fix(compiler): initialize compiler with .ts/.tsx/.d.ts files only

src/__mocks__/thing.ts

@@ -1,7 +1,10 @@
+// @ts-expect-error testing purpose
+import babelFooCfg from './babel-foo.config'
 import { getFoo } from './thing1'
 import { getFooBar } from './thing1'
 import { getBar } from './thing2'
 
 getFoo('foo')
 getBar('bar')
 getFooBar('foobar')
+getFoo(JSON.stringify(babelFooCfg.presets))

src/compiler/__snapshots__/ts-compiler.spec.ts.snap

@@ -36,12 +36,33 @@ const App = () => {
 `;
 
 exports[`TsCompiler isolatedModule false should compile codes with useESM true 1`] = `
-"import { getFoo } from './thing1';
+"// @ts-expect-error testing purpose
+import babelFooCfg from './babel-foo.config';
+import { getFoo } from './thing1';
 import { getFooBar } from './thing1';
 import { getBar } from './thing2';
 getFoo('foo');
 getBar('bar');
 getFooBar('foobar');
+getFoo(JSON.stringify(babelFooCfg.presets));
+//# "
+`;
+
+exports[`TsCompiler isolatedModule false should compile ts file which has an existing js file 1`] = `
+"\\"use strict\\";
+var __importDefault = (this && this.__importDefault) || function (mod) {
+    return (mod && mod.__esModule) ? mod : { \\"default\\": mod };
+};
+Object.defineProperty(exports, \\"__esModule\\", { value: true });
+// @ts-expect-error testing purpose
+const babel_foo_config_1 = __importDefault(require(\\"./babel-foo.config\\"));
+const thing1_1 = require(\\"./thing1\\");
+const thing1_2 = require(\\"./thing1\\");
+const thing2_1 = require(\\"./thing2\\");
+thing1_1.getFoo('foo');
+thing2_1.getBar('bar');
+thing1_2.getFooBar('foobar');
+thing1_1.getFoo(JSON.stringify(babel_foo_config_1.default.presets));
 //# "
 `;
 
@@ -73,11 +94,14 @@ exports.default = 42;
 `;
 
 exports[`TsCompiler isolatedModule true should transpile code with useESM true 1`] = `
-"import { getFoo } from './thing1';
+"// @ts-expect-error testing purpose
+import babelFooCfg from './babel-foo.config';
+import { getFoo } from './thing1';
 import { getFooBar } from './thing1';
 import { getBar } from './thing2';
 getFoo('foo');
 getBar('bar');
 getFooBar('foobar');
+getFoo(JSON.stringify(babelFooCfg.presets));
 //# "
 `;

src/compiler/ts-compiler.spec.ts

@@ -1,11 +1,13 @@
 import { readFileSync } from 'fs'
 import { join, normalize } from 'path'
 
-import { makeCompiler } from '../__helpers__/fakers'
+import { createConfigSet, makeCompiler } from '../__helpers__/fakers'
 import { logTargetMock } from '../__helpers__/mocks'
 import { mockFolder } from '../__helpers__/path'
 import ProcessedSource from '../__helpers__/processed-source'
 
+import { TsCompiler } from './ts-compiler'
+
 const logTarget = logTargetMock()
 
 describe('TsCompiler', () => {
@@ -236,6 +238,20 @@ const t: string = f(5)
       expect(compiler._initialCompilerOptions.allowSyntheticDefaultImports).not.toEqual(true)
     })
 
+    test('should compile ts file which has an existing js file', () => {
+      const configSet = createConfigSet({
+        tsJestConfig: baseTsJestConfig,
+      })
+      const fileName = join(mockFolder, 'thing.ts')
+      const fileContent = readFileSync(fileName, 'utf-8')
+      configSet.parsedTsConfig.fileNames.push(...[fileName.replace('.ts', '.js'), fileName])
+      const compiler = new TsCompiler(configSet, new Map())
+
+      const compiledOutput = compiler.getCompiledOutput(fileContent, fileName, false)
+
+      expect(new ProcessedSource(compiledOutput, fileName).outputCodeWithoutMaps).toMatchSnapshot()
+    })
+
     describe('allowJs option', () => {
       const fileName = 'test-allow-js.js'
       const source = 'export default 42'
@@ -407,6 +423,7 @@ const t: string = f(5)
         const jestCacheFS = new Map<string, string>()
         const importedModule1 = join(mockFolder, 'thing1.ts')
         const importedModule2 = join(mockFolder, 'thing2.ts')
+        const importedModule3 = join(mockFolder, 'babel-foo.config.js')
         const fileContentWithModules = readFileSync(fileName, 'utf-8')
         jestCacheFS.set(importedModule1, readFileSync(importedModule1, 'utf-8'))
         const compiler = makeCompiler(
@@ -420,7 +437,7 @@ const t: string = f(5)
           compiler
             .getResolvedModules(fileContentWithModules, fileName, new Map())
             .map((resolvedFileName) => normalize(resolvedFileName)),
-        ).toEqual([importedModule1, importedModule2])
+        ).toEqual([importedModule3, importedModule1, importedModule2])
       })
     })
 

src/compiler/ts-compiler.ts

@@ -21,8 +21,8 @@ import type {
   ResolvedModuleWithFailedLookupLocations,
 } from 'typescript'
 
-import { ConfigSet, TS_JEST_OUT_DIR } from '../config/config-set'
-import { LINE_FEED } from '../constants'
+import type { ConfigSet } from '../config/config-set'
+import { LINE_FEED, TS_TSX_REGEX } from '../constants'
 import type { StringMap, TsCompilerInstance, TsJestAstTransformer, TTypeScript } from '../types'
 import { rootLogger } from '../utils/logger'
 import { Errors, interpolate } from '../utils/messages'
@@ -116,12 +116,7 @@ export class TsCompiler implements TsCompilerInstance {
   private _createLanguageService(): void {
     // Initialize memory cache for typescript compiler
     this._parsedTsConfig.fileNames
-      // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-      .filter(
-        (fileName) =>
-          !this.configSet.isTestFile(fileName) &&
-          !fileName.includes(this._parsedTsConfig.options.outDir ?? TS_JEST_OUT_DIR),
-      )
+      .filter((fileName) => TS_TSX_REGEX.test(fileName) && !this.configSet.isTestFile(fileName))
       // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
       .forEach((fileName) => this._fileVersionCache!.set(fileName, 0))
     /* istanbul ignore next */