Can't pipe stream to ctx.res

I’m trying to pipe streams to my response but it seems didn’t work

Simple test case:

const Koa = require('koa');
const app = new Koa();
const Router = require('koa-better-router');
const router = Router().loadMethods();
const request = require('request');

app.use(async (ctx, next) => {
    const start = new Date();
    await next();
    const ms = new Date() - start;
    console.log(`${ctx.method} ${ctx.url} - ${ms}ms`);
});

router.get('/', async (ctx) => {
    ctx.req.pipe(request(`https://www.google.com/?q=${ctx.query.q}`)).pipe(ctx.res);
});

app.use(router.middleware());

app.listen(3000, () => {
    console.log('listening on port 3000');
});

An error occurred:

$ node index.js 
listening on port 3000
GET / - 35ms
internal/streams/legacy.js:59
      throw er; // Unhandled stream error in pipe.
      ^

Error: write after end
    at ServerResponse.write (_http_outgoing.js:450:15)
    at Request.ondata (internal/streams/legacy.js:16:26)
    at emitOne (events.js:96:13)
    at Request.emit (events.js:189:7)
    at IncomingMessage.<anonymous> (/Users/knowlet/test/node_modules/request/request.js:1088:12)
    at emitOne (events.js:96:13)
    at IncomingMessage.emit (events.js:189:7)
    at IncomingMessage.Readable.read (_stream_readable.js:381:10)
    at flow (_stream_readable.js:761:34)
    at resume_ (_stream_readable.js:743:3)

And req.pipe(request(...)).pipe(res) works in express.js, I’m wondering is there anything I do wrong?

$ node -v
v7.6.0

[PlasmaPower]

You’ll want to let Koa handle the stream:

ctx.body = ctx.req.pipe(request(`https://www.google.com/?q=${ctx.query.q}`));

[catamphetamine]

you can use ctx.respond = false

Oh, you have that. Ok, that will do.

However, that is not the recommended solution, and it may cause problems with other middleware.

How about this

.use(async (ctx) =>
{
	// https://medium.com/@aickin/whats-new-with-server-side-rendering-in-react-16-9b0d78585d67
	ctx.res.write(header)
	await pipe(stream, ctx.res, { end: false })
	ctx.res.write(footer)
	ctx.res.end()
})

// Pipes `from` stream to `to` stream.
// Returns a `Promise`.
function pipe(from, to, options)
{
	return new Promise((resolve, reject) =>
	{
		from.pipe(to, options)
		from.on('error', reject)
		from.on('end', resolve)
	})
}