docs(chinese): translate testing

Author: phk422

docs/zh/openapi-fetch/testing.md

@@ -1,11 +1,67 @@
 ---
-title: Testing
+title: 测试
 ---
 
-# Testing
+# 测试
 
-::: warning
+最好在支持 TypeScript 的测试运行器中进行 openapi-fetch 的测试，比如 [Vitest](https://vitest.dev/) 或 Jest。
 
-This article is a stub. Please help [expand it](https://github.com/drwpow/openapi-typescript/tree/main/docs/zh/)!
+## 模拟请求
 
-:::
+要测试请求，可以使用 `fetch` 选项并提供任何 spy 函数，比如 `vi.fn()`（Vitest）或 `jest.fn()`（Jest）。
+
+```ts
+import createClient from "openapi-fetch";
+import { expect, test, vi } from "vitest";
+import type { paths } from "./api/v1";
+
+test("my request", async () => {
+  const mockFetch = vi.fn();
+  const client = createClient<paths>({
+    baseUrl: "https://my-site.com/api/v1/",
+    fetch: mockFetch,
+  });
+
+  const reqBody = { name: "test" };
+  await client.PUT("/tag", { body: reqBody });
+
+  const req = mockFetch.mock.calls[0][0];
+  expect(req.url).toBe("/tag");
+  expect(await req.json()).toEqual(reqBody);
+});
+```
+
+## 模拟响应
+
+任何能够模拟原生 `fetch` API 的库都可以工作，比如 [vitest-fetch-mock](https://github.com/IanVS/vitest-fetch-mock):
+
+```ts
+import createClient from "openapi-fetch";
+import { afterEach, beforeAll, expect, test, vi } from "vitest";
+import type { paths } from "./api/v1";
+
+const fetchMocker = createFetchMock(vi);
+
+beforeAll(() => {
+  fetchMocker.enableMocks();
+});
+afterEach(() => {
+  fetchMocker.resetMocks();
+});
+
+test("my API call", async () => {
+  const rawData = { test: { data: "foo" } };
+  mockFetchOnce({
+    status: 200,
+    body: JSON.stringify(rawData),
+  });
+  const client = createClient<paths>({
+    baseUrl: "https://my-site.com/api/v1/",
+  });
+
+  const { data, error } = await client.GET("/foo");
+
+  expect(data).toEqual(rawData);
+  expect(error).toBeUndefined();
+});
+```