feat: Allow testRunner to be configurable

CHANGELOG.md

@@ -6,6 +6,7 @@
 - `[jest-config]` [**BREAKING**] Set default display name color based on runner ([#8689](https://github.com/facebook/jest/pull/8689))
 - `[jest-diff]` Add options for colors and symbols ([#8841](https://github.com/facebook/jest/pull/8841))
 - `[@jest/test-result]` Create method to create empty `TestResult` ([#8867](https://github.com/facebook/jest/pull/8867))
+- `[jest-runner]` [**BREAKING**] Run transforms over `testRunnner` ([#8823](https://github.com/facebook/jest/pull/8823))
 
 ### Fixes
 

e2e/__tests__/transform.test.ts

@@ -185,3 +185,14 @@ describe('transformer-config', () => {
     expect(stdout).toMatchSnapshot();
   });
 });
+
+describe('transform-testrunner', () => {
+  const dir = path.resolve(__dirname, '../transform/transform-testrunner');
+
+  it('should transform testRunner', () => {
+    const {json, stderr} = runWithJson(dir, ['--no-cache']);
+    expect(stderr).toMatch(/PASS/);
+    expect(json.success).toBe(true);
+    expect(json.numPassedTests).toBe(1);
+  });
+});

e2e/babel-plugin-jest-hoist/package.json

@@ -7,6 +7,10 @@
   },
   "jest": {
     "automock": true,
-    "testEnvironment": "node"
+    "testEnvironment": "node",
+    "transformIgnorePatterns": [
+      "jest-jasmine2",
+      "jest-circus"
+    ]
   }
 }

e2e/coverage-transform-instrumented/package.json

@@ -4,6 +4,11 @@
     "transform": {
       "^.+\\.(js)$": "<rootDir>/preprocessor.js"
     },
+    "transformIgnorePatterns": [
+      "jest-jasmine2",
+      "jest-each",
+      "jest-circus"
+    ],
     "testRegex": "/__tests__/.*\\.(js)$",
     "testEnvironment": "node",
     "moduleFileExtensions": [

e2e/transform-linked-modules/package.json

@@ -4,7 +4,10 @@
     "transformIgnorePatterns": [
       "/node_modules/",
       "<rootDir>/__tests__",
-      "<rootDir>/ignored/"
+      "<rootDir>/ignored/",
+      "jest-jasmine2",
+      "jest-each",
+      "jest-circus"
     ],
     "transform": {
       "^.+\\.js$": "<rootDir>/preprocessor.js"

e2e/transform/babel-jest-ignored/babel.config.js

@@ -5,4 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-module.exports = {only: ['blablabla']};
+module.exports = {
+  only: ['blablabla', /jest-jasmine2/, /jest-circus/, /jest-each/],
+};

e2e/transform/multiple-transformers/package.json

@@ -5,6 +5,7 @@
       "^.+\\.js$": "<rootDir>/jsPreprocessor.js",
       "^.+\\.svg$": "<rootDir>/filePreprocessor.js"
     },
+    "transformIgnorePatterns": ["jest-jasmine2", "jest-circus"],
     "testEnvironment": "node"
   },
   "dependencies": {

e2e/transform/transform-testrunner/__tests__/add.test.js

@@ -0,0 +1,10 @@
+/**
+ * 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.
+ */
+
+it('should add two numbers', () => {
+  expect(1 + 1).toBe(2);
+});

e2e/transform/transform-testrunner/babel.config.js

@@ -0,0 +1,18 @@
+/**
+ * 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.
+ */
+
+module.exports = {
+  presets: [
+    ['@babel/preset-typescript'],
+    [
+      '@babel/preset-env',
+      {
+        targets: {node: 6},
+      },
+    ],
+  ],
+};

e2e/transform/transform-testrunner/package.json

@@ -0,0 +1,10 @@
+{
+  "jest": {
+    "rootDir": "./",
+    "testRunner": "<rootDir>/test-runner.ts"
+  },
+  "dependencies": {
+    "@babel/preset-env": "^7.0.0",
+    "@babel/preset-typescript": "^7.0.0"
+  }
+}

e2e/transform/transform-testrunner/test-runner.ts

@@ -0,0 +1,34 @@
+/**
+ * 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.
+ */
+import {Config} from '@jest/types';
+import {JestEnvironment} from '@jest/environment';
+import Runtime from 'jest-runtime';
+import {TestResult, createEmptyTestResult} from '@jest/test-result';
+
+export default async function testRunner(
+  globalConfig: Config.GlobalConfig,
+  config: Config.ProjectConfig,
+  environment: JestEnvironment,
+  runtime: Runtime,
+  testPath: string
+): Promise<TestResult> {
+  return {
+    ...createEmptyTestResult(),
+    numPassingTests: 1,
+    testFilePath: testPath,
+    testResults: [
+      {
+        ancestorTitles: [],
+        duration: 2,
+        failureMessages: [],
+        fullName: 'sample test',
+        status: 'passed',
+        title: 'sample test',
+      },
+    ],
+  } as TestResult;
+}

e2e/transform/transform-testrunner/tsconfig.json

@@ -0,0 +1,6 @@
+{
+  "compilerOptions": {
+    "esModuleInterop": true,
+    "module": "commonjs",
+  }
+}

packages/jest-runner/package.json

@@ -13,6 +13,7 @@
     "@jest/console": "^24.7.1",
     "@jest/environment": "^24.9.0",
     "@jest/test-result": "^24.9.0",
+    "@jest/transform": "^24.9.0",
     "@jest/types": "^24.9.0",
     "chalk": "^2.4.2",
     "exit": "^0.1.2",

packages/jest-runner/src/runTest.ts

@@ -17,6 +17,7 @@ import {
   getConsoleOutput,
 } from '@jest/console';
 import {JestEnvironment} from '@jest/environment';
+import {ScriptTransformer} from '@jest/transform';
 import RuntimeClass = require('jest-runtime');
 import * as fs from 'graceful-fs';
 import {ErrorWithStack, interopRequireDefault, setGlobal} from 'jest-util';
@@ -102,13 +103,17 @@ async function runTestInternal(
     });
   }
 
+  const transformer = new ScriptTransformer(config);
   const TestEnvironment: typeof JestEnvironment = interopRequireDefault(
     require(testEnvironment),
   ).default;
-  const testFramework: TestFramework =
-    process.env.JEST_CIRCUS === '1'
-      ? require('jest-circus/runner') // eslint-disable-line import/no-extraneous-dependencies
-      : require(config.testRunner);
+  const testFramework: TestFramework = interopRequireDefault(
+    transformer.requireAndTranspileModule(
+      process.env.JEST_CIRCUS === '1'
+        ? 'jest-circus/runner'
+        : config.testRunner,
+    ),
+  ).default;
   const Runtime: typeof RuntimeClass = config.moduleLoader
     ? require(config.moduleLoader)
     : require('jest-runtime');

packages/jest-runner/tsconfig.json

@@ -15,6 +15,7 @@
     {"path": "../jest-resolve"},
     {"path": "../jest-runtime"},
     {"path": "../jest-test-result"},
+    {"path": "../jest-transform"},
     {"path": "../jest-types"},
     {"path": "../jest-worker"},
     {"path": "../jest-util"}