adding support for transfer encoding (chunked)

Author: jkyberneees

demos/basic.js

@@ -31,6 +31,11 @@ gateway({
 const service1 = require('restana')({})
 service1
   .get('/hi', (req, res) => res.send('Hello World!'))
+  .get('/hi-chunked', (req, res) => {
+    res.write('Hello ')
+    res.write('World!')
+    res.end()
+  })
   .start(3000).then(() => console.log('Public service listening on 3000 port!'))
 
 const service2 = require('restana')({})

index.js

@@ -103,20 +103,40 @@ const handler = (route, proxy, proxyHandler) => async (req, res, next) => {
 
 const onRequestNoOp = (req, res) => { }
 const onResponse = async (req, res, stream) => {
-  if (!res.hasHeader('content-length')) {
+  const TRANSFER_ENCODING_HEADER_NAME = 'transfer-encoding'
+  const chunked = stream.headers[TRANSFER_ENCODING_HEADER_NAME]
+    ? stream.headers[TRANSFER_ENCODING_HEADER_NAME].endsWith('chunked')
+    : false
+
+  if (req.headers.connection === 'close' && chunked) {
     try {
-      const resBuffer = Buffer.concat(await toArray(stream))
-      res.setHeader('content-length', '' + Buffer.byteLength(resBuffer))
-      res.statusCode = stream.statusCode
-      res.end(resBuffer)
+      // remove transfer-encoding header
+      const transferEncoding = stream.headers[TRANSFER_ENCODING_HEADER_NAME].replace(/(,( )?)?chunked/, '')
+      if (transferEncoding) {
+        res.setHeader(TRANSFER_ENCODING_HEADER_NAME, transferEncoding)
+      } else {
+        res.removeHeader(TRANSFER_ENCODING_HEADER_NAME)
+      }
+
+      if (!stream.headers['content-length']) {
+      // pack all pieces into 1 buffer to calculate content length
+        const resBuffer = Buffer.concat(await toArray(stream))
+
+        // add content-length header and send the merged response buffer
+        res.setHeader('content-length', '' + Buffer.byteLength(resBuffer))
+        res.statusCode = stream.statusCode
+        res.end(resBuffer)
+
+        return
+      }
     } catch (err) {
       res.statusCode = 500
       res.end(err.message)
     }
-  } else {
-    res.statusCode = stream.statusCode
-    pump(stream, res)
   }
+
+  res.statusCode = stream.statusCode
+  pump(stream, res)
 }
 
 module.exports = gateway

test/smoke.test.js

@@ -19,6 +19,11 @@ describe('API Gateway', () => {
     remote.get('/info', (req, res) => res.send({
       name: 'fastify-gateway'
     }))
+    remote.get('/chunked', (req, res) => {
+      res.write('user')
+      res.write('1')
+      res.end()
+    })
     remote.get('/cache', (req, res) => {
       res.setHeader('x-cache-timeout', '1 second')
       res.send({
@@ -279,7 +284,28 @@ describe('API Gateway', () => {
       })
   })
 
-  it('close', async () => {
+  it('(Connection: close) chunked transfer-encoding support', async () => {
+    await request(gateway)
+      .get('/users/chunked')
+      .set({ Connection: 'close' })
+      .expect(200)
+      .then((response) => {
+        expect(response.text).to.equal('user1')
+      })
+  })
+
+  it('(Connection: keep-alive) chunked transfer-encoding support', async () => {
+    await request(gateway)
+      .get('/users/chunked')
+      .set('Connection', 'keep-alive')
+      .then((res) => {
+        expect(res.text).to.equal('user1')
+      })
+  })
+
+  it('close', async function () {
+    this.timeout(10 * 1000)
+
     await remote.close()
     await gateway.close()
   })