Run code transforms over global{Setup,Teardown}

CHANGELOG.md

@@ -45,6 +45,7 @@
 - `[jest-config]` Allow % based configuration of `--max-workers` ([#7494](https://github.com/facebook/jest/pull/7494))
 - `[jest-runner]` Instantiate the test environment class with the current `testPath` ([#7442](https://github.com/facebook/jest/pull/7442))
 - `[jest-config]` Always resolve jest-environment-jsdom from jest-config ([#7476](https://github.com/facebook/jest/pull/7476))
+- `[jest-cli]` Run code transforms over `global{Setup,Teardown}` ([#7562](https://github.com/facebook/jest/pull/7562))
 
 ### Fixes
 

e2e/global-setup/babel.config.js

@@ -0,0 +1,5 @@
+// Copyright (c) 2014-present, Facebook, Inc. All rights reserved.
+
+module.exports = {
+  presets: ['@babel/preset-flow'],
+};

e2e/global-setup/setup.js

@@ -13,7 +13,8 @@ const path = require('path');
 const DIR = path.join(os.tmpdir(), 'jest-global-setup');
 
 module.exports = function() {
-  return new Promise((resolve, reject) => {
+  // This uses a flow annotation to show it can be transpiled
+  return new Promise((resolve, reject: any) => {
     mkdirp.sync(DIR);
     const fileId = crypto.randomBytes(20).toString('hex');
     fs.writeFileSync(path.join(DIR, fileId), 'setup');

packages/jest-cli/package.json

@@ -32,6 +32,8 @@
     "jest-worker": "^23.2.0",
     "micromatch": "^2.3.11",
     "node-notifier": "^5.2.1",
+    "p-each-series": "^1.0.0",
+    "pirates": "^4.0.0",
     "prompts": "^1.1.0",
     "realpath-native": "^1.0.0",
     "rimraf": "^2.5.4",

packages/jest-cli/src/runGlobalHook.js

@@ -6,9 +6,22 @@
  *
  * @flow
  */
+
 import type {GlobalConfig} from 'types/Config';
 import type {Test} from 'types/TestRunner';
 
+import {extname, resolve} from 'path';
+import pEachSeries from 'p-each-series';
+import {addHook} from 'pirates';
+import {ScriptTransformer} from 'jest-runtime';
+
+const inJestsSource = __dirname.includes('packages/jest-cli');
+let packagesRoot;
+
+if (inJestsSource) {
+  packagesRoot = resolve(__dirname, '../../');
+}
+
 export default ({
   allTests,
   globalConfig,
@@ -17,7 +30,7 @@ export default ({
   allTests: Array<Test>,
   globalConfig: GlobalConfig,
   moduleName: 'globalSetup' | 'globalTeardown',
-}): Promise<?(any[])> => {
+}): Promise<void> => {
   const globalModulePaths = new Set(
     allTests.map(test => test.context.config[moduleName]),
   );
@@ -27,24 +40,48 @@ export default ({
   }
 
   if (globalModulePaths.size > 0) {
-    return Promise.all(
-      Array.from(globalModulePaths).map(async modulePath => {
-        if (!modulePath) {
-          return null;
-        }
-
-        // $FlowFixMe
-        const globalModule = require(modulePath);
-
-        if (typeof globalModule !== 'function') {
-          throw new TypeError(
-            `${moduleName} file must export a function at ${modulePath}`,
-          );
-        }
-
-        return globalModule(globalConfig);
-      }),
-    );
+    return pEachSeries(Array.from(globalModulePaths), async modulePath => {
+      if (!modulePath) {
+        return;
+      }
+
+      const projectConfig =
+        allTests
+          .map(t => t.context.config)
+          .find(c => c[moduleName] === modulePath) ||
+        // Fallback to first one
+        allTests[0].context.config;
+
+      const transformer = new ScriptTransformer(projectConfig);
+
+      const revertHook = addHook(
+        (code, filename) =>
+          transformer.transformSource(filename, code, false).code || code,
+        {
+          exts: [extname(modulePath)],
+          matcher(filename) {
+            // `babel-jest` etc would normally be caught by `node_modules`, but not in Jest's own repo
+            if (inJestsSource && filename.includes(packagesRoot)) {
+              return false;
+            }
+            return transformer._shouldTransform(filename);
+          },
+        },
+      );
+
+      // $FlowFixMe
+      const globalModule = require(modulePath);
+
+      if (typeof globalModule !== 'function') {
+        throw new TypeError(
+          `${moduleName} file must export a function at ${modulePath}`,
+        );
+      }
+
+      await globalModule(globalConfig);
+
+      revertHook();
+    });
   }
 
   return Promise.resolve();

yarn.lock

@@ -9858,6 +9858,13 @@ p-defer@^1.0.0:
   resolved "https://registry.yarnpkg.com/p-defer/-/p-defer-1.0.0.tgz#9f6eb182f6c9aa8cd743004a7d4f96b196b0fb0c"
   integrity sha1-n26xgvbJqozXQwBKfU+WsZaw+ww=
 
+p-each-series@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/p-each-series/-/p-each-series-1.0.0.tgz#930f3d12dd1f50e7434457a22cd6f04ac6ad7f71"
+  integrity sha1-kw89Et0fUOdDRFeiLNbwSsatf3E=
+  dependencies:
+    p-reduce "^1.0.0"
+
 p-finally@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/p-finally/-/p-finally-1.0.0.tgz#3fbcfb15b899a44123b34b6dcc18b724336a2cae"