fix: do not inject global var into module wrapper

CHANGELOG.md

@@ -7,6 +7,7 @@
 ### Fixes
 
 - `[jest-runtime]` `require.main` is no longer `undefined` when using `jest.resetModules` ([#10626](https://github.com/facebook/jest/pull/10626))
+- `[jest-runtime]` Do not inject `global` variable into module wrapper ([#10644](https://github.com/facebook/jest/pull/10644))
 - `[@jest/types]` Add missing values for `timers` ([#10632](https://github.com/facebook/jest/pull/10632))
 
 ### Chore & Maintenance

e2e/__tests__/global-mutation.test.ts

@@ -0,0 +1,12 @@
+/**
+ * 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.
+ */
+
+const global = 'woo!';
+
+test('can redefine global', () => {
+  expect(global).toBe('woo!');
+});

packages/jest-environment/src/index.ts

@@ -29,7 +29,6 @@ export type ModuleWrapper = (
   require: Module['require'],
   __dirname: string,
   __filename: Module['filename'],
-  global: Global.Global,
   jest?: Jest,
   ...extraGlobals: Array<Global.Global[keyof Global.Global]>
 ) => unknown;

packages/jest-runtime/src/index.ts

@@ -366,7 +366,7 @@ class Runtime {
       invariant(context);
 
       if (this._resolver.isCoreModule(modulePath)) {
-        const core = await this._importCoreModule(modulePath, context);
+        const core = this._importCoreModule(modulePath, context);
         this._esmoduleRegistry.set(cacheKey, core);
         return core;
       }
@@ -1078,7 +1078,6 @@ class Runtime {
         module.require, // require implementation
         module.path, // __dirname
         module.filename, // __filename
-        this._environment.global, // global object
         ...lastArgs.filter(notEmpty),
       );
     } catch (error) {
@@ -1632,7 +1631,6 @@ class Runtime {
       'require',
       '__dirname',
       '__filename',
-      'global',
       this._config.injectGlobals ? 'jest' : undefined,
       ...this._config.extraGlobals,
     ].filter(notEmpty);