fix: support userAgent option for jsdom environment (#11773)

nwalters512 · web-flow · commit 4f4062ba4d50 · 2021-08-23T09:59:30.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,7 @@
 
 ### Fixes
 
+- `[jest-environment-jsdom]` Add support for `userAgent` option ([#11773](https://github.com/facebook/jest/pull/11773))
 - `[jest-environment-node]` Add `Event` and `EventTarget` to node global environment. ([#11705](https://github.com/facebook/jest/issues/11705))
 - `[jest-mock]` Fix `spyOn` to use `Object.prototype.hasOwnProperty` [#11721](https://github.com/facebook/jest/pull/11721)
 - `[jest-resolver]` Add dependency on `jest-haste-map` [#11759](https://github.com/facebook/jest/pull/11759)
diff --git a/packages/jest-environment-jsdom/src/__tests__/jsdom_environment.test.ts b/packages/jest-environment-jsdom/src/__tests__/jsdom_environment.test.ts
@@ -27,4 +27,16 @@ describe('JSDomEnvironment', () => {
 
     expect(env.fakeTimersModern).toBeDefined();
   });
+
+  it('should respect userAgent option', () => {
+    const env = new JSDomEnvironment(
+      makeProjectConfig({
+        testEnvironmentOptions: {
+          userAgent: 'foo',
+        },
+      }),
+    );
+
+    expect(env.dom.window.navigator.userAgent).toEqual('foo');
+  });
 });
diff --git a/packages/jest-environment-jsdom/src/index.ts b/packages/jest-environment-jsdom/src/index.ts
@@ -6,7 +6,7 @@
  */
 
 import type {Context} from 'vm';
-import {JSDOM, VirtualConsole} from 'jsdom';
+import {JSDOM, ResourceLoader, VirtualConsole} from 'jsdom';
 import type {EnvironmentContext, JestEnvironment} from '@jest/environment';
 import {LegacyFakeTimers, ModernFakeTimers} from '@jest/fake-timers';
 import type {Config, Global} from '@jest/types';
@@ -33,6 +33,12 @@ class JSDOMEnvironment implements JestEnvironment {
   constructor(config: Config.ProjectConfig, options?: EnvironmentContext) {
     this.dom = new JSDOM('<!DOCTYPE html>', {
       pretendToBeVisual: true,
+      resources:
+        typeof config.testEnvironmentOptions.userAgent === 'string'
+          ? new ResourceLoader({
+              userAgent: config.testEnvironmentOptions.userAgent,
+            })
+          : undefined,
       runScripts: 'dangerously',
       url: config.testURL,
       virtualConsole: new VirtualConsole().sendTo(options?.console || console),
