chore: add babel plugin to make sure Jest is unaffected by fake Promise implementations

CHANGELOG.md

@@ -80,6 +80,7 @@
 - `[jest-test-typescript-parser]` Remove from the repository ([#7232](https://github.com/facebook/jest/pull/7232))
 - `[tests]` Free tests from the dependency on value of FORCE_COLOR ([#6585](https://github.com/facebook/jest/pull/6585/files))
 - `[jest-diff]` Standardize filenames ([#7238](https://github.com/facebook/jest/pull/7238))
+- `[*]` Add babel plugin to make sure Jest is unaffected by fake Promise implementations ([#7225](https://github.com/facebook/jest/pull/7225))
 
 ### Performance
 

packages/jest-circus/src/legacy_code_todo_rewrite/jest_adapter_init.js

@@ -7,9 +7,9 @@
  * @flow
  */
 
-import type {TestResult, Status} from 'types/TestResult';
+import type {AssertionResult, TestResult, Status} from 'types/TestResult';
 import type {GlobalConfig, Path, ProjectConfig} from 'types/Config';
-import type {Event, TestEntry} from 'types/Circus';
+import type {Event, RunResult, TestEntry} from 'types/Circus';
 
 import {extractExpectedAssertionsErrors, getState, setState} from 'expect';
 import {formatExecError, formatResultsErrors} from 'jest-message-util';
@@ -19,12 +19,11 @@ import {
   buildSnapshotResolver,
 } from 'jest-snapshot';
 import {addEventHandler, dispatch, ROOT_DESCRIBE_BLOCK_NAME} from '../state';
-import {getTestID, getOriginalPromise} from '../utils';
+import {getTestID} from '../utils';
 import run from '../run';
 // eslint-disable-next-line import/default
 import globals from '../index';
 
-const Promise = getOriginalPromise();
 export const initialize = ({
   config,
   getPrettier,
@@ -123,46 +122,48 @@ export const runAndTransformResultsToJestFormat = async ({
   globalConfig: GlobalConfig,
   testPath: string,
 }): Promise<TestResult> => {
-  const runResult = await run();
+  const runResult: RunResult = await run();
 
   let numFailingTests = 0;
   let numPassingTests = 0;
   let numPendingTests = 0;
   let numTodoTests = 0;
 
-  const assertionResults = runResult.testResults.map(testResult => {
-    let status: Status;
-    if (testResult.status === 'skip') {
-      status = 'pending';
-      numPendingTests += 1;
-    } else if (testResult.status === 'todo') {
-      status = 'todo';
-      numTodoTests += 1;
-    } else if (testResult.errors.length) {
-      status = 'failed';
-      numFailingTests += 1;
-    } else {
-      status = 'passed';
-      numPassingTests += 1;
-    }
-
-    const ancestorTitles = testResult.testPath.filter(
-      name => name !== ROOT_DESCRIBE_BLOCK_NAME,
-    );
-    const title = ancestorTitles.pop();
-
-    return {
-      ancestorTitles,
-      duration: testResult.duration,
-      failureMessages: testResult.errors,
-      fullName: ancestorTitles.concat(title).join(' '),
-      invocations: testResult.invocations,
-      location: testResult.location,
-      numPassingAsserts: 0,
-      status,
-      title: testResult.testPath[testResult.testPath.length - 1],
-    };
-  });
+  const assertionResults: Array<AssertionResult> = runResult.testResults.map(
+    testResult => {
+      let status: Status;
+      if (testResult.status === 'skip') {
+        status = 'pending';
+        numPendingTests += 1;
+      } else if (testResult.status === 'todo') {
+        status = 'todo';
+        numTodoTests += 1;
+      } else if (testResult.errors.length) {
+        status = 'failed';
+        numFailingTests += 1;
+      } else {
+        status = 'passed';
+        numPassingTests += 1;
+      }
+
+      const ancestorTitles = testResult.testPath.filter(
+        name => name !== ROOT_DESCRIBE_BLOCK_NAME,
+      );
+      const title = ancestorTitles.pop();
+
+      return {
+        ancestorTitles,
+        duration: testResult.duration,
+        failureMessages: testResult.errors,
+        fullName: ancestorTitles.concat(title).join(' '),
+        invocations: testResult.invocations,
+        location: testResult.location,
+        numPassingAsserts: 0,
+        status,
+        title: testResult.testPath[testResult.testPath.length - 1],
+      };
+    },
+  );
 
   let failureMessage = formatResultsErrors(
     assertionResults,

packages/jest-circus/src/run.js

@@ -23,11 +23,8 @@ import {
   getTestID,
   invariant,
   makeRunResult,
-  getOriginalPromise,
 } from './utils';
 
-const Promise = getOriginalPromise();
-
 const run = async (): Promise<RunResult> => {
   const {rootDescribeBlock} = getState();
   dispatch({name: 'run_start'});

packages/jest-circus/src/utils.js

@@ -32,12 +32,6 @@ import prettyFormat from 'pretty-format';
 
 import {getState} from './state';
 
-// Try getting the real promise object from the context, if available. Someone
-// could have overridden it in a test. Async functions return it implicitly.
-// eslint-disable-next-line no-unused-vars
-const Promise = global[Symbol.for('jest-native-promise')] || global.Promise;
-export const getOriginalPromise = () => Promise;
-
 const stackUtils = new StackUtils({cwd: 'A path that does not exist'});
 
 export const makeDescribe = (

packages/jest-jasmine2/src/jasmine/Env.js

@@ -37,11 +37,6 @@ import checkIsError from '../is_error';
 import assertionErrorMessage from '../assert_support';
 import {ErrorWithStack} from 'jest-util';
 
-// Try getting the real promise object from the context, if available. Someone
-// could have overridden it in a test. Async functions return it implicitly.
-// eslint-disable-next-line no-unused-vars
-const Promise = global[Symbol.for('jest-native-promise')] || global.Promise;
-
 export default function(j$) {
   function Env(options) {
     options = options || {};

packages/jest-jasmine2/src/p_cancelable.js

@@ -2,10 +2,6 @@
 
 'use strict';
 
-// Try getting the real promise object from the context, if available. Someone
-// could have overridden it in a test.
-const Promise = global[Symbol.for('jest-native-promise')] || global.Promise;
-
 class CancelError extends Error {
   constructor() {
     super('Promise was canceled');

packages/jest-jasmine2/src/p_timeout.js

@@ -7,10 +7,6 @@
  * @flow
  */
 
-// Try getting the real promise object from the context, if available. Someone
-// could have overridden it in a test.
-const Promise = global[Symbol.for('jest-native-promise')] || global.Promise;
-
 // A specialized version of `p-timeout` that does not touch globals.
 // It does not throw on timeout.
 export default function pTimeout(

packages/jest-jasmine2/src/queue_runner.js

@@ -7,11 +7,6 @@
  * @flow
  */
 
-// Try getting the real promise object from the context, if available. Someone
-// could have overridden it in a test.
-const Promise: Class<Promise> =
-  global[Symbol.for('jest-native-promise')] || global.Promise;
-
 import PCancelable from './p_cancelable';
 import pTimeout from './p_timeout';
 
@@ -27,14 +22,15 @@ type Options = {
 type QueueableFn = {
   fn: (next: () => void) => void,
   timeout?: () => number,
+  initError?: Error,
 };
 
 export default function queueRunner(options: Options) {
   const token = new PCancelable((onCancel, resolve) => {
     onCancel(resolve);
   });
 
-  const mapper = ({fn, timeout, initError = new Error()}) => {
+  const mapper = ({fn, timeout, initError = new Error()}: QueueableFn) => {
     let promise = new Promise(resolve => {
       const next = function(err) {
         if (err) {

packages/jest-jasmine2/src/reporter.js

@@ -16,10 +16,6 @@ import type {
   TestResult,
 } from 'types/TestResult';
 
-// Try getting the real promise object from the context, if available. Someone
-// could have overridden it in a test.
-const Promise = global[Symbol.for('jest-native-promise')] || global.Promise;
-
 import {formatResultsErrors} from 'jest-message-util';
 
 type Suite = {

packages/jest-jasmine2/src/tree_processor.js

@@ -26,11 +26,6 @@ type TreeNode = {
   children?: Array<TreeNode>,
 };
 
-// Try getting the real promise object from the context, if available. Someone
-// could have overridden it in a test. Async functions return it implicitly.
-// eslint-disable-next-line no-unused-vars
-const Promise = global[Symbol.for('jest-native-promise')] || global.Promise;
-
 export default function treeProcessor(options: Options) {
   const {
     nodeComplete,

scripts/babel-plugin-jest-native-promise.js

@@ -0,0 +1,31 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc. 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.
+ */
+
+'use strict';
+
+// This plugin exists to make sure that we use a `Promise` that has not been messed with by user code.
+// Might consider extending this to other globals as well in the future
+
+module.exports = ({template}) => {
+  const promiseDeclaration = template(`
+    var Promise = global[Symbol.for('jest-native-promise')] || global.Promise;
+  `);
+
+  return {
+    name: 'jest-native-promise',
+    visitor: {
+      ReferencedIdentifier(path, state) {
+        if (path.node.name === 'Promise' && !state.injectedPromise) {
+          state.injectedPromise = true;
+          path
+            .findParent(p => p.isProgram())
+            .unshiftContainer('body', promiseDeclaration());
+        }
+      },
+    },
+  };
+};

scripts/build.js

@@ -150,7 +150,13 @@ function buildFile(file, silent) {
     const options = Object.assign({}, transformOptions);
     options.plugins = options.plugins.slice();
 
-    if (!INLINE_REQUIRE_BLACKLIST.test(file)) {
+    if (INLINE_REQUIRE_BLACKLIST.test(file)) {
+      // The modules in the blacklist are injected into the user's sandbox
+      // We need to guard `Promise` there.
+      options.plugins.push(
+        require.resolve('./babel-plugin-jest-native-promise')
+      );
+    } else {
       // Remove normal plugin.
       options.plugins = options.plugins.filter(
         plugin =>

types/Circus.js

@@ -9,7 +9,7 @@
 
 export type DoneFn = (reason?: string | Error) => void;
 export type BlockFn = () => void;
-export type BlockName = string | Function;
+export type BlockName = string;
 export type BlockMode = void | 'skip' | 'only' | 'todo';
 export type TestMode = BlockMode;
 export type TestName = string;
@@ -153,6 +153,7 @@ export type TestStatus = 'skip' | 'done' | 'todo';
 export type TestResult = {|
   duration: ?number,
   errors: Array<FormattedError>,
+  invocations: number,
   status: TestStatus,
   location: ?{|column: number, line: number|},
   testPath: Array<TestName | BlockName>,

types/TestResult.js

@@ -98,6 +98,7 @@ export type AssertionResult = {|
   duration?: ?Milliseconds,
   failureMessages: Array<string>,
   fullName: string,
+  invocations?: number,
   location: ?Callsite,
   numPassingAsserts: number,
   status: Status,