perf(babel): uses babel-jest cache key as part of ours

README.md

@@ -206,13 +206,13 @@ module.exports = {
 ### Using `babel-jest`
 By default ts-jest does not rely on babel-jest. But you may want to use some babel plugins and stll be able to write TypeScript. This can be achieved using the `babelJest` config key. It can be:
 
-- `true`, in which case it'll try to find a babel configuration file:
+- `true`, in which case it'll use defaults from babelrc or any other found config file:
   ```js
   // jest.config.js
   module.exports = {
     globals: {
       'ts-jest': {
-        babelConfig: true
+        babelJest: true
       }
     }
   };
@@ -224,7 +224,7 @@ By default ts-jest does not rely on babel-jest. But you may want to use some bab
   module.exports = {
     globals: {
       'ts-jest': {
-        babelConfig: 'babelrc.test.js'
+        babelJest: 'babelrc.test.js'
       }
     }
   };
@@ -236,7 +236,7 @@ By default ts-jest does not rely on babel-jest. But you may want to use some bab
   module.exports = {
     globals: {
       'ts-jest': {
-        babelConfig: {
+        babelJest: {
           plugins: [
             // ...
           ]
@@ -246,6 +246,18 @@ By default ts-jest does not rely on babel-jest. But you may want to use some bab
   };
   ```
 
+- `false`, in which case it'll disable the use of babel-jest (which is the default):
+  ```js
+  // jest.config.js
+  module.exports = {
+    globals: {
+      'ts-jest': {
+        babelJest: false
+      }
+    }
+  };
+  ```
+
 ### TS compiler & error reporting
 
 <center>=== TBD ===</center>

src/ts-jest-transformer.spec.ts

@@ -1,6 +1,5 @@
-import TsJestTransformer from './ts-jest-transformer';
+import TsJestTransformerOriginal from './ts-jest-transformer';
 import * as fakers from './__helpers__/fakers';
-import * as babelCfg from './utils/babel-config';
 import * as closesPkgJson from './utils/closest-package-json';
 import * as TsJestProgram from './ts-program';
 
@@ -9,28 +8,35 @@ jest.mock('./utils/closest-package-json');
 jest.mock('./utils/backports');
 
 const mocks = {
-  babelConfig: undefined as any,
+  babelJestCacheKey: undefined as any,
   set packageJson(val: any) {
     (closesPkgJson as any).__default = val;
   },
   set tsConfig(val: any) {
     (TsJestProgram as any).__tsConfig = val;
   },
   reset() {
-    this.babelConfig = undefined;
+    this.babelJestCacheKey = 'babel-jest-cache-key';
     this.packageJson = { name: 'mock' };
     this.tsConfig = {};
   },
 };
-beforeAll(() => {
-  jest
-    .spyOn(babelCfg, 'loadDefault')
-    .mockImplementation(() => mocks.babelConfig);
-});
 afterEach(() => {
   mocks.reset();
 });
 
+class TsJestTransformer extends TsJestTransformerOriginal {
+  babelJestFor(jestCfg: jest.ProjectConfig) {
+    const bj = super.babelJestFor(jestCfg);
+    if (bj && !(bj.getCacheKey as any).mock) {
+      jest
+        .spyOn(bj, 'getCacheKey')
+        .mockImplementation(() => mocks.babelJestCacheKey);
+    }
+    return bj;
+  }
+}
+
 describe('process', () => {
   describe('hoisting', () => {
     const transformer = new TsJestTransformer();
@@ -78,7 +84,10 @@ describe('getCacheKey', () => {
   const call: typeof TsJestTransformer['prototype']['getCacheKey'] = (
     // tslint:disable-next-line:trailing-comma
     ...args
-  ) => new TsJestTransformer().getCacheKey(...args);
+  ) => {
+    const tr = new TsJestTransformer();
+    return tr.getCacheKey(...args);
+  };
   const defaultCall = () => call(fakeSource, fakeFilePath, fakeJestConfig);
 
   it('should be a 28 chars string, different for each case', () => {
@@ -91,7 +100,7 @@ describe('getCacheKey', () => {
       call(fakeSource, fakeFilePath, fakeJestConfig, { rootDir: '/child' }),
     ];
 
-    mocks.babelConfig = '{sourceMaps: true}';
+    mocks.babelJestCacheKey = 'another-babel-jest-cache-key';
     allCacheKeys.push(defaultCall());
     mocks.reset();
 

src/ts-jest-transformer.ts

@@ -3,6 +3,7 @@ import {
   TsJestConfig,
   BabelConfig,
   TsJestHooksMap,
+  BabelJestTransformer,
 } from './types';
 import TsProgram from './ts-program';
 import Memoize from './utils/memoize';
@@ -11,7 +12,6 @@ import { backportJestConfig } from './utils/backports';
 import jestRootDir from './utils/jest-root-dir';
 import { sep, resolve } from 'path';
 import parseJsonUnsafe from './utils/parse-json-unsafe';
-import * as babelCfg from './utils/babel-config';
 import closestPatckageJson from './utils/closest-package-json';
 import sha1 from './utils/sha1';
 import importer from './utils/importer';
@@ -42,25 +42,28 @@ export default class TsJestTransformer implements jest.Transformer {
   }
 
   @Memoize(jestRootDir)
-  babelJestFor(jestConfig: jest.ProjectConfig): jest.Transformer {
+  babelJestFor(
+    jestConfig: jest.ProjectConfig,
+  ): BabelJestTransformer | undefined {
+    const babelJestConfig = this.babelJestConfigFor(jestConfig);
+    if (!babelJestConfig) {
+      return;
+    }
     return importer
       .babelJest(ImportReasons.babelJest)
-      .createTransformer(this.babelConfigFor(jestConfig));
+      .createTransformer(babelJestConfig) as BabelJestTransformer;
   }
 
   @Memoize(jestRootDir)
-  babelConfigFor(jestConfig: jest.ProjectConfig): BabelConfig | undefined {
+  babelJestConfigFor(jestConfig: jest.ProjectConfig): BabelConfig | undefined {
     const config = this.configFor(jestConfig);
     const rootDir = jestRootDir(jestConfig);
     if (config.babelJest === false) {
       return;
     }
 
     let babelConfig!: BabelConfig;
-    if (config.babelJest === true) {
-      // lookup babelrc file
-      babelConfig = babelCfg.extend({}, babelCfg.loadDefault(rootDir));
-    } else if (typeof config.babelJest === 'string') {
+    if (typeof config.babelJest === 'string') {
       // path to a babelrc file
       let filePath = config.babelJest.replace('<rootDir>', `${rootDir}${sep}`);
       filePath = resolve(rootDir, filePath);
@@ -70,8 +73,7 @@ export default class TsJestTransformer implements jest.Transformer {
       babelConfig = config.babelJest;
     }
 
-    // ensure to return a freezed copy object
-    return babelCfg.freeze(babelCfg.extend({}, babelConfig));
+    return babelConfig;
   }
 
   @Memoize(jestRootDir)
@@ -99,6 +101,11 @@ export default class TsJestTransformer implements jest.Transformer {
       stringifyRegEx = undefined;
     }
 
+    // babelJest true => {}
+    if (options.babelJest === true) {
+      options.babelJest = {};
+    }
+
     // parsed options
     return {
       inputOptions: options,
@@ -126,7 +133,7 @@ export default class TsJestTransformer implements jest.Transformer {
     const stringify =
       config.stringifyContentPathRegex &&
       config.stringifyContentPathRegex.test(filePath);
-    const useBabelJest = !stringify && config.babelJest;
+    const babelJest = !stringify && this.babelJestFor(jestConfig);
 
     // get the tranformer instance
     const program = this.programFor(jestConfig);
@@ -142,8 +149,8 @@ export default class TsJestTransformer implements jest.Transformer {
     result = program.transpileModule(filePath, source, instrument);
 
     // calling babel-jest transformer
-    if (useBabelJest) {
-      result = this.babelJestFor(jestConfig).process(
+    if (babelJest) {
+      result = babelJest.process(
         result,
         filePath,
         jestConfig,
@@ -170,11 +177,10 @@ export default class TsJestTransformer implements jest.Transformer {
     fileContent: string,
     filePath: string,
     jestConfigStr: string,
-    {
-      instrument = false,
-      rootDir,
-    }: { instrument?: boolean; rootDir?: string } = {},
+    transformOptions: { instrument?: boolean; rootDir?: string } = {},
   ): string {
+    // tslint:disable-next-line:prefer-const
+    let { instrument = false, rootDir } = transformOptions;
     const CHAR0 = '\0';
     // will be used as the hashing data source
     const hashData: string[] = [];
@@ -192,14 +198,24 @@ export default class TsJestTransformer implements jest.Transformer {
     const sanitizedJestConfig: jest.ProjectConfig = this.sanitizedJestConfigFor(
       jestConfig,
     );
+
     // add jest config
     hashUpdate(JSON.stringify(sanitizedJestConfig));
     // add project's package.json
     const projectPkg = closestPatckageJson(rootDir, true);
     hashUpdate(projectPkg);
-    // add babel config if using babel jest
-    const babelConfig = this.babelConfigFor(jestConfig) || {};
-    hashUpdate(JSON.stringify(babelConfig));
+    // if using babel jest, adds its cacheKey as well
+    const babelJest = this.babelJestFor(jestConfig);
+    if (babelJest) {
+      hashUpdate(
+        babelJest.getCacheKey(
+          fileContent,
+          filePath,
+          jestConfigStr,
+          transformOptions as any,
+        ),
+      );
+    }
     // add tsconfig
     const tsConfig = this.programFor(sanitizedJestConfig).parsedConfig;
     hashUpdate(JSON.stringify(tsConfig));

src/types.ts

@@ -7,6 +7,12 @@ export type TBabelCore = typeof _babel;
 export type TPackageJson = IPackageJSON;
 export type TClosestFileData = typeof _closestFileData;
 export type TBabelJest = Required<jest.Transformer>;
+export type BabelJestTransformer = {
+  [K in Exclude<keyof jest.Transformer, 'createTransformer'>]: Exclude<
+    jest.Transformer[K],
+    undefined
+  >
+};
 
 // CAUTION: use same key-value pair allow us to not store a list of values somewhere
 export enum DiagnosticTypes {
@@ -53,7 +59,7 @@ export interface TsJestGlobalOptions {
 
 export interface TsJestConfig {
   inputOptions: TsJestGlobalOptions;
-  babelJest: BabelConfig | string | boolean;
+  babelJest: BabelConfig | string | false;
   diagnostics: DiagnosticTypes[];
 
   // to deprecate / deprecated === === ===