fix(transformer): remove unused isCoreModule

CHANGELOG.md

@@ -82,8 +82,9 @@
 - `[jest-reporters]` [**BREAKING**] Make `node-notifier` a peer dependency ([#10977](https://github.com/facebook/jest/pull/10977))
 - `[jest-resolve, jest-runtime]` [**BREAKING**] Use `Map`s instead of objects for all cached resources ([#10968](https://github.com/facebook/jest/pull/10968))
 - `[jest-runner]` [**BREAKING**] Migrate to ESM ([#10900](https://github.com/facebook/jest/pull/10900))
-- `[jest-runtime]` [**BREAKING**] Remove deprecated and unnused `getSourceMapInfo` from Runtime ([#9969](https://github.com/facebook/jest/pull/9969))
+- `[jest-runtime]` [**BREAKING**] Remove deprecated and unused `getSourceMapInfo` from Runtime ([#9969](https://github.com/facebook/jest/pull/9969))
 - `[jest-runtime]` Detect reexports from CJS as named exports in ESM ([#10988](https://github.com/facebook/jest/pull/10988))
+- `[jest-transformer]` [**BREAKING**] Remove unused `isCoreModule` option ([#11166](https://github.com/facebook/jest/pull/11166))
 - `[jest-util]` No longer checking `enumerable` when adding `process.domain` ([#10862](https://github.com/facebook/jest/pull/10862))
 - `[jest-validate]` [**BREAKING**] Remove `recursiveBlacklist ` option in favor of previously introduced `recursiveDenylist` ([#10650](https://github.com/facebook/jest/pull/10650))
 

packages/jest-transform/src/ScriptTransformer.ts

@@ -391,7 +391,7 @@ export default class ScriptTransformer {
     transformOptions: ReducedTransformOptions,
     fileSource?: string,
   ): TransformResult {
-    const {isCoreModule, isInternalModule} = options;
+    const {isInternalModule} = options;
     let fileContent = fileSource ?? this._cacheFS.get(filename);
     if (!fileContent) {
       fileContent = fs.readFileSync(filename, 'utf8');
@@ -404,7 +404,6 @@ export default class ScriptTransformer {
 
     const willTransform =
       !isInternalModule &&
-      !isCoreModule &&
       (transformOptions.instrument || this.shouldTransform(filename));
 
     try {
@@ -434,21 +433,17 @@ export default class ScriptTransformer {
     options: Options,
     fileSource?: string,
   ): TransformResult {
-    let scriptCacheKey = undefined;
-    let instrument = false;
-
-    if (!options.isCoreModule) {
-      instrument =
-        options.coverageProvider === 'babel' &&
-        shouldInstrument(filename, options, this._config);
-      scriptCacheKey = getScriptCacheKey(filename, instrument);
-      const result = this._cache.transformedFiles.get(scriptCacheKey);
-      if (result) {
-        return result;
-      }
+    const instrument =
+      options.coverageProvider === 'babel' &&
+      shouldInstrument(filename, options, this._config);
+    const scriptCacheKey = getScriptCacheKey(filename, instrument);
+
+    let result = this._cache.transformedFiles.get(scriptCacheKey);
+    if (result) {
+      return result;
     }
 
-    const result = this._transformAndBuildScript(
+    result = this._transformAndBuildScript(
       filename,
       options,
       {...options, instrument},
@@ -467,9 +462,8 @@ export default class ScriptTransformer {
     options: Options,
     fileSource: string,
   ): string {
-    const {isCoreModule, isInternalModule} = options;
-    const willTransform =
-      !isInternalModule && !isCoreModule && this.shouldTransform(filename);
+    const {isInternalModule} = options;
+    const willTransform = !isInternalModule && this.shouldTransform(filename);
 
     if (willTransform) {
       const {code: transformedJsonSource} = this.transformSource(

packages/jest-transform/src/__tests__/ScriptTransformer.test.ts

@@ -278,25 +278,6 @@ describe('ScriptTransformer', () => {
     );
   });
 
-  it('does not transform Node core modules', () => {
-    jest.mock('../shouldInstrument');
-
-    const shouldInstrument = require('../shouldInstrument').default;
-    const scriptTransformer = new ScriptTransformer(config);
-    const fsSourceCode = 'muaha, fake source!';
-
-    const response = scriptTransformer.transform(
-      'fs',
-      {...getCoverageOptions(), isCoreModule: true},
-      fsSourceCode,
-    );
-
-    expect(response.code).toEqual(fsSourceCode);
-
-    // Native files should never be transformed.
-    expect(shouldInstrument).toHaveBeenCalledTimes(0);
-  });
-
   it(
     "throws an error if `process` doesn't return a string or an object" +
       'containing `code` key with processed string',

packages/jest-transform/src/types.ts

@@ -8,23 +8,23 @@
 import type {RawSourceMap} from 'source-map';
 import type {Config, TransformTypes} from '@jest/types';
 
-export type ShouldInstrumentOptions = Pick<
-  Config.GlobalConfig,
-  | 'collectCoverage'
-  | 'collectCoverageFrom'
-  | 'collectCoverageOnlyFrom'
-  | 'coverageProvider'
-> & {
+export interface ShouldInstrumentOptions
+  extends Pick<
+    Config.GlobalConfig,
+    | 'collectCoverage'
+    | 'collectCoverageFrom'
+    | 'collectCoverageOnlyFrom'
+    | 'coverageProvider'
+  > {
   changedFiles?: Set<Config.Path>;
   sourcesRelatedToTestsInChangedFiles?: Set<Config.Path>;
-};
+}
 
-export type Options = ShouldInstrumentOptions &
-  Partial<{
-    isCoreModule: boolean;
-    isInternalModule: boolean;
-  }> &
-  CallerTransformOptions;
+export interface Options
+  extends ShouldInstrumentOptions,
+    CallerTransformOptions {
+  isInternalModule?: boolean;
+}
 
 // This is fixed in source-map@0.7.x, but we can't upgrade yet since it's async
 interface FixedRawSourceMap extends Omit<RawSourceMap, 'version'> {