test: add .use() replacement regression tests

test/browser/msw-api/regression/2129-worker-use.mocks.ts

@@ -0,0 +1,17 @@
+import { http, HttpResponse } from 'msw'
+import { setupWorker } from 'msw/browser'
+
+const worker = setupWorker()
+worker.start()
+
+worker.use(
+  http.get('/v1/issues', () => {
+    return HttpResponse.text('get-body')
+  }),
+)
+
+worker.use(
+  http.post('/v1/issues', () => {
+    return HttpResponse.text('post-body')
+  }),
+)

test/browser/msw-api/regression/2129-worker-use.test.ts

@@ -0,0 +1,17 @@
+/**
+ * @see https://github.com/mswjs/msw/issues/2129
+ */
+import { test, expect } from '../../playwright.extend'
+
+test('handles a stream response without throwing a timeout error', async ({
+  loadExample,
+  fetch,
+}) => {
+  await loadExample(require.resolve('./2129-worker-use.mocks.ts'))
+
+  const getResponse = await fetch('/v1/issues')
+  expect(await getResponse.text()).toBe('get-body')
+
+  const postResponse = await fetch('/v1/issues', { method: 'POST' })
+  expect(await postResponse.text()).toBe('post-body')
+})

test/node/regressions/2129-server-use.test.ts

@@ -0,0 +1,41 @@
+/**
+ * @vitest-environment node
+ * @see https://github.com/mswjs/msw/issues/2129
+ */
+import { http, HttpResponse } from 'msw'
+import { setupServer } from 'msw/node'
+
+const server = setupServer()
+
+beforeAll(async () => {
+  server.listen()
+})
+
+afterEach(() => {
+  server.resetHandlers()
+})
+
+afterAll(async () => {
+  server.close()
+})
+
+it('does not override existing handlers when adding override for a different method', async () => {
+  server.use(
+    http.get('http://localhost/v1/issues', () => {
+      return HttpResponse.text('get-body')
+    }),
+  )
+  server.use(
+    http.post('http://localhost/v1/issues', () => {
+      return HttpResponse.text('post-body')
+    }),
+  )
+
+  const geetResponse = await fetch('http://localhost/v1/issues')
+  expect(await geetResponse.text()).toBe('get-body')
+
+  const postResponse = await fetch('http://localhost/v1/issues', {
+    method: 'POST',
+  })
+  expect(await postResponse.text()).toBe('post-body')
+})