fix: Client.stream writableNeedDrain

Fixes: #441
Refs: nodejs/node#35348
Refs: nodejs/node#35341

lib/client-stream.js

@@ -109,6 +109,12 @@ class StreamHandler extends AsyncResource {
     })
 
     this.res = res
+
+    const needDrain = res.writableNeedDrain !== undefined
+      ? res.writableNeedDrain
+      : res._writableState && res._writableState.needDrain
+
+    return needDrain !== true
   }
 
   onData (chunk) {

lib/core/client.js

@@ -374,19 +374,37 @@ class Parser extends HTTPParser {
     this.headers = null
     this.shouldKeepAlive = false
     this.request = null
+    this.paused = false
+    this.queue = []
 
     this._resume = () => {
-      // TODO: Resume parser.
+      this.paused = false
+
+      while (this.queue.length) {
+        const [fn, ...args] = this.queue.shift()
+
+        fn.apply(this, args)
+
+        if (this.paused) {
+          return
+        }
+      }
+
       socketResume(socket)
     }
 
     this._pause = () => {
-      // TODO: Pause parser.
+      this.paused = true
       socketPause(socket)
     }
   }
 
   [HTTPParser.kOnHeaders] (rawHeaders) {
+    if (this.paused) {
+      this.queue.push([this[HTTPParser.kOnHeaders], rawHeaders])
+      return
+    }
+
     if (this.headers) {
       Array.prototype.push.apply(this.headers, rawHeaders)
     } else {
@@ -395,6 +413,11 @@ class Parser extends HTTPParser {
   }
 
   [HTTPParser.kOnExecute] (ret) {
+    if (this.paused) {
+      this.queue.push([this[HTTPParser.kOnExecute], ret])
+      return
+    }
+
     const { upgrade, socket } = this
 
     if (!Number.isFinite(ret)) {
@@ -465,6 +488,12 @@ class Parser extends HTTPParser {
 
   [HTTPParser.kOnHeadersComplete] (versionMajor, versionMinor, rawHeaders, method,
     url, statusCode, statusMessage, upgrade, shouldKeepAlive) {
+    if (this.paused) {
+      this.queue.push([this[HTTPParser.kOnHeadersComplete], versionMajor, versionMinor, rawHeaders, method,
+        url, statusCode, statusMessage, upgrade, shouldKeepAlive])
+      return
+    }
+
     const { client, socket } = this
 
     const request = client[kQueue][client[kRunningIdx]]
@@ -560,6 +589,11 @@ class Parser extends HTTPParser {
   }
 
   [HTTPParser.kOnBody] (chunk, offset, length) {
+    if (this.paused) {
+      this.queue.push([this[HTTPParser.kOnBody], chunk, offset, length])
+      return
+    }
+
     const { socket, statusCode, request } = this
 
     if (socket.destroyed) {
@@ -578,6 +612,11 @@ class Parser extends HTTPParser {
   }
 
   [HTTPParser.kOnMessageComplete] () {
+    if (this.paused) {
+      this.queue.push([this[HTTPParser.kOnMessageComplete]])
+      return
+    }
+
     const { client, socket, statusCode, headers, upgrade, request, trailers } = this
 
     if (socket.destroyed) {
@@ -785,6 +824,7 @@ function connect (client) {
 }
 
 function socketPause (socket) {
+  // TODO: Pause parser.
   if (socket._handle && socket._handle.reading) {
     socket._handle.reading = false
     const err = socket._handle.readStop()
@@ -795,6 +835,7 @@ function socketPause (socket) {
 }
 
 function socketResume (socket) {
+  // TODO: Resume parser.
   if (socket._handle && !socket._handle.reading) {
     socket._handle.reading = true
     const err = socket._handle.readStart()

lib/core/request.js

@@ -162,6 +162,7 @@ class Request {
 
   onBody (chunk, offset, length) {
     assert(!this.aborted)
+    assert(!this[kPaused])
 
     if (this[kTimeout] && this[kTimeout].refresh) {
       this[kTimeout].refresh()

test/client-stream.js

@@ -657,3 +657,47 @@ test('stream body destroyed on invalid callback', (t) => {
     }
   })
 })
+
+test('stream needDrain', (t) => {
+  t.plan(1)
+
+  const server = createServer((req, res) => {
+    res.end(Buffer.alloc(4096))
+  })
+  t.tearDown(server.close.bind(server))
+
+  server.listen(0, async () => {
+    const client = new Client(`http://localhost:${server.address().port}`)
+    t.tearDown(() => {
+      console.error(3)
+      client.destroy()
+    })
+
+    const dst = new PassThrough()
+    dst.pause()
+
+    while (dst.write(Buffer.alloc(4096))) {
+
+    }
+
+    const orgWrite = dst.write
+    dst.write = () => t.fail()
+    const p = client.stream({
+      path: '/',
+      method: 'GET'
+    }, () => {
+      return dst
+    })
+
+    setTimeout(() => {
+      dst.write = (...args) => {
+        orgWrite.call(dst, ...args)
+      }
+      dst.resume()
+    }, 1e3)
+
+    await p
+
+    t.pass()
+  })
+})