feat: pass ESM options to tarnsformers

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ### Features
 
+- `[@jest/transformer]`: Support passing `supportsDynamicImport` and `supportsStaticESM` ([#9597](https://github.com/facebook/jest/pull/9597))
+
 ### Fixes
 
 ### Chore & Maintenance

e2e/__tests__/__snapshots__/transform.test.ts.snap

@@ -6,7 +6,7 @@ FAIL __tests__/ignoredFile.test.js
 
     babel-jest: Babel ignores __tests__/ignoredFile.test.js - make sure to include the file in Jest's transformIgnorePatterns as well.
 
-      at loadBabelConfig (../../../packages/babel-jest/build/index.js:191:13)
+      at loadBabelConfig (../../../packages/babel-jest/build/index.js:212:13)
 `;
 
 exports[`babel-jest instruments only specific files and collects coverage 1`] = `

packages/babel-jest/package.json

@@ -20,7 +20,7 @@
   "dependencies": {
     "@jest/transform": "^25.2.6",
     "@jest/types": "^25.2.6",
-    "@types/babel__core": "^7.1.0",
+    "@types/babel__core": "^7.1.7",
     "babel-plugin-istanbul": "^6.0.0",
     "babel-preset-jest": "^25.2.6",
     "chalk": "^3.0.0",

packages/babel-jest/src/__tests__/index.ts

@@ -5,9 +5,18 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import babelJest from '../index';
+import babelJest = require('../index');
+import {loadPartialConfig} from '../loadBabelConfig';
 import {makeProjectConfig} from '../../../../TestUtils';
 
+jest.mock('../loadBabelConfig', () => {
+  const actual = jest.requireActual('@babel/core');
+
+  return {
+    loadPartialConfig: jest.fn((...args) => actual.loadPartialConfig(...args)),
+  };
+});
+
 //Mock data for all the tests
 const sourceString = `
 const sum = (a, b) => a+b;
@@ -21,7 +30,11 @@ const customMultiply = (obj, mul) => {
 customMultiply({a: 32, dummy: "test"}, 2);
 `;
 
-test(`Returns source string with inline maps when no transformOptions is passed`, () => {
+beforeEach(() => {
+  jest.clearAllMocks();
+});
+
+test('Returns source string with inline maps when no transformOptions is passed', () => {
   const result = babelJest.process(
     sourceString,
     'dummy_path.js',
@@ -32,6 +45,55 @@ test(`Returns source string with inline maps when no transformOptions is passed`
   expect(result.map).toBeDefined();
   expect(result.code).toMatch('//# sourceMappingURL');
   expect(result.code).toMatch('customMultiply');
-  expect(result.map.sources).toEqual(['dummy_path.js']);
-  expect(JSON.stringify(result.map.sourcesContent)).toMatch('customMultiply');
+  expect(result.map!.sources).toEqual(['dummy_path.js']);
+  expect(JSON.stringify(result.map!.sourcesContent)).toMatch('customMultiply');
+});
+
+describe('caller option correctly merges from defaults and options', () => {
+  test.each([
+    [
+      {
+        supportsDynamicImport: true,
+        supportsStaticESM: true,
+      },
+      {
+        supportsDynamicImport: true,
+        supportsStaticESM: true,
+      },
+    ],
+    [
+      {
+        supportsDynamicImport: false,
+        supportsStaticESM: false,
+      },
+      {
+        supportsDynamicImport: false,
+        supportsStaticESM: false,
+      },
+    ],
+    [
+      {supportsStaticESM: false},
+      {
+        supportsDynamicImport: false,
+        supportsStaticESM: false,
+      },
+    ],
+    [
+      {supportsDynamicImport: true},
+      {
+        supportsDynamicImport: true,
+        supportsStaticESM: false,
+      },
+    ],
+  ])('%j -> %j', (input, output) => {
+    babelJest.process(sourceString, 'dummy_path.js', makeProjectConfig(), {
+      instrument: false,
+      ...input,
+    });
+
+    expect(loadPartialConfig).toHaveBeenCalledTimes(1);
+    expect(loadPartialConfig).toHaveBeenCalledWith(
+      expect.objectContaining({caller: {name: 'babel-jest', ...output}}),
+    );
+  });
 });

packages/babel-jest/src/index.ts

@@ -14,8 +14,8 @@ import {
   PartialConfig,
   TransformOptions,
   transformSync as babelTransform,
-  loadPartialConfig,
 } from '@babel/core';
+import {loadPartialConfig} from './loadBabelConfig';
 import chalk = require('chalk');
 import slash = require('slash');
 
@@ -34,7 +34,9 @@ const createTransformer = (
   options = {
     ...options,
     caller: {
+      ...options.caller,
       name: 'babel-jest',
+      supportsDynamicImport: false,
       supportsStaticESM: false,
     },
     compact: false,
@@ -46,9 +48,23 @@ const createTransformer = (
   function loadBabelConfig(
     cwd: Config.Path,
     filename: Config.Path,
+    supportsDynamicImport?: boolean,
+    supportsStaticESM?: boolean,
   ): PartialConfig {
     // `cwd` first to allow incoming options to override it
-    const babelConfig = loadPartialConfig({cwd, ...options, filename});
+    const babelConfig = loadPartialConfig({
+      cwd,
+      ...options,
+      caller: {
+        ...options.caller,
+        name: 'babel-jest',
+        supportsDynamicImport:
+          supportsDynamicImport ?? options.caller!.supportsDynamicImport,
+        supportsStaticESM:
+          supportsStaticESM ?? options.caller!.supportsStaticESM,
+      },
+      filename,
+    });
 
     if (!babelConfig) {
       throw new Error(
@@ -69,9 +85,14 @@ const createTransformer = (
       fileData,
       filename,
       configString,
-      {config, instrument, rootDir},
+      {config, instrument, rootDir, supportsDynamicImport, supportsStaticESM},
     ) {
-      const babelOptions = loadBabelConfig(config.cwd, filename);
+      const babelOptions = loadBabelConfig(
+        config.cwd,
+        filename,
+        supportsDynamicImport,
+        supportsStaticESM,
+      );
       const configPath = [
         babelOptions.config || '',
         babelOptions.babelrc || '',
@@ -98,7 +119,14 @@ const createTransformer = (
         .digest('hex');
     },
     process(src, filename, config, transformOptions) {
-      const babelOptions = {...loadBabelConfig(config.cwd, filename).options};
+      const babelOptions = {
+        ...loadBabelConfig(
+          config.cwd,
+          filename,
+          transformOptions?.supportsDynamicImport,
+          transformOptions?.supportsStaticESM,
+        ).options,
+      };
 
       if (transformOptions && transformOptions.instrument) {
         babelOptions.auxiliaryCommentBefore = ' istanbul ignore next ';

packages/babel-jest/src/loadBabelConfig.ts

@@ -0,0 +1,9 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+// this is a separate file so it can be mocked in tests
+export {loadPartialConfig} from '@babel/core';

packages/jest-runtime/src/index.ts

@@ -497,11 +497,9 @@ class Runtime {
   ): TransformationOptions {
     return {
       ...options,
-      changedFiles: this._coverageOptions.changedFiles,
-      collectCoverage: this._coverageOptions.collectCoverage,
-      collectCoverageFrom: this._coverageOptions.collectCoverageFrom,
-      collectCoverageOnlyFrom: this._coverageOptions.collectCoverageOnlyFrom,
-      coverageProvider: this._coverageOptions.coverageProvider,
+      ...this._coverageOptions,
+      supportsDynamicImport: false,
+      supportsStaticESM: false,
     };
   }
 
@@ -778,6 +776,8 @@ class Runtime {
       filename,
       this._getFullTransformationOptions(options),
       this._cacheFS[filename],
+      false,
+      false,
     );
 
     // we only care about non-internal modules

packages/jest-runtime/tsconfig.json

@@ -17,6 +17,7 @@
     {"path": "../jest-snapshot"},
     {"path": "../jest-source-map"},
     {"path": "../jest-test-result"},
+    {"path": "../jest-transform"},
     {"path": "../jest-types"},
     {"path": "../jest-util"},
     {"path": "../jest-validate"},