feat: add stream pipe response

src/app.ts

@@ -3,7 +3,7 @@ import type { IncomingMessage, ServerResponse } from './types/node'
 import { lazyHandle, promisifyHandle } from './handle'
 import type { Handle, LazyHandle, Middleware, PHandle } from './handle'
 import { createError, sendError } from './error'
-import { send, MIMES } from './utils'
+import { send, isStream, MIMES } from './utils'
 
 export interface Layer {
   route: string
@@ -115,8 +115,8 @@ export function createHandle (stack: Stack, options: AppOptions): PHandle {
       if (type === 'string') {
         return send(res, val, MIMES.html)
       } else if (type === 'object' || type === 'boolean' || type === 'number' /* IS_JSON */) {
-        if (val && val.buffer) {
-          return send(res, val)
+        if (val && (val.buffer || isStream(val))) {
+          return send(res, val, MIMES.html)
         } else if (val instanceof Error) {
           throw createError(val)
         } else {

src/utils/response.ts

@@ -9,8 +9,13 @@ export function send (res: ServerResponse, data: any, type?: string) {
   }
   return new Promise((resolve) => {
     defer(() => {
-      res.end(data)
-      resolve(undefined)
+      if (isStream(data)) {
+        data.pipe(res)
+        data.on('end', () => resolve(undefined))
+      } else {
+        res.end(data)
+        resolve(undefined)
+      }
     })
   })
 }
@@ -41,3 +46,7 @@ export function appendHeader (res: ServerResponse, name: string, value: string):
 
   res.setHeader(name, current.concat(value))
 }
+
+export function isStream (data: any) {
+  return typeof data === 'object' && typeof data.pipe === 'function' && typeof data.on === 'function'
+}

test/app.test.ts

@@ -1,3 +1,4 @@
+import { Readable } from 'stream'
 import supertest, { SuperTest, Test } from 'supertest'
 import { describe, it, expect, beforeEach } from 'vitest'
 import { createApp, App } from '../src'
@@ -18,6 +19,29 @@ describe('app', () => {
     expect(res.body).toEqual({ url: '/' })
   })
 
+  it('can return Buffer directly', async () => {
+    app.use(() => Buffer.from('<h1>Hello world!</h1>', 'utf8'))
+    const res = await request.get('/')
+
+    expect(res.text).toBe('<h1>Hello world!</h1>')
+    expect(res.header['content-type']).toBe('text/html')
+  })
+
+  it('can return ReadableStream directly', async () => {
+    app.use(() => {
+      const readable = new Readable()
+      readable._read = () => {}
+      readable.push(Buffer.from('<h1>Hello world!</h1>', 'utf8'))
+      readable.push(null)
+      return readable
+    })
+    const res = await request.get('/')
+
+    expect(res.text).toBe('<h1>Hello world!</h1>')
+    expect(res.header['content-type']).toBe('text/html')
+    expect(res.header['transfer-encoding']).toBe('chunked')
+  })
+
   it('can return HTML directly', async () => {
     app.use(() => '<h1>Hello world!</h1>')
     const res = await request.get('/')