fix(config): improve emit skipped error message (#2358)

Closes #2350

e2e/__tests__/allow-js.test.ts

@@ -2,21 +2,20 @@ import { allPackageSetsWithPreset, allValidPackageSets } from '../__helpers__/te
 import { configureTestCase } from '../__helpers__/test-case'
 
 describe('using babel-jest for js files', () => {
-  const testCase = configureTestCase('allow-js/with-outDir', {
+  const testCase = configureTestCase('allow-js', {
     jestConfig: { testRegex: '(foo|bar)\\.spec\\.[jt]s$' },
   })
 
   testCase.runWithTemplates(allValidPackageSets, 0, (runTest, { testLabel }) => {
     it(testLabel, () => {
       const result = runTest()
       expect(result.status).toBe(0)
-      expect(result).toMatchSnapshot()
     })
   })
 })
 
-describe('using ts-jest for js files with outDir', () => {
-  const testCase = configureTestCase('allow-js/with-outDir', {
+describe('using ts-jest for js files', () => {
+  const testCase = configureTestCase('allow-js', {
     jestConfig: {
       preset: 'ts-jest/presets/js-with-ts',
       testRegex: 'esm\\.spec\\.[jt]s$',
@@ -27,24 +26,6 @@ describe('using ts-jest for js files with outDir', () => {
     it(testLabel, () => {
       const result = runTest()
       expect(result.status).toBe(0)
-      expect(result).toMatchSnapshot()
-    })
-  })
-})
-
-describe('using ts-jest for js files without outDir', () => {
-  const testCase = configureTestCase('allow-js/without-outDir', {
-    jestConfig: {
-      preset: 'ts-jest/presets/js-with-ts',
-      testRegex: 'esm\\.spec\\.[jt]s$',
-    },
-  })
-
-  testCase.runWithTemplates(allPackageSetsWithPreset, 0, (runTest, { testLabel }) => {
-    it(testLabel, () => {
-      const result = runTest()
-      expect(result.status).toBe(0)
-      expect(result).toMatchSnapshot()
     })
   })
 })

src/compiler/ts-compiler.spec.ts

@@ -7,7 +7,6 @@ import { createConfigSet, makeCompiler } from '../__helpers__/fakers'
 import { logTargetMock } from '../__helpers__/mocks'
 import { mockFolder } from '../__helpers__/path'
 import ProcessedSource from '../__helpers__/processed-source'
-import { TS_JEST_OUT_DIR } from '../config/config-set'
 
 import { TsCompiler } from './ts-compiler'
 
@@ -33,7 +32,7 @@ describe('TsCompiler', () => {
     test('should compile js file for allowJs true', () => {
       const fileName = 'foo.js'
       const compiler = makeCompiler({
-        tsJestConfig: { ...baseTsJestConfig, tsconfig: { allowJs: true, outDir: TS_JEST_OUT_DIR } },
+        tsJestConfig: { ...baseTsJestConfig, tsconfig: { allowJs: true } },
       })
       const source = 'export default 42'
 
@@ -189,7 +188,6 @@ const t: string = f(5)
           ...baseTsJestConfig,
           tsconfig: {
             allowJs: true,
-            outDir: TS_JEST_OUT_DIR,
           },
           astTransformers: {
             before: ['dummy-transformer'],

src/compiler/ts-compiler.ts

@@ -1,4 +1,4 @@
-import { basename, normalize, relative } from 'path'
+import { basename, normalize } from 'path'
 
 import { LogContexts, Logger, LogLevels } from 'bs-logger'
 import memoize from 'lodash/memoize'
@@ -201,7 +201,7 @@ export class TsCompiler implements TsCompilerInstance {
       this._doTypeChecking(fileName)
       /* istanbul ignore next (this should never happen but is kept for security) */
       if (output.emitSkipped) {
-        throw new TypeError(`${relative(this.configSet.cwd, fileName)}: Emit skipped for language service`)
+        throw new Error(interpolate(Errors.CannotCompile, { file: fileName }))
       }
       // Throw an error when requiring `.d.ts` files.
       if (!output.outputFiles.length) {

src/config/config-set.spec.ts

@@ -51,15 +51,12 @@ describe('parsedTsConfig', () => {
   })
 
   it('should override some options', () => {
-    expect(get({ tsconfig: { inlineSources: false } }).options).toMatchObject({
+    expect(get({ tsconfig: { inlineSources: false, outDir: 'build' } }).options).toMatchObject({
       inlineSources: true,
+      outDir: TS_JEST_OUT_DIR,
     })
   })
 
-  it('should include default outDir $$ts-jest$$ when allowJs is enabled and no outDir from config', () => {
-    expect(get({ tsconfig: { allowJs: true } }).options.outDir).toBe(TS_JEST_OUT_DIR)
-  })
-
   it('should be able to read extends', () => {
     const cs = createConfigSet({
       tsJestConfig: { tsconfig: 'tsconfig.build.json' },

src/config/config-set.ts

@@ -158,6 +158,8 @@ export class ConfigSet {
     // to clear out else it's buggy
     out: undefined,
     outFile: undefined,
+    // ensure that `LanguageService` won't pick up things from `build` folder which can lead to emit skipped error
+    outDir: TS_JEST_OUT_DIR,
     composite: undefined, // see https://github.com/TypeStrong/ts-node/pull/657/files
     declarationDir: undefined,
     declarationMap: undefined,
@@ -419,10 +421,6 @@ export class ConfigSet {
         finalOptions.allowSyntheticDefaultImports = true
       }
     }
-    // Make sure when allowJs is enabled, outDir is required to have when using allowJs: true
-    if (finalOptions.allowJs && !finalOptions.outDir) {
-      finalOptions.outDir = TS_JEST_OUT_DIR
-    }
 
     // ensure undefined are removed and other values are overridden
     for (const key of Object.keys(forcedOptions)) {

src/utils/messages.ts

@@ -17,6 +17,7 @@ export const enum Errors {
   GotUnknownFileTypeWithBabel = 'Got a unknown file type to compile (file: {{path}}). To fix this, in your Jest config change the `transform` key which value is `ts-jest` so that it does not match this kind of files anymore. If you still want Babel to process it, add another entry to the `transform` option with value `babel-jest` which key matches this type of files.',
   ConfigNoModuleInterop = 'If you have issues related to imports, you should consider setting `esModuleInterop` to `true` in your TypeScript configuration file (usually `tsconfig.json`). See https://blogs.msdn.microsoft.com/typescript/2018/01/31/announcing-typescript-2-7/#easier-ecmascript-module-interoperability for more information.',
   MismatchNodeTargetMapping = 'There is a mismatch between your NodeJs version {{nodeJsVer}} and your TypeScript target {{compilationTarget}}. This might lead to some unexpected errors when running tests with `ts-jest`. To fix this, you can check https://github.com/microsoft/TypeScript/wiki/Node-Target-Mapping',
+  CannotCompile = "Unable to process '{{file}}'. Please check your tsconfig.",
 }
 
 /**