test: add unit test for verifying XHR body consumption (#632)

test/modules/XMLHttpRequest/regressions/xhr-axios-xhr-adapter.test.ts

@@ -3,14 +3,14 @@
  * @note This issue is only reproducible in "happy-dom".
  * @see https://github.com/mswjs/msw/issues/1816
  */
-import { beforeAll, afterAll, it, expect } from 'vitest'
+import { beforeAll, afterAll, describe, it, expect } from 'vitest'
 import axios from 'axios'
 /**
  * @note Use `Response` from Undici because "happy-dom"
  * does not implement ReadableStream at all. They use
  * Node's Readable instead, which is completely incompatible.
  */
-import { Response as UndiciResponse } from 'undici'
+import { Response as UndiciResponse, Request as UndiciRequest } from 'undici'
 import { XMLHttpRequestInterceptor } from '../../../../src/interceptors/XMLHttpRequest'
 
 const request = axios.create({
@@ -39,3 +39,34 @@ it('performs a request with the "xhr" axios adapter', async () => {
   expect(res.status).toBe(200)
   expect(res.data).toBe('Hello world')
 })
+
+describe("wth the undici Request", () => {
+  /**
+   * @note Use `Request` from Undici because "happy-dom"
+   * does not prevent cloning after consuming the body buffer
+   * This will verify standard behavior
+   */
+  const NativeRequest = global.Request
+  beforeAll(() => {
+    global.Request = UndiciRequest as unknown as typeof Request
+  })
+
+  afterAll(() => {
+    global.Request = NativeRequest
+  })
+
+  it('performs a POST request with the "xhr" axios adapter', async () => {
+    interceptor.once('request', async ({ controller, request }) => {
+      // consume the body to ensure respondWith doesn't try to read something it can't
+      await request.arrayBuffer()
+
+      controller.respondWith(
+        new UndiciResponse('Hello world') as unknown as Response
+      )
+    })
+
+    const res = await request.post('/resource', { field: 'value' })
+    expect(res.status).toBe(200)
+    expect(res.data).toBe('Hello world')
+  })
+});