jestjs · cpojer · Dec 6, 2017 · Dec 2, 2017 · Dec 2, 2017 · Dec 2, 2017
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -51,6 +51,8 @@
 
 ### Features
 
+* `[jest-config]` Add `testEnvironmentOptions` to apply to jsdom options or node context.
+  ([#5003](https://github.com/facebook/jest/pull/5003))
 * `[jest-jasmine2]` Update Timeout error message to `jest.timeout` and display current timeout value
   ([#4990](https://github.com/facebook/jest/pull/4990))
 * `[jest-runner]` Enable experimental detection of leaked contexts

diff --git a/docs/Configuration.md b/docs/Configuration.md
@@ -726,6 +726,17 @@ class CustomEnvironment extends NodeEnvironment {
 }
 ```
 
+### `testEnvironmentOptions` [Object]
+
+##### available in Jest **2?.0.0+**
+
+Default: `{}`
+
+Test environment options that will be passed to the `testEnvironment`.  The
+relevant options depend on the environment.  For example you can override
+options given to [jsdom](https://github.com/tmpvar/jsdom) such as
+`{userAgent: "Agent/007"}`.
+
 ### `testMatch` [array<string>]
 
 ##### available in Jest **19.0.0+**

diff --git a/integration_tests/__tests__/__snapshots__/show_config.test.js.snap b/integration_tests/__tests__/__snapshots__/show_config.test.js.snap
@@ -39,6 +39,7 @@ exports[`--showConfig outputs config info and exits 1`] = `
       \\"setupFiles\\": [],
       \\"snapshotSerializers\\": [],
       \\"testEnvironment\\": \\"jest-environment-jsdom\\",
+      \\"testEnvironmentOptions\\": {},
       \\"testLocationInResults\\": false,
       \\"testMatch\\": [
         \\"**/__tests__/**/*.js?(x)\\",

diff --git a/packages/jest-config/src/defaults.js b/packages/jest-config/src/defaults.js
@@ -56,6 +56,7 @@ export default ({
   runner: 'jest-runner',
   snapshotSerializers: [],
   testEnvironment: 'jest-environment-jsdom',
+  testEnvironmentOptions: {},
   testFailureExitCode: 1,
   testLocationInResults: false,
   testMatch: ['**/__tests__/**/*.js?(x)', '**/?(*.)(spec|test).js?(x)'],

diff --git a/packages/jest-config/src/index.js b/packages/jest-config/src/index.js
@@ -147,6 +147,7 @@ const getConfigs = (
       skipNodeResolution: options.skipNodeResolution,
       snapshotSerializers: options.snapshotSerializers,
       testEnvironment: options.testEnvironment,
+      testEnvironmentOptions: options.testEnvironmentOptions,
       testLocationInResults: options.testLocationInResults,
       testMatch: options.testMatch,
       testPathIgnorePatterns: options.testPathIgnorePatterns,

diff --git a/packages/jest-config/src/normalize.js b/packages/jest-config/src/normalize.js
@@ -481,6 +481,7 @@ export default function normalize(options: InitialOptions, argv: Argv) {
       case 'silent':
       case 'skipNodeResolution':
       case 'testEnvironment':
+      case 'testEnvironmentOptions':
       case 'testFailureExitCode':
       case 'testLocationInResults':
       case 'testNamePattern':

diff --git a/packages/jest-config/src/valid_config.js b/packages/jest-config/src/valid_config.js
@@ -77,6 +77,7 @@ export default ({
   skipNodeResolution: false,
   snapshotSerializers: ['my-serializer-module'],
   testEnvironment: 'jest-environment-jsdom',
+  testEnvironmentOptions: {},
   testFailureExitCode: 1,
   testLocationInResults: false,
   testMatch: ['**/__tests__/**/*.js?(x)', '**/?(*.)(spec|test).js?(x)'],

diff --git a/packages/jest-environment-jsdom/src/index.js b/packages/jest-environment-jsdom/src/index.js
@@ -23,11 +23,17 @@ class JSDOMEnvironment {
   moduleMocker: ?ModuleMocker;
 
   constructor(config: ProjectConfig) {
-    this.dom = new JSDOM('<!DOCTYPE html>', {
-      pretendToBeVisual: true,
-      runScripts: 'dangerously',
-      url: config.testURL,
-    });
+    this.dom = new JSDOM(
+      '<!DOCTYPE html>',
+      Object.assign(
+        {
+          pretendToBeVisual: true,
+          runScripts: 'dangerously',
+          url: config.testURL,
+        },
+        config.testEnvironmentOptions,
+      ),
+    );
     const global = (this.global = this.dom.window.document.defaultView);
     // Node's error-message stack size is limited at 10, but it's pretty useful
     // to see more than that when a test fails.

diff --git a/packages/jest-environment-node/src/index.js b/packages/jest-environment-node/src/index.js
@@ -30,7 +30,10 @@ class NodeEnvironment {
 
   constructor(config: ProjectConfig) {
     this.context = vm.createContext();
-    const global = (this.global = vm.runInContext('this', this.context));
+    const global = (this.global = vm.runInContext(
+      'this',
+      Object.assign(this.context, config.testEnvironmentOptions),
+    ));
     global.global = global;
     global.clearInterval = clearInterval;
     global.clearTimeout = clearTimeout;

diff --git a/test_utils.js b/test_utils.js
@@ -89,6 +89,7 @@ const DEFAULT_PROJECT_CONFIG: ProjectConfig = {
   skipNodeResolution: false,
   snapshotSerializers: [],
   testEnvironment: 'node',
+  testEnvironmentOptions: {},
   testLocationInResults: false,
   testMatch: [],
   testPathIgnorePatterns: [],

diff --git a/types/Config.js b/types/Config.js
@@ -48,6 +48,7 @@ export type DefaultOptions = {|
   runTestsByPath: boolean,
   snapshotSerializers: Array<Path>,
   testEnvironment: string,
+  testEnvironmentOptions: Object,
   testFailureExitCode: string | number,
   testLocationInResults: boolean,
   testMatch: Array<Glob>,
@@ -122,6 +123,7 @@ export type InitialOptions = {
   skipNodeResolution?: boolean,
   snapshotSerializers?: Array<Path>,
   testEnvironment?: string,
+  testEnvironmentOptions?: Object,
   testFailureExitCode?: string | number,
   testLocationInResults?: boolean,
   testMatch?: Array<Glob>,
@@ -224,6 +226,7 @@ export type ProjectConfig = {|
   skipNodeResolution: boolean,
   snapshotSerializers: Array<Path>,
   testEnvironment: string,
+  testEnvironmentOptions: Object,
   testMatch: Array<Glob>,
   testLocationInResults: boolean,
   testPathIgnorePatterns: Array<string>,