From 253d93de212a9c626bb4d48515976bde5227b155 Mon Sep 17 00:00:00 2001
From: pepe <pepe@DESKTOP-JT5G5K0>
Date: Tue, 27 Dec 2022 19:52:52 -0500
Subject: [PATCH] feat(jest-runtime): expose isTornDown variable

This commit adds a new feature to the Jest runtime package that exposes
the `isTornDown` variable as a way to check if the Jest environment has
been torn down programmatically. The `isTornDown` variable is a
read-only boolean that is set to `true` when the environment is torn
down and `false` otherwise.

The commit also adds documentation for the `isTornDown` variable to the
Jest runtime module.

Closes #13640
---
 CHANGELOG.md                                    |  6 ++++++
 packages/jest-environment/src/index.ts          |  9 +++++++++
 .../src/__tests__/runtime_jest_fn.js            | 17 +++++++++++++++++
 packages/jest-runtime/src/index.ts              |  1 +
 4 files changed, 33 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 07f7984aa970..c7d26944a8cc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,12 @@
 
 ### Performance
 
+## 29.3.2
+
+### Features
+
+- `[jest-runtime]` Expose `isEnvironmentTornDown` function ([#13698](https://github.com/facebook/jest/pull/13698))
+
 ## 29.3.1
 
 ### Fixes
diff --git a/packages/jest-environment/src/index.ts b/packages/jest-environment/src/index.ts
index df50111e37f5..9f35a77eea4f 100644
--- a/packages/jest-environment/src/index.ts
+++ b/packages/jest-environment/src/index.ts
@@ -172,6 +172,15 @@ export interface Jest {
    * local module state doesn't conflict between tests.
    */
   isolateModules(fn: () => void): Jest;
+  /**
+   * A flag that indicates whether the Jest environment has been torn down.
+   * @example
+   * if (jest.isEnvironmentTornDown()) {
+   *   // The Jest environment has been torn down, so stop doing work
+   *   return;
+   * }
+   */
+  isEnvironmentTornDown(): boolean;
   /**
    * Mocks a module with an auto-mocked version when it is being required.
    */
diff --git a/packages/jest-runtime/src/__tests__/runtime_jest_fn.js b/packages/jest-runtime/src/__tests__/runtime_jest_fn.js
index a85322f97644..f793f131c40f 100644
--- a/packages/jest-runtime/src/__tests__/runtime_jest_fn.js
+++ b/packages/jest-runtime/src/__tests__/runtime_jest_fn.js
@@ -66,4 +66,21 @@ describe('Runtime', () => {
       expect(mock2).not.toHaveBeenCalled();
     });
   });
+
+  describe('jest.isEnvironmentTornDown()', () => {
+    it('should be set to false when the environment is not torn down', async () => {
+      const runtime = await createRuntime(__filename);
+      const root = runtime.requireModule(runtime.__mockRootPath);
+      runtime['isTornDown'] = false;
+      expect(root.jest.isEnvironmentTornDown()).toBe(false);
+    });
+
+    it('should be set to true when the environment is torn down', async () => {
+      const runtime = await createRuntime(__filename);
+      const root = runtime.requireModule(runtime.__mockRootPath);
+      expect(root.jest.isEnvironmentTornDown()).toBe(false);
+      runtime.teardown();
+      expect(root.jest.isEnvironmentTornDown()).toBe(true);
+    });
+  });
 });
diff --git a/packages/jest-runtime/src/index.ts b/packages/jest-runtime/src/index.ts
index c278d77052c5..03a80ff3cf05 100644
--- a/packages/jest-runtime/src/index.ts
+++ b/packages/jest-runtime/src/index.ts
@@ -2224,6 +2224,7 @@ export default class Runtime {
         return this._globalConfig.seed;
       },
       getTimerCount: () => _getFakeTimers().getTimerCount(),
+      isEnvironmentTornDown: () => this.isTornDown,
       isMockFunction: this._moduleMocker.isMockFunction,
       isolateModules,
       mock,