http2: fix compat stream read handling, add tests

Handle edge case where stream pause is called between resume being
called and actually evaluated. Other minor adjustments to avoid
various edge cases around stream events. Add new tests that cover
all changes.

Fixes: https://github.com/nodejs/node/issues/15491
PR-URL: https://github.com/nodejs/node/pull/15503
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/http2/compat.js

@@ -97,46 +97,50 @@ function onStreamError(error) {
 }
 
 function onRequestPause() {
-  this[kStream].pause();
+  const stream = this[kStream];
+  if (stream)
+    stream.pause();
 }
 
 function onRequestResume() {
-  this[kStream].resume();
+  const stream = this[kStream];
+  if (stream)
+    stream.resume();
 }
 
-function onRequestDrain() {
+function onStreamDrain() {
-  if (this.isPaused())
-    this.resume();
-}
-
-function onStreamResponseDrain() {
   this[kResponse].emit('drain');
 }
 
+// TODO Http2Stream does not emit 'close'
 function onStreamClosedRequest() {
   this[kRequest].push(null);
 }
 
+// TODO Http2Stream does not emit 'close'
 function onStreamClosedResponse() {
-  const res = this[kResponse];
+  this[kResponse].emit('finish');
-  res.writable = false;
-  res.emit('finish');
 }
 
 function onStreamAbortedRequest(hadError, code) {
-  if ((this.writable) ||
+  const request = this[kRequest];
-      (this._readableState && !this._readableState.ended)) {
+  if (request[kState].closed === false) {
-    this.emit('aborted', hadError, code);
+    request.emit('aborted', hadError, code);
-    this.emit('close');
+    request.emit('close');
   }
 }
 
 function onStreamAbortedResponse() {
-  if (this.writable) {
+  const response = this[kResponse];
-    this.emit('close');
+  if (response[kState].closed === false) {
+    response.emit('close');
   }
 }
 
+function resumeStream(stream) {
+  stream.resume();
+}
+
 class Http2ServerRequest extends Readable {
   constructor(stream, headers, options, rawHeaders) {
     super(options);
@@ -158,13 +162,12 @@ class Http2ServerRequest extends Readable {
     stream.on('end', onStreamEnd);
     stream.on('error', onStreamError);
     stream.on('close', onStreamClosedRequest);
-    stream.on('aborted', onStreamAbortedRequest.bind(this));
+    stream.on('aborted', onStreamAbortedRequest);
     const onfinish = this[kFinish].bind(this);
     stream.on('streamClosed', onfinish);
     stream.on('finish', onfinish);
     this.on('pause', onRequestPause);
     this.on('resume', onRequestResume);
-    this.on('drain', onRequestDrain);
   }
 
   get closed() {
@@ -221,7 +224,7 @@ class Http2ServerRequest extends Readable {
   _read(nread) {
     const stream = this[kStream];
     if (stream !== undefined) {
-      stream.resume();
+      process.nextTick(resumeStream, stream);
     } else {
       this.emit('error', new errors.Error('ERR_HTTP2_STREAM_CLOSED'));
     }
@@ -279,9 +282,9 @@ class Http2ServerResponse extends Stream {
     this[kStream] = stream;
     stream[kResponse] = this;
     this.writable = true;
-    stream.on('drain', onStreamResponseDrain);
+    stream.on('drain', onStreamDrain);
     stream.on('close', onStreamClosedResponse);
-    stream.on('aborted', onStreamAbortedResponse.bind(this));
+    stream.on('aborted', onStreamAbortedResponse);
     const onfinish = this[kFinish].bind(this);
     stream.on('streamClosed', onfinish);
     stream.on('finish', onfinish);

test/parallel/test-http2-compat-serverrequest-pause.js

@@ -0,0 +1,53 @@
+// Flags: --expose-http2
+'use strict';
+
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+const assert = require('assert');
+const h2 = require('http2');
+
+// Check that pause & resume work as expected with Http2ServerRequest
+
+const testStr = 'Request Body from Client';
+
+const server = h2.createServer();
+
+server.on('request', common.mustCall((req, res) => {
+  let data = '';
+  req.pause();
+  req.setEncoding('utf8');
+  req.on('data', common.mustCall((chunk) => (data += chunk)));
+  setTimeout(common.mustCall(() => {
+    assert.strictEqual(data, '');
+    req.resume();
+  }), common.platformTimeout(100));
+  req.on('end', common.mustCall(() => {
+    assert.strictEqual(data, testStr);
+    res.end();
+  }));
+
+  // shouldn't throw if underlying Http2Stream no longer exists
+  res.on('finish', common.mustCall(() => process.nextTick(() => {
+    assert.doesNotThrow(() => req.pause());
+    assert.doesNotThrow(() => req.resume());
+  })));
+}));
+
+server.listen(0, common.mustCall(() => {
+  const port = server.address().port;
+
+  const client = h2.connect(`http://localhost:${port}`);
+  const request = client.request({
+    ':path': '/foobar',
+    ':method': 'POST',
+    ':scheme': 'http',
+    ':authority': `localhost:${port}`
+  });
+  request.resume();
+  request.end(testStr);
+  request.on('end', common.mustCall(function() {
+    client.destroy();
+    server.close();
+  }));
+}));

test/parallel/test-http2-compat-serverrequest-pipe.js

@@ -0,0 +1,48 @@
+// Flags: --expose-http2
+'use strict';
+
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+const assert = require('assert');
+const http2 = require('http2');
+const fs = require('fs');
+const path = require('path');
+
+// piping should work as expected with createWriteStream
+
+const loc = path.join(common.fixturesDir, 'person.jpg');
+const fn = path.join(common.tmpDir, 'http2pipe.jpg');
+common.refreshTmpDir();
+
+const server = http2.createServer();
+
+server.on('request', common.mustCall((req, res) => {
+  const dest = req.pipe(fs.createWriteStream(fn));
+  dest.on('finish', common.mustCall(() => {
+    assert.deepStrictEqual(fs.readFileSync(loc), fs.readFileSync(fn));
+    fs.unlinkSync(fn);
+    res.end();
+  }));
+}));
+
+server.listen(0, common.mustCall(() => {
+  const port = server.address().port;
+  const client = http2.connect(`http://localhost:${port}`);
+
+  let remaining = 2;
+  function maybeClose() {
+    if (--remaining === 0) {
+      server.close();
+      client.destroy();
+    }
+  }
+
+  const req = client.request({ ':method': 'POST' });
+  req.on('response', common.mustCall());
+  req.resume();
+  req.on('end', common.mustCall(maybeClose));
+  const str = fs.createReadStream(loc);
+  str.on('end', common.mustCall(maybeClose));
+  str.pipe(req);
+}));

test/parallel/test-http2-compat-serverresponse-drain.js

@@ -0,0 +1,44 @@
+// Flags: --expose-http2
+'use strict';
+
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+const assert = require('assert');
+const h2 = require('http2');
+
+// Check that drain event is passed from Http2Stream
+
+const testString = 'tests';
+
+const server = h2.createServer();
+
+server.on('request', common.mustCall((req, res) => {
+  res.stream._writableState.highWaterMark = testString.length;
+  assert.strictEqual(res.write(testString), false);
+  res.on('drain', common.mustCall(() => res.end(testString)));
+}));
+
+server.listen(0, common.mustCall(() => {
+  const port = server.address().port;
+
+  const client = h2.connect(`http://localhost:${port}`);
+  const request = client.request({
+    ':path': '/foobar',
+    ':method': 'POST',
+    ':scheme': 'http',
+    ':authority': `localhost:${port}`
+  });
+  request.resume();
+  request.end();
+
+  let data = '';
+  request.setEncoding('utf8');
+  request.on('data', (chunk) => (data += chunk));
+
+  request.on('end', common.mustCall(function() {
+    assert.strictEqual(data, testString.repeat(2));
+    client.destroy();
+    server.close();
+  }));
+}));