@@ -64,7 +64,7 @@ describe('process', () => {
 typescript = { options: {} } as any
 })
 
-it('should process input without babel', () => {
+it('should process ts input without babel', () => {
 expect(process()).toBe(`ts:${INPUT}`)
 expect(config.shouldStringifyContent.mock.calls).toMatchInlineSnapshot(`
 Array [
@@ -83,7 +83,28 @@ Array [
 `)
 })
 
-it('should process input with babel', () => {
+it('should process js input without babel', () => {
+typescript.options.allowJs = true
+args[1] = '/foo/bar.js'
+expect(process()).toBe(`ts:${INPUT}`)
+expect(config.shouldStringifyContent.mock.calls).toMatchInlineSnapshot(`
+Array [
+Array [
+"/foo/bar.js",
+],
+]
+`)
+expect(config.tsCompiler.compile.mock.calls).toMatchInlineSnapshot(`
+Array [
+Array [
+"export default \\"foo\\"",
+"/foo/bar.js",
+],
+]
+`)
+})
+
+it('should process ts input with babel', () => {
 babel = { process: jest.fn(s => `babel:${s}`) }
 expect(process()).toBe(`babel:ts:${INPUT}`)
 expect(config.shouldStringifyContent.mock.calls).toMatchInlineSnapshot(`
@@ -115,6 +136,40 @@ Array [
 `)
 })
 
+it('should process js input with babel', () => {
+typescript.options.allowJs = true
+babel = { process: jest.fn(s => `babel:${s}`) }
+args[1] = '/foo/bar.js'
+expect(process()).toBe(`babel:ts:${INPUT}`)
+expect(config.shouldStringifyContent.mock.calls).toMatchInlineSnapshot(`
+Array [
+Array [
+"/foo/bar.js",
+],
+]
+`)
+expect(config.babelJestTransformer.process.mock.calls).toMatchInlineSnapshot(`
+Array [
+Array [
+"ts:export default \\"foo\\"",
+"/foo/bar.js",
+Object {},
+Object {
+"instrument": false,
+},
+],
+]
+`)
+expect(config.tsCompiler.compile.mock.calls).toMatchInlineSnapshot(`
+Array [
+Array [
+"export default \\"foo\\"",
+"/foo/bar.js",
+],
+]
+`)
+})
+
 it('should return stringified version of file', () => {
 config.shouldStringifyContent.mockImplementation(() => true)
 expect(process()).toMatchInlineSnapshot(`"module.exports=\\"export default \\\\\\"foo\\\\\\"\\""`)

@@ -111,7 +111,7 @@ export class TsJestTransformer implements jest.Transformer {
 // we've got a '.js' but the compiler option `allowJs` is not set or set to false
 this.logger.warn({ fileName: filePath }, interpolate(Errors.GotJsFileButAllowJsFalse, { path: filePath }))
 result = source
-} else if (isTsFile) {
+} else if (isJsFile || isTsFile) {
 // transpile TS code (source maps are included)
 result = configs.tsCompiler.compile(source, filePath)
 } else {