fix: allow .mts to be processed (#3713)

Fixes #3702

src/constants.ts

@@ -1,10 +1,10 @@
 export const LINE_FEED = '\n'
 export const DECLARATION_TYPE_EXT = '.d.ts'
 export const JS_JSX_EXTENSIONS = ['.js', '.jsx']
-export const TS_TSX_REGEX = /\.tsx?$/
-export const JS_JSX_REGEX = /\.jsx?$/
-// `extensionsToTreatAsEsm` only accepts `.ts`, `.tsx` and `.jsx`. `.js`, `.cjs`, `.mjs` will throw error
-export const TS_EXT_TO_TREAT_AS_ESM = ['.ts', '.tsx']
+export const TS_TSX_REGEX = /\.m?tsx?$/
+export const JS_JSX_REGEX = /\.m?jsx?$/
+// `extensionsToTreatAsEsm` will throw error with `.mjs`
+export const TS_EXT_TO_TREAT_AS_ESM = ['.ts', '.tsx', '.mts']
 export const JS_EXT_TO_TREAT_AS_ESM = ['.jsx']
 /**
  * @internal

src/legacy/ts-jest-transformer.spec.ts

@@ -376,7 +376,7 @@ describe('TsJestTransformer', () => {
       expect(process.env.TS_JEST).toBe('1')
     })
 
-    test.each(['foo.ts', 'foo.tsx'])('should process ts/tsx file', (filePath) => {
+    test.each(['foo.ts', 'foo.tsx', 'foo.mts', 'foo.mtsx'])('should process ts/tsx file', (filePath) => {
       const fileContent = 'const foo = 1'
       const output = 'var foo = 1'
       tr.getCacheKey(fileContent, filePath, baseTransformOptions)
@@ -391,30 +391,33 @@ describe('TsJestTransformer', () => {
       })
     })
 
-    test.each(['foo.js', 'foo.jsx'])('should process js/jsx file with allowJs true', (filePath) => {
-      const fileContent = 'const foo = 1'
-      const output = 'var foo = 1'
-      const transformOptions = {
-        ...baseTransformOptions,
-        config: {
-          ...baseTransformOptions.config,
-          globals: {
-            'ts-jest': { tsconfig: { allowJs: true } },
+    test.each(['foo.js', 'foo.jsx', 'foo.mjs', 'foo.mjsx'])(
+      'should process js/jsx file with allowJs true',
+      (filePath) => {
+        const fileContent = 'const foo = 1'
+        const output = 'var foo = 1'
+        const transformOptions = {
+          ...baseTransformOptions,
+          config: {
+            ...baseTransformOptions.config,
+            globals: {
+              'ts-jest': { tsconfig: { allowJs: true } },
+            },
           },
-        },
-      }
-      tr.getCacheKey(fileContent, filePath, transformOptions)
-      logTarget.clear()
-      jest.spyOn(TsJestCompiler.prototype, 'getCompiledOutput').mockReturnValueOnce({
-        code: output,
-      })
+        }
+        tr.getCacheKey(fileContent, filePath, transformOptions)
+        logTarget.clear()
+        jest.spyOn(TsJestCompiler.prototype, 'getCompiledOutput').mockReturnValueOnce({
+          code: output,
+        })
 
-      const result = tr.process(fileContent, filePath, transformOptions)
+        const result = tr.process(fileContent, filePath, transformOptions)
 
-      expect(result).toEqual({
-        code: output,
-      })
-    })
+        expect(result).toEqual({
+          code: output,
+        })
+      },
+    )
 
     test('should process file with unknown extension and show warning message without babel-jest', () => {
       const fileContent = 'foo'

src/presets/__snapshots__/create-jest-preset.spec.ts.snap

@@ -61,6 +61,7 @@ Object {
     ".jsx",
     ".ts",
     ".tsx",
+    ".mts",
   ],
   "moduleFileExtensions": Array [
     "bar",