add noJestGlobals config, if false, no jest-circus globals

packages/jest-circus/src/index.ts

@@ -12,6 +12,8 @@ import {ErrorWithStack, isPromise} from 'jest-util';
 import {Circus, Global} from '@jest/types';
 import {dispatch} from './state';
 
+import expect = require('expect');
+
 type THook = (fn: Circus.HookFn, timeout?: number) => void;
 type DescribeFn = (
   blockName: Circus.BlockName,
@@ -199,17 +201,43 @@ const test: Global.It = (() => {
   return test;
 })();
 
-const it: Global.It = test;
+const it = test;
+
+const fdescribe = describe.only;
+const fit = it.only;
+const xit = it.skip;
+const xdescribe = describe.skip;
+const xtest = it.skip;
 
 export type Event = Circus.Event;
 export type State = Circus.State;
-export {afterAll, afterEach, beforeAll, beforeEach, describe, it, test};
+export {
+  afterAll,
+  afterEach,
+  beforeAll,
+  beforeEach,
+  describe,
+  expect,
+  fdescribe,
+  fit,
+  it,
+  test,
+  xdescribe,
+  xit,
+  xtest,
+};
 export default {
   afterAll,
   afterEach,
   beforeAll,
   beforeEach,
   describe,
+  expect,
+  fdescribe,
+  fit,
   it,
   test,
+  xdescribe,
+  xit,
+  xtest,
 };

packages/jest-circus/src/legacy-code-todo-rewrite/jestAdapter.ts

@@ -30,6 +30,7 @@ const jestAdapter = async (
     .requireInternalModule(path.resolve(__dirname, './jestExpect.js'))
     .default({
       expand: globalConfig.expand,
+      noJestGlobals: !globalConfig.noJestGlobals && !config.noJestGlobals,
     });
 
   const getPrettier = () =>

packages/jest-circus/src/legacy-code-todo-rewrite/jestAdapterInit.ts

@@ -53,22 +53,18 @@ export const initialize = ({
   testPath: Config.Path;
   parentProcess: Process;
 }) => {
+  if (!globalConfig.noJestGlobals && !config.noJestGlobals) {
+    const nodeGlobal = global as Global.Global;
+    Object.assign(nodeGlobal, globals);
+  }
+
   if (globalConfig.testTimeout) {
     getRunnerState().testTimeout = globalConfig.testTimeout;
   }
 
   const mutex = throat(globalConfig.maxConcurrency);
 
-  const nodeGlobal = global as Global.Global;
-  Object.assign(nodeGlobal, globals);
-
-  nodeGlobal.xit = nodeGlobal.it.skip;
-  nodeGlobal.xtest = nodeGlobal.it.skip;
-  nodeGlobal.xdescribe = nodeGlobal.describe.skip;
-  nodeGlobal.fit = nodeGlobal.it.only;
-  nodeGlobal.fdescribe = nodeGlobal.describe.only;
-
-  nodeGlobal.test.concurrent = (test => {
+  (globals.test as Global.ItConcurrent).concurrent = (test => {
     const concurrent = (
       testName: string,
       testFn: () => Promise<any>,
@@ -81,7 +77,7 @@ export const initialize = ({
       // that will result in this test to be skipped, so we'll be executing the promise function anyway,
       // even if it ends up being skipped.
       const promise = mutex(() => testFn());
-      nodeGlobal.test(testName, () => promise, timeout);
+      globals.test(testName, () => promise, timeout);
     };
 
     concurrent.only = (
@@ -97,7 +93,7 @@ export const initialize = ({
     concurrent.skip = test.skip;
 
     return concurrent;
-  })(nodeGlobal.test);
+  })(globals.test);
 
   addEventHandler(eventHandler);
 

packages/jest-circus/src/legacy-code-todo-rewrite/jestExpect.ts

@@ -15,8 +15,8 @@ import {
   toThrowErrorMatchingSnapshot,
 } from 'jest-snapshot';
 
-export default (config: {expand: boolean}) => {
-  global.expect = expect;
+export default (config: {expand: boolean; noJestGlobals: boolean}) => {
+  if (!config.noJestGlobals) global.expect = expect;
   expect.setState({
     expand: config.expand,
   });

packages/jest-types/src/Config.ts

@@ -257,6 +257,7 @@ export type GlobalConfig = {
   listTests: boolean;
   maxConcurrency: number;
   maxWorkers: number;
+  noJestGlobals?: boolean;
   noStackTrace: boolean;
   nonFlagArgs: Array<string>;
   noSCM?: boolean;
@@ -319,6 +320,7 @@ export type ProjectConfig = {
   modulePathIgnorePatterns: Array<string>;
   modulePaths?: Array<string>;
   name: string;
+  noJestGlobals?: boolean;
   prettierPath: string;
   resetMocks: boolean;
   resetModules: boolean;