test: failing test for binary request bodies (mswjs#929)

test/rest-api/binary.mocks.ts

@@ -0,0 +1,14 @@
+import { setupWorker, rest } from 'msw'
+
+const worker = setupWorker(
+  rest.post('https://test.mswjs.io/api/binary', async (req, res, ctx) => {
+    const body = await req.arrayBuffer()
+    const hexNumbers = Array.from(new Uint8Array(body))
+      .map((byte) => byte.toString(16))
+      .join(' ')
+
+    return res(ctx.json({ result: hexNumbers }))
+  }),
+)
+
+worker.start()

test/rest-api/binary.test.ts

@@ -0,0 +1,33 @@
+import * as path from 'path'
+import { pageWith } from 'page-with'
+
+function createRuntime() {
+  return pageWith({
+    example: path.resolve(__dirname, 'binary.mocks.ts'),
+  })
+}
+
+test('transfers binary data without corruption', async () => {
+  const runtime = await createRuntime()
+
+  const payload = [0xff, 0xd8, 0xff, 0xe0, 0x00, 0x10, 0x4a, 0x46]
+  const expectedResult = payload.map((byte) => byte.toString(16)).join(' ')
+
+  runtime.page.evaluate((payload) => {
+    return fetch('https://test.mswjs.io/api/binary', {
+      method: 'POST',
+      body: new Uint8Array(payload).buffer,
+    })
+  }, payload)
+
+  const res = await runtime.page.waitForResponse(
+    'https://test.mswjs.io/api/binary',
+  )
+  const status = res.status()
+  const headers = await res.allHeaders()
+  const body = await res.json()
+
+  expect(status).toBe(200)
+  expect(headers).toHaveProperty('x-powered-by', 'msw')
+  expect(body).toEqual({ result: expectedResult })
+})