         "local/no-in-operator": "error",
         "local/debug-assert": "error",
         "local/no-keywords": "error",
-        "local/jsdoc-format": "error"
+        "local/jsdoc-format": "error",
+        "local/js-extensions": "error"
     },
     "overrides": [
         // By default, the ESLint CLI only looks at .js files. But, it will also look at

.vscode/settings.template.json

@@ -18,6 +18,9 @@
         ".git-blame-ignore-revs"
     ],
 
+    "javascript.preferences.importModuleSpecifierEnding": "js",
+    "typescript.preferences.importModuleSpecifierEnding": "js",
+
     // Match dprint in organize/auto-imports.
     "typescript.unstable": {
         "organizeImportsCollation": "unicode",

scripts/eslint/rules/js-extensions.cjs

@@ -0,0 +1,70 @@
+const { createRule } = require("./utils.cjs");
+
+module.exports = createRule({
+    name: "js-extensions",
+    meta: {
+        docs: {
+            description: ``,
+        },
+        messages: {
+            missingJsExtension: `This relative module reference is missing a '.js' extension`,
+        },
+        schema: [],
+        type: "suggestion",
+        fixable: "code",
+    },
+    defaultOptions: [],
+
+    create(context) {
+        /** @type {(
+         *      node:
+         *          | import("@typescript-eslint/utils").TSESTree.ImportDeclaration
+         *          | import("@typescript-eslint/utils").TSESTree.ExportAllDeclaration
+         *          | import("@typescript-eslint/utils").TSESTree.ExportNamedDeclaration
+         *          | import("@typescript-eslint/utils").TSESTree.TSImportEqualsDeclaration
+         *          | import("@typescript-eslint/utils").TSESTree.TSModuleDeclaration
+         *  ) => void}
+         */
+        const check = node => {
+            let source;
+            if (node.type === "TSImportEqualsDeclaration") {
+                const moduleReference = node.moduleReference;
+                if (
+                    moduleReference.type === "TSExternalModuleReference"
+                    && moduleReference.expression.type === "Literal"
+                    && typeof moduleReference.expression.value === "string"
+                ) {
+                    source = moduleReference.expression;
+                }
+            }
+            else if (node.type === "TSModuleDeclaration") {
+                if (node.kind === "module" && node.id.type === "Literal") {
+                    source = node.id;
+                }
+            }
+            else {
+                source = node.source;
+            }
+
+            // This is not 100% accurate; this could point to a nested package, or to a directory
+            // containing an index.js file. But we don't have anything like that in our repo,
+            // so this check is good enough. Replicate this logic at your own risk.
+            if (source?.value.startsWith(".") && !/\.[cm]?js$/.test(source.value)) {
+                const quote = source.raw[0];
+                context.report({
+                    messageId: "missingJsExtension",
+                    node: source,
+                    fix: fixer => fixer.replaceText(source, `${quote}${source.value}.js${quote}`),
+                });
+            }
+        };
+
+        return {
+            ImportDeclaration: check,
+            ExportAllDeclaration: check,
+            ExportNamedDeclaration: check,
+            TSImportEqualsDeclaration: check,
+            TSModuleDeclaration: check,
+        };
+    },
+});

scripts/eslint/tests/js-extensions.cjs

@@ -0,0 +1,149 @@
+const { RuleTester } = require("./support/RuleTester.cjs");
+const rule = require("../rules/js-extensions.cjs");
+
+const ruleTester = new RuleTester({
+    parserOptions: {
+        warnOnUnsupportedTypeScriptVersion: false,
+    },
+    parser: require.resolve("@typescript-eslint/parser"),
+});
+
+ruleTester.run("js-extensions", rule, {
+    valid: [
+        {
+            code: `
+import "some-library";
+import "./a.js";
+import "./a.mjs";
+import "./a.cjs";
+import "../foo/a.js";
+import "../foo/a.mjs";
+import "../foo/a.cjs";
+        `,
+        },
+        {
+            code: `
+import * as blah from "some-library";
+import * as blah from "./a.js";
+import * as blah from "./a.mjs";
+import * as blah from "./a.cjs";
+import * as blah from "../foo/a.js";
+import * as blah from "../foo/a.mjs";
+import * as blah from "../foo/a.cjs";
+        `,
+        },
+        {
+            code: `
+export * from "some-library";
+export * from "./a.js";
+export * from "./a.mjs";
+export * from "./a.cjs";
+export * from "../foo/a.js";
+export * from "../foo/a.mjs";
+export * from "../foo/a.cjs";
+        `,
+        },
+        {
+            code: `
+import blah = require("some-library");
+import blah = require("./a.js");
+import blah = require("./a.mjs");
+import blah = require("./a.cjs");
+import blah = require("../foo/a.js");
+import blah = require("../foo/a.mjs");
+import blah = require("../foo/a.cjs");
+        `,
+        },
+    ],
+
+    invalid: [
+        {
+            code: `
+import "./a";
+import "../foo/a";
+        `,
+            errors: [
+                {
+                    messageId: "missingJsExtension",
+                    line: 2,
+                    column: 8,
+                },
+                {
+                    messageId: "missingJsExtension",
+                    line: 3,
+                    column: 8,
+                },
+            ],
+            output: `
+import "./a.js";
+import "../foo/a.js";
+        `,
+        },
+        {
+            code: `
+import * as blah from "./a";
+import * as blah from "../foo/a";
+        `,
+            errors: [
+                {
+                    messageId: "missingJsExtension",
+                    line: 2,
+                    column: 23,
+                },
+                {
+                    messageId: "missingJsExtension",
+                    line: 3,
+                    column: 23,
+                },
+            ],
+            output: `
+import * as blah from "./a.js";
+import * as blah from "../foo/a.js";
+        `,
+        },
+        {
+            code: `
+export * from "./a";
+export * from "../foo/a";
+        `,
+            errors: [
+                {
+                    messageId: "missingJsExtension",
+                    line: 2,
+                    column: 15,
+                },
+                {
+                    messageId: "missingJsExtension",
+                    line: 3,
+                    column: 15,
+                },
+            ],
+            output: `
+export * from "./a.js";
+export * from "../foo/a.js";
+        `,
+        },
+        {
+            code: `
+import blah = require("./a");
+import blah = require("../foo/a");
+        `,
+            errors: [
+                {
+                    messageId: "missingJsExtension",
+                    line: 2,
+                    column: 23,
+                },
+                {
+                    messageId: "missingJsExtension",
+                    line: 3,
+                    column: 23,
+                },
+            ],
+            output: `
+import blah = require("./a.js");
+import blah = require("../foo/a.js");
+        `,
+        },
+    ],
+});

scripts/processDiagnosticMessages.mjs

@@ -86,7 +86,7 @@ function buildInfoFileOutput(messageTable, inputFilePathRel) {
         "// <auto-generated />",
         `// generated from '${inputFilePathRel}'`,
         "",
-        'import { DiagnosticCategory, DiagnosticMessage } from "./types";',
+        'import { DiagnosticCategory, DiagnosticMessage } from "./types.js";',
         "",
         "function diag(code: number, category: DiagnosticCategory, key: string, message: string, reportsUnnecessary?: {}, elidedInCompatabilityPyramid?: boolean, reportsDeprecated?: {}): DiagnosticMessage {",
         "    return { code, category, key, message, reportsUnnecessary, elidedInCompatabilityPyramid, reportsDeprecated };",

src/compiler/_namespaces/ts.moduleSpecifiers.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the ts.moduleSpecifiers namespace. */
 
-export * from "../moduleSpecifiers";
+export * from "../moduleSpecifiers.js";

src/compiler/_namespaces/ts.performance.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the ts.performance namespace. */
 
-export * from "../performance";
+export * from "../performance.js";

src/compiler/_namespaces/ts.ts

@@ -1,79 +1,79 @@
 /* Generated file to emulate the ts namespace. */
 
-export * from "../corePublic";
-export * from "../core";
-export * from "../debug";
-export * from "../semver";
-export * from "../performanceCore";
-export * from "../perfLogger";
-export * from "../tracing";
-export * from "../types";
-export * from "../sys";
-export * from "../path";
-export * from "../diagnosticInformationMap.generated";
-export * from "../scanner";
-export * from "../utilitiesPublic";
-export * from "../utilities";
-export * from "../factory/baseNodeFactory";
-export * from "../factory/parenthesizerRules";
-export * from "../factory/nodeConverters";
-export * from "../factory/nodeFactory";
-export * from "../factory/emitNode";
-export * from "../factory/emitHelpers";
-export * from "../factory/nodeTests";
-export * from "../factory/nodeChildren";
-export * from "../factory/utilities";
-export * from "../factory/utilitiesPublic";
-export * from "../parser";
-export * from "../commandLineParser";
-export * from "../moduleNameResolver";
-export * from "../binder";
-export * from "../symbolWalker";
-export * from "../checker";
-export * from "../visitorPublic";
-export * from "../sourcemap";
-export * from "../transformers/utilities";
-export * from "../transformers/destructuring";
-export * from "../transformers/classThis";
-export * from "../transformers/namedEvaluation";
-export * from "../transformers/taggedTemplate";
-export * from "../transformers/ts";
-export * from "../transformers/classFields";
-export * from "../transformers/typeSerializer";
-export * from "../transformers/legacyDecorators";
-export * from "../transformers/esDecorators";
-export * from "../transformers/es2017";
-export * from "../transformers/es2018";
-export * from "../transformers/es2019";
-export * from "../transformers/es2020";
-export * from "../transformers/es2021";
-export * from "../transformers/esnext";
-export * from "../transformers/jsx";
-export * from "../transformers/es2016";
-export * from "../transformers/es2015";
-export * from "../transformers/generators";
-export * from "../transformers/module/module";
-export * from "../transformers/module/system";
-export * from "../transformers/module/esnextAnd2015";
-export * from "../transformers/module/impliedNodeFormatDependent";
-export * from "../transformers/declarations/diagnostics";
-export * from "../transformers/declarations";
-export * from "../transformer";
-export * from "../emitter";
-export * from "../watchUtilities";
-export * from "../program";
-export * from "../builderStatePublic";
-export * from "../builderState";
-export * from "../builder";
-export * from "../builderPublic";
-export * from "../resolutionCache";
-export * from "../watch";
-export * from "../watchPublic";
-export * from "../tsbuild";
-export * from "../tsbuildPublic";
-export * from "../executeCommandLine";
-export * from "../expressionToTypeNode";
-import * as moduleSpecifiers from "./ts.moduleSpecifiers";
+export * from "../corePublic.js";
+export * from "../core.js";
+export * from "../debug.js";
+export * from "../semver.js";
+export * from "../performanceCore.js";
+export * from "../perfLogger.js";
+export * from "../tracing.js";
+export * from "../types.js";
+export * from "../sys.js";
+export * from "../path.js";
+export * from "../diagnosticInformationMap.generated.js";
+export * from "../scanner.js";
+export * from "../utilitiesPublic.js";
+export * from "../utilities.js";
+export * from "../factory/baseNodeFactory.js";
+export * from "../factory/parenthesizerRules.js";
+export * from "../factory/nodeConverters.js";
+export * from "../factory/nodeFactory.js";
+export * from "../factory/emitNode.js";
+export * from "../factory/emitHelpers.js";
+export * from "../factory/nodeTests.js";
+export * from "../factory/nodeChildren.js";
+export * from "../factory/utilities.js";
+export * from "../factory/utilitiesPublic.js";
+export * from "../parser.js";
+export * from "../commandLineParser.js";
+export * from "../moduleNameResolver.js";
+export * from "../binder.js";
+export * from "../symbolWalker.js";
+export * from "../checker.js";
+export * from "../visitorPublic.js";
+export * from "../sourcemap.js";
+export * from "../transformers/utilities.js";
+export * from "../transformers/destructuring.js";
+export * from "../transformers/classThis.js";
+export * from "../transformers/namedEvaluation.js";
+export * from "../transformers/taggedTemplate.js";
+export * from "../transformers/ts.js";
+export * from "../transformers/classFields.js";
+export * from "../transformers/typeSerializer.js";
+export * from "../transformers/legacyDecorators.js";
+export * from "../transformers/esDecorators.js";
+export * from "../transformers/es2017.js";
+export * from "../transformers/es2018.js";
+export * from "../transformers/es2019.js";
+export * from "../transformers/es2020.js";
+export * from "../transformers/es2021.js";
+export * from "../transformers/esnext.js";
+export * from "../transformers/jsx.js";
+export * from "../transformers/es2016.js";
+export * from "../transformers/es2015.js";
+export * from "../transformers/generators.js";
+export * from "../transformers/module/module.js";
+export * from "../transformers/module/system.js";
+export * from "../transformers/module/esnextAnd2015.js";
+export * from "../transformers/module/impliedNodeFormatDependent.js";
+export * from "../transformers/declarations/diagnostics.js";
+export * from "../transformers/declarations.js";
+export * from "../transformer.js";
+export * from "../emitter.js";
+export * from "../watchUtilities.js";
+export * from "../program.js";
+export * from "../builderStatePublic.js";
+export * from "../builderState.js";
+export * from "../builder.js";
+export * from "../builderPublic.js";
+export * from "../resolutionCache.js";
+export * from "../watch.js";
+export * from "../watchPublic.js";
+export * from "../tsbuild.js";
+export * from "../tsbuildPublic.js";
+export * from "../executeCommandLine.js";
+export * from "../expressionToTypeNode.js";
+import * as moduleSpecifiers from "./ts.moduleSpecifiers.js";
 export { moduleSpecifiers };
-import * as performance from "./ts.performance";
+import * as performance from "./ts.performance.js";
 export { performance };

src/compiler/binder.ts

@@ -320,8 +320,8 @@ import {
     VariableDeclaration,
     WhileStatement,
     WithStatement,
-} from "./_namespaces/ts";
-import * as performance from "./_namespaces/ts.performance";
+} from "./_namespaces/ts.js";
+import * as performance from "./_namespaces/ts.performance.js";
 
 /** @internal */
 export const enum ModuleInstanceState {

src/compiler/builder.ts

@@ -81,7 +81,7 @@ import {
     tryAddToSet,
     WriteFileCallback,
     WriteFileCallbackData,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export interface ReusableDiagnostic extends ReusableDiagnosticRelatedInformation {

src/compiler/builderPublic.ts

@@ -16,7 +16,7 @@ import {
     SavedBuildProgramEmitState,
     SourceFile,
     WriteFileCallback,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 export type AffectedFileResult<T> = { result: T; affected: SourceFile | Program; } | undefined;
 

src/compiler/builderState.ts

@@ -31,7 +31,7 @@ import {
     Symbol,
     toPath,
     TypeChecker,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export function getFileEmitOutput(

src/compiler/builderStatePublic.ts

@@ -1,7 +1,7 @@
 import {
     Diagnostic,
     WriteFileCallbackData,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 export interface EmitOutput {
     outputFiles: OutputFile[];

src/compiler/checker.ts

@@ -1105,9 +1105,9 @@ import {
     WideningContext,
     WithStatement,
     YieldExpression,
-} from "./_namespaces/ts";
-import * as moduleSpecifiers from "./_namespaces/ts.moduleSpecifiers";
-import * as performance from "./_namespaces/ts.performance";
+} from "./_namespaces/ts.js";
+import * as moduleSpecifiers from "./_namespaces/ts.moduleSpecifiers.js";
+import * as performance from "./_namespaces/ts.performance.js";
 
 const ambientModuleSymbolRegex = /^".+"$/;
 const anon = "(anonymous)" as __String & string;

src/compiler/commandLineParser.ts

@@ -121,7 +121,7 @@ import {
     WatchDirectoryKind,
     WatchFileKind,
     WatchOptions,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export const compileOnSaveCommandLineOption: CommandLineOption = {

src/compiler/core.ts

@@ -9,7 +9,7 @@ import {
     SortedArray,
     SortedReadonlyArray,
     TextSpan,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export const emptyArray: never[] = [] as never[];

src/compiler/debug.ts

@@ -1,4 +1,4 @@
-import * as ts from "./_namespaces/ts";
+import * as ts from "./_namespaces/ts.js";
 import {
     AnyFunction,
     AssertionLevel,
@@ -91,7 +91,7 @@ import {
     unescapeLeadingUnderscores,
     VarianceFlags,
     zipWith,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export enum LogLevel {

src/compiler/emitter.ts

@@ -1,4 +1,4 @@
-import * as ts from "./_namespaces/ts";
+import * as ts from "./_namespaces/ts.js";
 import {
     AccessorDeclaration,
     ArrayBindingPattern,
@@ -420,8 +420,8 @@ import {
     writeCommentRange,
     writeFile,
     YieldExpression,
-} from "./_namespaces/ts";
-import * as performance from "./_namespaces/ts.performance";
+} from "./_namespaces/ts.js";
+import * as performance from "./_namespaces/ts.performance.js";
 
 const brackets = createBracketsMap();
 

src/compiler/executeCommandLine.ts

@@ -86,8 +86,8 @@ import {
     WatchCompilerHost,
     WatchOfConfigFile,
     WatchOptions,
-} from "./_namespaces/ts";
-import * as performance from "./performance";
+} from "./_namespaces/ts.js";
+import * as performance from "./performance.js";
 
 interface Statistic {
     name: string;

src/compiler/expressionToTypeNode.ts

@@ -64,7 +64,7 @@ import {
     TypeParameterDeclaration,
     UnionTypeNode,
     VariableDeclaration,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export function createSyntacticTypeNodeBuilder(options: CompilerOptions, resolver: SyntacticTypeNodeBuilderResolver) {

src/compiler/factory/baseNodeFactory.ts

@@ -2,7 +2,7 @@ import {
     Node,
     objectAllocator,
     SyntaxKind,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /**
  * A `BaseNodeFactory` is an abstraction over an `ObjectAllocator` that handles caching `Node` constructors

src/compiler/factory/emitHelpers.ts

@@ -35,7 +35,7 @@ import {
     TextRange,
     TransformationContext,
     UnscopedEmitHelper,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export const enum PrivateIdentifierKind {

src/compiler/factory/emitNode.ts

@@ -26,7 +26,7 @@ import {
     TextRange,
     TypeNode,
     TypeParameterDeclaration,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /**
  * Associates a node with the current transformation, initializing

src/compiler/factory/nodeChildren.ts

@@ -2,7 +2,7 @@ import {
     emptyArray,
     isNodeKind,
     Node,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 const nodeChildren = new WeakMap<Node, readonly Node[] | undefined>();
 

src/compiler/factory/nodeConverters.ts

@@ -35,7 +35,7 @@ import {
     setStartsOnNewLine,
     setTextRange,
     SyntaxKind,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export function createNodeConverters(factory: NodeFactory): NodeConverters {

src/compiler/factory/nodeFactory.ts

@@ -456,7 +456,7 @@ import {
     WhileStatement,
     WithStatement,
     YieldExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 let nextAutoGenerateId = 0;
 

src/compiler/factory/nodeTests.ts

@@ -227,7 +227,7 @@ import {
     WhileStatement,
     WithStatement,
     YieldExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 // Literals
 

src/compiler/factory/parenthesizerRules.ts

@@ -48,7 +48,7 @@ import {
     SyntaxKind,
     TypeNode,
     UnaryExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export function createParenthesizerRules(factory: NodeFactory): ParenthesizerRules {

src/compiler/factory/utilities.ts

@@ -180,7 +180,7 @@ import {
     TransformFlags,
     TypeNode,
     WrappedExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 // Compound nodes
 

src/compiler/factory/utilitiesPublic.ts

@@ -5,7 +5,7 @@ import {
     setTextRangePosEnd,
     SyntaxKind,
     TextRange,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 export function setTextRange<T extends TextRange>(range: T, location: TextRange | undefined): T {
     return location ? setTextRangePosEnd(range, location.pos, location.end) : range;

src/compiler/moduleNameResolver.ts

@@ -108,7 +108,7 @@ import {
     version,
     versionMajorMinor,
     VersionRange,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export function trace(host: ModuleResolutionHost, message: DiagnosticMessage, ...args: any[]): void {

src/compiler/moduleSpecifiers.ts

@@ -124,7 +124,7 @@ import {
     tryParsePatterns,
     TypeChecker,
     UserPreferences,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 // Used by importFixes, getEditsForFileRename, and declaration emit to synthesize import module specifiers.
 

src/compiler/parser.ts

@@ -397,8 +397,8 @@ import {
     WhileStatement,
     WithStatement,
     YieldExpression,
-} from "./_namespaces/ts";
-import * as performance from "./_namespaces/ts.performance";
+} from "./_namespaces/ts.js";
+import * as performance from "./_namespaces/ts.performance.js";
 
 const enum SignatureFlags {
     None = 0,

src/compiler/path.ts

@@ -16,7 +16,7 @@ import {
     Path,
     some,
     startsWith,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /**
  * Internally, we represent paths as strings with '/' as the directory separator.

src/compiler/performance.ts

@@ -7,7 +7,7 @@ import {
     System,
     timestamp,
     tryGetNativePerformanceHooks,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** Performance measurements for the compiler. */
 

src/compiler/performanceCore.ts

@@ -1,4 +1,4 @@
-import { isNodeLikeSystem } from "./_namespaces/ts";
+import { isNodeLikeSystem } from "./_namespaces/ts.js";
 
 // The following definitions provide the minimum compatible support for the Web Performance User Timings API
 // between browsers and NodeJS:

src/compiler/program.ts

@@ -328,8 +328,8 @@ import {
     WriteFileCallback,
     WriteFileCallbackData,
     writeFileEnsuringDirectories,
-} from "./_namespaces/ts";
-import * as performance from "./_namespaces/ts.performance";
+} from "./_namespaces/ts.js";
+import * as performance from "./_namespaces/ts.performance.js";
 
 export function findConfigFile(searchPath: string, fileExists: (fileName: string) => boolean, configName = "tsconfig.json"): string | undefined {
     return forEachAncestorDirectory(searchPath, ancestor => {

src/compiler/resolutionCache.ts

@@ -76,7 +76,7 @@ import {
     trace,
     updateResolutionField,
     WatchDirectoryFlags,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export interface HasInvalidatedFromResolutionCache {

src/compiler/scanner.ts

@@ -33,7 +33,7 @@ import {
     SyntaxKind,
     TextRange,
     TokenFlags,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 export type ErrorCallback = (message: DiagnosticMessage, length: number, arg0?: any) => void;
 

src/compiler/semver.ts

@@ -8,7 +8,7 @@ import {
     isArray,
     map,
     some,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 // https://semver.org/#spec-item-2
 // > A normal version number MUST take the form X.Y.Z where X, Y, and Z are non-negative

src/compiler/sourcemap.ts

@@ -24,8 +24,8 @@ import {
     sortAndDeduplicate,
     SortedReadonlyArray,
     SourceMapGenerator,
-} from "./_namespaces/ts";
-import * as performance from "./_namespaces/ts.performance";
+} from "./_namespaces/ts.js";
+import * as performance from "./_namespaces/ts.performance.js";
 
 /** @internal */
 export interface SourceMapGeneratorOptions {

src/compiler/symbolWalker.ts

@@ -24,7 +24,7 @@ import {
     TypeQueryNode,
     TypeReference,
     UnionOrIntersectionType,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export function createGetSymbolWalker(

src/compiler/sys.ts

@@ -46,7 +46,7 @@ import {
     WatchFileKind,
     WatchOptions,
     writeFileEnsuringDirectories,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 declare function setTimeout(handler: (...args: any[]) => void, timeout: number): any;
 declare function clearTimeout(handle: any): void;

src/compiler/tracing.ts

@@ -20,8 +20,8 @@ import {
     TypeReference,
     unescapeLeadingUnderscores,
     UnionType,
-} from "./_namespaces/ts";
-import * as performance from "./_namespaces/ts.performance";
+} from "./_namespaces/ts.js";
+import * as performance from "./_namespaces/ts.performance.js";
 
 /* Tracing events for the compiler. */
 

src/compiler/transformer.ts

@@ -72,8 +72,8 @@ import {
     transformSystemModule,
     transformTypeScript,
     VariableDeclaration,
-} from "./_namespaces/ts";
-import * as performance from "./_namespaces/ts.performance";
+} from "./_namespaces/ts.js";
+import * as performance from "./_namespaces/ts.performance.js";
 
 function getModuleTransformer(moduleKind: ModuleKind): TransformerFactory<SourceFile | Bundle> {
     switch (moduleKind) {

src/compiler/transformers/classFields.ts

@@ -225,7 +225,7 @@ import {
     Visitor,
     visitParameterList,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 const enum ClassPropertySubstitutionFlags {
     /**

src/compiler/transformers/classThis.ts

@@ -21,7 +21,7 @@ import {
     Statement,
     SyntaxKind,
     ThisExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /**
  * Creates a class `static {}` block used to assign the static `this` to a `_classThis` (or similar) variable.

src/compiler/transformers/declarations.ts

@@ -210,7 +210,7 @@ import {
     visitNode,
     visitNodes,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export function getDeclarationDiagnostics(host: EmitHost, resolver: EmitResolver, file: SourceFile | undefined): DiagnosticWithLocation[] | undefined {

src/compiler/transformers/declarations/diagnostics.ts

@@ -87,7 +87,7 @@ import {
     TypeAliasDeclaration,
     TypeParameterDeclaration,
     VariableDeclaration,
-} from "../../_namespaces/ts";
+} from "../../_namespaces/ts.js";
 
 /** @internal */
 export type GetSymbolAccessibilityDiagnostic = (symbolAccessibilityResult: SymbolAccessibilityResult) => SymbolAccessibilityDiagnostic | undefined;

src/compiler/transformers/destructuring.ts

@@ -60,7 +60,7 @@ import {
     VariableDeclaration,
     visitNode,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 interface FlattenContext {
     context: TransformationContext;

src/compiler/transformers/es2015.ts

@@ -215,7 +215,7 @@ import {
     VoidExpression,
     WhileStatement,
     YieldExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 const enum ES2015SubstitutionFlags {
     /** Enables substitutions for captured `this` */

src/compiler/transformers/es2016.ts

@@ -15,7 +15,7 @@ import {
     visitEachChild,
     visitNode,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export function transformES2016(context: TransformationContext): (x: SourceFile | Bundle) => SourceFile | Bundle {

src/compiler/transformers/es2017.ts

@@ -99,7 +99,7 @@ import {
     visitNodes,
     visitParameterList,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 type SuperContainer = ClassDeclaration | MethodDeclaration | GetAccessorDeclaration | SetAccessorDeclaration | ConstructorDeclaration;
 

src/compiler/transformers/es2018.ts

@@ -110,7 +110,7 @@ import {
     VisitResult,
     VoidExpression,
     YieldExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 const enum ESNextSubstitutionFlags {
     /** Enables substitutions for async methods with `super` calls. */

src/compiler/transformers/es2019.ts

@@ -11,7 +11,7 @@ import {
     visitEachChild,
     visitNode,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export function transformES2019(context: TransformationContext): (x: SourceFile | Bundle) => SourceFile | Bundle {

src/compiler/transformers/es2020.ts

@@ -36,7 +36,7 @@ import {
     visitNode,
     visitNodes,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export function transformES2020(context: TransformationContext): (x: SourceFile | Bundle) => SourceFile | Bundle {

src/compiler/transformers/es2021.ts

@@ -19,7 +19,7 @@ import {
     visitEachChild,
     visitNode,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export function transformES2021(context: TransformationContext): (x: SourceFile | Bundle) => SourceFile | Bundle {

src/compiler/transformers/esDecorators.ts

@@ -188,7 +188,7 @@ import {
     Visitor,
     VisitResult,
     WrappedExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 // Class/Decorator evaluation order, as it pertains to this transformer:
 //

src/compiler/transformers/esnext.ts

@@ -61,7 +61,7 @@ import {
     visitNode,
     visitNodes,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 const enum UsingKind {
     None,

src/compiler/transformers/generators.ts

@@ -95,7 +95,7 @@ import {
     WhileStatement,
     WithStatement,
     YieldExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 // Transforms generator functions into a compatible ES5 representation with similar runtime
 // semantics. This is accomplished by first transforming the body of each generator

src/compiler/transformers/jsx.ts

@@ -84,7 +84,7 @@ import {
     visitEachChild,
     visitNode,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export function transformJsx(context: TransformationContext): (x: SourceFile | Bundle) => SourceFile | Bundle {

src/compiler/transformers/legacyDecorators.ts

@@ -82,7 +82,7 @@ import {
     visitNode,
     visitNodes,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export function transformLegacyDecorators(context: TransformationContext): (x: SourceFile | Bundle) => SourceFile | Bundle {

src/compiler/transformers/module/esnextAnd2015.ts

@@ -49,7 +49,7 @@ import {
     visitEachChild,
     visitNodes,
     VisitResult,
-} from "../../_namespaces/ts";
+} from "../../_namespaces/ts.js";
 
 /** @internal */
 export function transformECMAScriptModule(context: TransformationContext): (x: SourceFile | Bundle) => SourceFile | Bundle {

src/compiler/transformers/module/impliedNodeFormatDependent.ts

@@ -11,7 +11,7 @@ import {
     TransformationContext,
     transformECMAScriptModule,
     transformModule,
-} from "../../_namespaces/ts";
+} from "../../_namespaces/ts.js";
 
 /** @internal */
 export function transformImpliedNodeFormatDependentModule(context: TransformationContext) {

src/compiler/transformers/module/module.ts

@@ -161,7 +161,7 @@ import {
     VisitResult,
     WhileStatement,
     WithStatement,
-} from "../../_namespaces/ts";
+} from "../../_namespaces/ts.js";
 
 /** @internal */
 export function transformModule(context: TransformationContext): (x: SourceFile | Bundle) => SourceFile | Bundle {

src/compiler/transformers/module/system.ts

@@ -128,7 +128,7 @@ import {
     VisitResult,
     WhileStatement,
     WithStatement,
-} from "../../_namespaces/ts";
+} from "../../_namespaces/ts.js";
 
 /** @internal */
 export function transformSystemModule(context: TransformationContext): (x: SourceFile | Bundle) => SourceFile | Bundle {

src/compiler/transformers/namedEvaluation.ts

@@ -48,7 +48,7 @@ import {
     TransformationContext,
     VariableDeclaration,
     WrappedExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /**
  * Gets a string literal to use as the assigned name of an anonymous class or function declaration.

src/compiler/transformers/taggedTemplate.ts

@@ -23,7 +23,7 @@ import {
     visitEachChild,
     visitNode,
     Visitor,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export enum ProcessLevel {

src/compiler/transformers/ts.ts

@@ -201,7 +201,7 @@ import {
     visitNodes,
     visitParameterList,
     VisitResult,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /**
  * Indicates whether to emit type metadata in the new format.

src/compiler/transformers/typeSerializer.ts

@@ -67,7 +67,7 @@ import {
     TypeReferenceSerializationKind,
     UnionOrIntersectionTypeNode,
     VoidExpression,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export type SerializedEntityName =

src/compiler/transformers/utilities.ts

@@ -90,7 +90,7 @@ import {
     unorderedRemoveItem,
     VariableDeclaration,
     VariableStatement,
-} from "../_namespaces/ts";
+} from "../_namespaces/ts.js";
 
 /** @internal */
 export function getOriginalNodeId(node: Node) {

src/compiler/tsbuild.ts

@@ -4,7 +4,7 @@ import {
     fileExtensionIs,
     Path,
     ResolvedConfigFileName,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export enum UpToDateStatusType {

src/compiler/tsbuildPublic.ts

@@ -126,8 +126,8 @@ import {
     WildcardDirectoryWatcher,
     writeFile,
     WriteFileCallback,
-} from "./_namespaces/ts";
-import * as performance from "./_namespaces/ts.performance";
+} from "./_namespaces/ts.js";
+import * as performance from "./_namespaces/ts.performance.js";
 
 const minimumDate = new Date(-8640000000000000);
 const maximumDate = new Date(8640000000000000);

src/compiler/types.ts

@@ -16,7 +16,7 @@ import {
     ProgramBuildInfo,
     SymlinkCache,
     ThisContainer,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 // branded string type used to store absolute, normalized and canonicalized paths
 // arbitrary file name can be converted to Path via toPath function

src/compiler/utilities.ts

@@ -585,7 +585,7 @@ import {
     WriteFileCallback,
     WriteFileCallbackData,
     YieldExpression,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /** @internal */
 export const resolvingEmptyArray: never[] = [];

src/compiler/utilitiesPublic.ts

@@ -295,7 +295,7 @@ import {
     TypeReferenceType,
     UnaryExpression,
     VariableDeclaration,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 export function isExternalModuleNameRelative(moduleName: string): boolean {
     // TypeScript 1.0 spec (April 2014): 11.2.1

src/compiler/visitorPublic.ts

@@ -102,7 +102,7 @@ import {
     SyntaxKind,
     TransformationContext,
     Visitor,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /**
  * Visits a Node using the supplied visitor, possibly returning a new Node in its place.

src/compiler/watch.ts

@@ -106,7 +106,7 @@ import {
     WatchStatusReporter,
     whitespaceOrMapCommentRegExp,
     WriteFileCallback,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 const sysFormatDiagnosticsHost: FormatDiagnosticsHost | undefined = sys ? {
     getCurrentDirectory: () => sys.getCurrentDirectory(),

src/compiler/watchPublic.ts

@@ -94,7 +94,7 @@ import {
     WatchType,
     WatchTypeRegistry,
     WildcardDirectoryWatcher,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 export interface ReadBuildProgramHost {
     useCaseSensitiveFileNames(): boolean;

src/compiler/watchUtilities.ts

@@ -56,7 +56,7 @@ import {
     WatchDirectoryFlags,
     WatchFileKind,
     WatchOptions,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 /**
  * Partial interface of the System thats needed to support the caching of directory structure

src/deprecatedCompat/_namespaces/ts.ts

@@ -1,4 +1,4 @@
 /* Generated file to emulate the ts namespace. */
 
-export * from "../../compiler/_namespaces/ts";
-export * from "../deprecations";
+export * from "../../compiler/_namespaces/ts.js";
+export * from "../deprecations.js";

src/deprecatedCompat/deprecate.ts

@@ -5,7 +5,7 @@ import {
     noop,
     Version,
     version,
-} from "./_namespaces/ts";
+} from "./_namespaces/ts.js";
 
 export let enableDeprecationWarnings = true;
 

src/deprecatedCompat/deprecations.ts

@@ -2,8 +2,8 @@ import {
     hasProperty,
     UnionToIntersection,
     Version,
-} from "./_namespaces/ts";
-import { deprecate } from "./deprecate";
+} from "./_namespaces/ts.js";
+import { deprecate } from "./deprecate.js";
 
 /** @internal */
 export interface DeprecationOptions {

src/harness/_namespaces/FourSlash.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the FourSlash namespace. */
 
-export * from "../fourslashImpl";
+export * from "../fourslashImpl.js";

src/harness/_namespaces/FourSlashInterface.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the FourSlashInterface namespace. */
 
-export * from "../fourslashInterfaceImpl";
+export * from "../fourslashInterfaceImpl.js";

src/harness/_namespaces/Harness.LanguageService.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the Harness.LanguageService namespace. */
 
-export * from "../harnessLanguageService";
+export * from "../harnessLanguageService.js";

src/harness/_namespaces/Harness.SourceMapRecorder.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the Harness.SourceMapRecorder namespace. */
 
-export * from "../sourceMapRecorder";
+export * from "../sourceMapRecorder.js";

src/harness/_namespaces/Harness.ts

@@ -1,9 +1,9 @@
 /* Generated file to emulate the Harness namespace. */
 
-export * from "../runnerbase";
-export * from "../harnessIO";
-export * from "../typeWriter";
-import * as LanguageService from "./Harness.LanguageService";
+export * from "../runnerbase.js";
+export * from "../harnessIO.js";
+export * from "../typeWriter.js";
+import * as LanguageService from "./Harness.LanguageService.js";
 export { LanguageService };
-import * as SourceMapRecorder from "./Harness.SourceMapRecorder";
+import * as SourceMapRecorder from "./Harness.SourceMapRecorder.js";
 export { SourceMapRecorder };

src/harness/_namespaces/Utils.ts

@@ -1,5 +1,5 @@
 /* Generated file to emulate the Utils namespace. */
 
-export * from "../util";
-export * from "../findUpDir";
-export * from "../harnessUtils";
+export * from "../util.js";
+export * from "../findUpDir.js";
+export * from "../harnessUtils.js";

src/harness/_namespaces/collections.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the collections namespace. */
 
-export * from "../collectionsImpl";
+export * from "../collectionsImpl.js";

src/harness/_namespaces/compiler.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the compiler namespace. */
 
-export * from "../compilerImpl";
+export * from "../compilerImpl.js";

src/harness/_namespaces/documents.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the documents namespace. */
 
-export * from "../documentsUtil";
+export * from "../documentsUtil.js";

src/harness/_namespaces/evaluator.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the evaluator namespace. */
 
-export * from "../evaluatorImpl";
+export * from "../evaluatorImpl.js";

src/harness/_namespaces/fakes.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the fakes namespace. */
 
-export * from "../fakesHosts";
+export * from "../fakesHosts.js";

src/harness/_namespaces/ts.server.ts

@@ -1,6 +1,6 @@
 /* Generated file to emulate the ts.server namespace. */
 
-export * from "../../jsTyping/_namespaces/ts.server";
-export * from "../../server/_namespaces/ts.server";
-export * from "../../typingsInstallerCore/_namespaces/ts.server";
-export * from "../client";
+export * from "../../jsTyping/_namespaces/ts.server.js";
+export * from "../../server/_namespaces/ts.server.js";
+export * from "../../typingsInstallerCore/_namespaces/ts.server.js";
+export * from "../client.js";

src/harness/_namespaces/ts.ts

@@ -1,11 +1,11 @@
 /* Generated file to emulate the ts namespace. */
 
-export * from "../../compiler/_namespaces/ts";
-export * from "../../services/_namespaces/ts";
-export * from "../../jsTyping/_namespaces/ts";
-export * from "../../server/_namespaces/ts";
-export * from "../../typingsInstallerCore/_namespaces/ts";
-export * from "../../deprecatedCompat/_namespaces/ts";
-export * from "../harnessGlobals";
-import * as server from "./ts.server";
+export * from "../../compiler/_namespaces/ts.js";
+export * from "../../services/_namespaces/ts.js";
+export * from "../../jsTyping/_namespaces/ts.js";
+export * from "../../server/_namespaces/ts.js";
+export * from "../../typingsInstallerCore/_namespaces/ts.js";
+export * from "../../deprecatedCompat/_namespaces/ts.js";
+export * from "../harnessGlobals.js";
+import * as server from "./ts.server.js";
 export { server };

src/harness/_namespaces/vfs.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the vfs namespace. */
 
-export * from "../vfsUtil";
+export * from "../vfsUtil.js";

src/harness/_namespaces/vpath.ts

@@ -1,3 +1,3 @@
 /* Generated file to emulate the vpath namespace. */
 
-export * from "../vpathUtil";
+export * from "../vpathUtil.js";

src/harness/client.ts

@@ -73,8 +73,8 @@ import {
     TodoComment,
     TodoCommentDescriptor,
     UserPreferences,
-} from "./_namespaces/ts";
-import { protocol } from "./_namespaces/ts.server";
+} from "./_namespaces/ts.js";
+import { protocol } from "./_namespaces/ts.server.js";
 
 export interface SessionClientHost extends LanguageServiceHost {
     writeMessage(message: string): void;

src/harness/collectionsImpl.ts

@@ -1,4 +1,4 @@
-import * as ts from "./_namespaces/ts";
+import * as ts from "./_namespaces/ts.js";
 
 export interface SortOptions<T> {
     comparer: (a: T, b: T) => number;