fix(runtime): $fetch.create can't set the default configuration

examples/app-vitest-full/tests/nuxt/server.spec.ts

@@ -1,4 +1,4 @@
-import { describe, expect, it } from 'vitest'
+import { describe, expect, it, vi } from 'vitest'
 
 import { mountSuspended, registerEndpoint } from '@nuxt/test-utils/runtime'
 
@@ -176,4 +176,53 @@ describe('server mocks and data fetching', () => {
     expect(await fetch(new URL('http://localhost:3000/with-url')).then(res => res.json())).toMatchObject({ title: 'with-url', data: {} })
     expect(await fetch(new URL('http://localhost:3000/with-url?q=1')).then(res => res.json())).toMatchObject({ title: 'with-url', data: { q: '1' } })
   })
+
+  it('can mock fetch requests with fetch.create', async () => {
+    registerEndpoint('/fetch-create/1', event => ({
+      title: 'title from mocked api1',
+      headers: getHeaders(event),
+    }))
+    registerEndpoint('/fetch-create/2', event => ({
+      title: 'title from mocked api2',
+      headers: getHeaders(event),
+    }))
+    registerEndpoint('/fetch-create/error', () =>
+      new Response(undefined, { status: 500, statusText: 'Mock Server Error' }),
+    )
+
+    const onRequest = vi.fn()
+    const onResponse = vi.fn()
+    const onRequestError = vi.fn()
+    const onResponseError = vi.fn()
+
+    const fetch = $fetch.create({
+      baseURL: '/fetch-create',
+      retry: false,
+      onRequest,
+      onResponse,
+      onRequestError,
+      onResponseError,
+      headers: {
+        authorization: 'Bearer <access_token>',
+      },
+    })
+
+    expect(await fetch<unknown>('/1')).toMatchObject({
+      title: 'title from mocked api1',
+      headers: { authorization: 'Bearer <access_token>' },
+    })
+
+    expect(await fetch<unknown>('/2')).toMatchObject({
+      title: 'title from mocked api2',
+      headers: { authorization: 'Bearer <access_token>' },
+    })
+
+    await expect(fetch<unknown>('/error')).rejects.toMatchObject({ status: 500, statusText: 'Mock Server Error' })
+    await expect(fetch<unknown>('/error', { baseURL: '"INVALID"' })).rejects.toThrowError()
+
+    expect(onRequest).toBeCalledTimes(4)
+    expect(onResponse).toBeCalledTimes(3)
+    expect(onRequestError).toBeCalledTimes(1)
+    expect(onResponseError).toBeCalledTimes(1)
+  })
 })

examples/app-vitest/test/registerEndpoint.nuxt.spec.ts

@@ -21,9 +21,9 @@ describe('registerEndpoint tests', () => {
     registerEndpoint('/test2/', () => endpoint())
     const component = await mountSuspended(TestFetchComponent)
 
-    component
+    await component
       .find<HTMLButtonElement>('#custom-fetcher')
-      .element.click()
+      .trigger('click')
 
     expect(endpoint).toHaveBeenCalled()
     component.unmount()

src/runtime/shared/environment.ts

@@ -101,11 +101,6 @@ export async function setupWindow(win: NuxtWindow, environmentOptions: { nuxt: N
   // @ts-expect-error fetch types differ slightly
   win.$fetch = createFetch({ fetch: win.fetch, Headers: win.Headers })
 
-  // @ts-expect-error fetch types differ slightly
-  win.$fetch.create = (options = {}) => {
-    return createFetch({ fetch: win.fetch, Headers: win.Headers, ...options })
-  }
-
   win.__registry = registry
   win.__app = h3App