Fetch在Vitest测试中无法解析相对路径：如何模拟浏览器环境？

我在React应用中使用相对路径/api/test发起请求（通过NGINX控制器将流量路由到API或React客户端，二者共用同一基础URL）。

我在msw文档中发现相对路径是受支持的：

// Given your application runs on "http://localhost:8080",
// this request handler URL gets resolved to "http://localhost:8080/invoices"
rest.get('/invoices', invoicesResolver)

Note that relative URL are resolved against the current location (location.origin).

执行console.log(window.location.origin)会输出http://localhost:3000，我认为该origin是由import '@testing-library/jest-dom'设置的。

然而，当我在测试（msw正在模拟API调用）中发起fetch请求时，会收到TypeError: Invalid URL: /api/test错误。

发起请求的代码：

fetch('/api/test')
    .then((response) => response.json())
    .then((data) => console.log(data))

错误信息：

Vitest caught 1 unhandled error during the test run.
This might cause false positive tests. Resolve unhandled errors to make sure your tests are not affected.

⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ Unhandled Rejection ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯
TypeError: Failed to parse URL from /api/test
 ❯ new Request node:internal/deps/undici/undici:9474:19
 ❯ FetchInterceptor.<anonymous> node_modules/@mswjs/interceptors/src/interceptors/fetch/index.ts:42:23
 ❯ step node_modules/@mswjs/interceptors/lib/interceptors/fetch/index.js:59:23
 ❯ Object.next node_modules/@mswjs/interceptors/lib/interceptors/fetch/index.js:40:53
 ❯ node_modules/@mswjs/interceptors/lib/interceptors/fetch/index.js:34:71
 ❯ __awaiter node_modules/@mswjs/interceptors/lib/interceptors/fetch/index.js:30:12
 ❯ globalThis.fetch node_modules/@mswjs/interceptors/src/interceptors/fetch/index.ts:41:42
 ❯ App src/App.tsx:9:3
      7|
      8| function App() {
      9|   fetch('/api/test')
       |   ^
     10|     .then((response) => response.json())
     11|     .then((data) => console.log(data))
 ❯ renderWithHooks node_modules/react-dom/cjs/react-dom.development.js:16305:18

This error originated in "src/App.test.tsx" test file. It doesn't mean the error was thrown inside the file itself, but while it was running.
Caused by: TypeError: Invalid URL: /api/test
 ❯ new URLImpl node_modules/whatwg-url/lib/URL-impl.js:21:13
 ❯ Object.exports.setup node_modules/whatwg-url/lib/URL.js:54:12
 ❯ new URL node_modules/whatwg-url/lib/URL.js:115:22
 ❯ new Request node:internal/deps/undici/undici:9472:25
 ❯ FetchInterceptor.<anonymous> node_modules/@mswjs/interceptors/src/interceptors/fetch/index.ts:42:23
 ❯ step node_modules/@mswjs/interceptors/lib/interceptors/fetch/index.js:59:23
 ❯ Object.next node_modules/@mswjs/interceptors/lib/interceptors/fetch/index.js:40:53
 ❯ node_modules/@mswjs/interceptors/lib/interceptors/fetch/index.js:34:71
 ❯ __awaiter node_modules/@mswjs/interceptors/lib/interceptors/fetch/index.js:30:12

在浏览器中运行代码时没有任何问题。既然document.baseURI和window.location.origin已设置，fetch是如何“识别”它并非运行在浏览器中的？是否可以通过设置window的其他字段来避免该错误？

内容的提问来源于stack exchange，提问作者BPDev