fix(node): keep multipart bytes intact when the request has an encoding set

packages/node/src/body.test.ts

@@ -284,28 +284,44 @@ describe('toStandardBody', () => {
     })
   })
 
-  describe.each(['utf8', 'base64'] as const)('request with %s encoding set', (encoding) => {
-    let standardBody: any
+  describe.each(['utf8', 'latin1', 'base64', 'hex'] as const)(
+    'request with %s encoding set',
+    (encoding) => {
+      // utf8 decodes invalid byte sequences to U+FFFD, so only valid text survives it
+      const bytes =
+        encoding === 'utf8' ? Buffer.from('emoji=😀') : Buffer.from([0xff, 0xfe, 0x00, 0x80, 0x41])
+      let standardBody: any
 
-    async function handler(req: IncomingMessage, res: ServerResponse): Promise<void> {
-      req.setEncoding(encoding)
-      standardBody = await toStandardBody(req)
-      res.end()
-    }
+      async function handler(req: IncomingMessage, res: ServerResponse): Promise<void> {
+        req.setEncoding(encoding)
+        standardBody = await toStandardBody(req)
+        res.end()
+      }
 
-    it('json', async () => {
-      await request(handler).post('/').set('standard-server', 'json').send('{"emoji":"😀"}')
+      it('json', async () => {
+        await request(handler).post('/').set('standard-server', 'json').send('{"emoji":"😀"}')
 
-      expect(standardBody).toEqual({ emoji: '😀' })
-    })
+        expect(standardBody).toEqual({ emoji: '😀' })
+      })
 
-    it('file', async () => {
-      await request(handler).post('/').set('standard-server', 'file').send('emoji=😀')
+      it('file', async () => {
+        await request(handler).post('/').set('standard-server', 'file').send(bytes)
 
-      expect(standardBody).toBeInstanceOf(File)
-      expect(await standardBody.text()).toBe('emoji=😀')
-    })
-  })
+        expect(standardBody).toBeInstanceOf(File)
+        expect(new Uint8Array(await standardBody.arrayBuffer())).toEqual(new Uint8Array(bytes))
+      })
+
+      it('form-data', async () => {
+        await request(handler).post('/').field('emoji', '😀').attach('file', bytes, 'foo.bin')
+
+        expect(standardBody).toBeInstanceOf(FormData)
+        expect(standardBody.get('emoji')).toBe('😀')
+        expect(new Uint8Array(await standardBody.get('file').arrayBuffer())).toEqual(
+          new Uint8Array(bytes),
+        )
+      })
+    },
+  )
 
   describe('http2', () => {
     /**
@@ -462,6 +478,13 @@ describe('toStandardBody', () => {
       expect(await reader.read()).toEqual({ done: false, value: 'hello' })
     })
 
+    it('lets the parser reject form-data without content-type', async () => {
+      const req = Readable.from([Buffer.from('--X--\r\n')]) as IncomingMessage
+      req.headers = { 'standard-server': 'form-data' }
+
+      await expect(toStandardBody(req)).rejects.toThrow(TypeError)
+    })
+
     it('falls back to the content headers if the body hint is invalid', async () => {
       let standardBody: any
 

packages/node/src/body.ts

@@ -162,9 +162,9 @@ export function toNodeHttpBody(
 }
 
 function _streamToFormData(stream: Readable, contentType: string | undefined): Promise<FormData> {
-  const response = new Response(stream, {
+  const response = new Response(toWebReadableStream(stream), {
     headers: {
-      'content-type': contentType,
+      'content-type': contentType ?? '',
     },
   })