fix(vitest): add types for the new global jsdom variable (#5164)

Author: sheremet-va

docs/config/index.md

@@ -512,7 +512,15 @@ export default <Environment>{
 Vitest also exposes `builtinEnvironments` through `vitest/environments` entry, in case you just want to extend it. You can read more about extending environments in [our guide](/guide/environment).
 
 ::: tip
-Since Vitest 1.3.0 jsdom environment exposes `jsdom` global variable equal to the current [JSDOM](https://github.com/jsdom/jsdom) instance.
+Since Vitest 1.3.0 jsdom environment exposes `jsdom` global variable equal to the current [JSDOM](https://github.com/jsdom/jsdom) instance. If you want TypeScript to recognize it, you can add `vitest/jsdom` to your `tsconfig.json` when you use this environment:
+
+```json
+{
+  "compilerOptions": {
+    "types": ["vitest/jsdom"]
+  }
+}
+```
 :::
 
 ### environmentOptions

packages/vitest/jsdom.d.ts

@@ -0,0 +1,6 @@
+import type { JSDOM } from 'jsdom'
+
+declare global {
+  const jsdom: JSDOM
+}
+export {}

packages/vitest/package.json

@@ -38,6 +38,9 @@
     "./globals": {
       "types": "./globals.d.ts"
     },
+    "./jsdom": {
+      "types": "./jsdom.d.ts"
+    },
     "./importMeta": {
       "types": "./importMeta.d.ts"
     },

test/core/test/environments/jsdom.spec.ts

@@ -105,3 +105,11 @@ test('request doesn\'t support absolute URL because jsdom doesn\'t provide compa
     const _r = new Request('/api', { method: 'GET' })
   }).toThrow(/Failed to parse URL/)
 })
+
+test('jsdom global is exposed', () => {
+  // @ts-expect-error -- jsdom is not exposed in our types because we use a single tsconfig for all
+  const dom = jsdom
+  expect(dom).toBeDefined()
+  dom.reconfigure({ url: 'https://examples.new.com' })
+  expect(location.href).toBe('https://examples.new.com/')
+})