http2: fix async context loss when trailers carry END_STREAM

The previous fix (f67e45e070) wrapped header/response event dispatch in
reqAsync.runInAsyncScope(), but missed the stream.push(null) call that
triggers the 'end' event. When END_STREAM arrives on a trailing HEADERS
frame (as gRPC does), the 'end' event fires in the session's async
context instead of the request's context.

Wrap stream.push(null) at end-of-stream in reqAsync.runInAsyncScope()
so that the 'end' event preserves the correct AsyncLocalStorage context.

Refs: https://github.com/nodejs/node/pull/55460
Signed-off-by: Orgad Shaneh <orgad.shaneh@audiocodes.com>
PR-URL: https://github.com/nodejs/node/pull/63814
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

lib/internal/http2/core.js

@@ -483,7 +483,11 @@ function onSessionHeaders(handle, id, cat, flags, headers, sensitiveHeaders) {
     }
   }
   if (endOfStream) {
-    stream.push(null);
+    const reqAsync = stream[kRequestAsyncResource];
+    if (reqAsync)
+      reqAsync.runInAsyncScope(() => stream.push(null));
+    else
+      stream.push(null);
   }
 }
 

test/parallel/test-http2-async-local-storage.js

@@ -10,46 +10,56 @@ const async_hooks = require('async_hooks');
 const storage = new async_hooks.AsyncLocalStorage();
 
 const {
-  HTTP2_HEADER_CONTENT_TYPE,
   HTTP2_HEADER_PATH,
   HTTP2_HEADER_STATUS,
 } = http2.constants;
 
-const server = http2.createServer();
-server.on('stream', (stream) => {
-  stream.respond({
-    [HTTP2_HEADER_CONTENT_TYPE]: 'text/plain; charset=utf-8',
-    [HTTP2_HEADER_STATUS]: 200
-  });
-  stream.on('error', common.mustNotCall());
+function runTest(serverHandler) {
+  const server = http2.createServer();
+  server.on('stream', serverHandler);
+
+  server.listen(0, common.mustCall(() => {
+    const client = storage.run({ id: 0 }, () =>
+      http2.connect(`http://localhost:${server.address().port}`));
+
+    let ended = 0;
+    function doReq(id) {
+      const req = client.request({ [HTTP2_HEADER_PATH]: '/' });
+
+      req.on('response', common.mustCall((headers) => {
+        assert.strictEqual(headers[HTTP2_HEADER_STATUS], 200);
+        assert.strictEqual(storage.getStore().id, id);
+      }));
+      req.on('data', common.mustCall(() => {
+        assert.strictEqual(storage.getStore().id, id);
+      }));
+      req.on('end', common.mustCall(() => {
+        assert.strictEqual(storage.getStore().id, id);
+        if (++ended === 2) {
+          server.close();
+          client.close();
+        }
+      }));
+    }
+
+    storage.run({ id: 1 }, () => doReq(1));
+    storage.run({ id: 2 }, () => doReq(2));
+  }));
+}
+
+// Response without trailers: END_STREAM on the DATA frame.
+runTest((stream) => {
+  stream.respond({ [HTTP2_HEADER_STATUS]: 200 });
   stream.end('data');
 });
 
-server.listen(0, common.mustCall(async () => {
-  const client = storage.run({ id: 0 }, () => http2.connect(`http://localhost:${server.address().port}`));
-
-  async function doReq(id) {
-    const req = client.request({ [HTTP2_HEADER_PATH]: '/' });
-
-    req.on('response', common.mustCall((headers) => {
-      assert.strictEqual(headers[HTTP2_HEADER_STATUS], 200);
-      assert.strictEqual(id, storage.getStore().id);
-    }));
-    req.on('data', common.mustCall((data) => {
-      assert.strictEqual(data.toString(), 'data');
-      assert.strictEqual(id, storage.getStore().id);
-    }));
-    req.on('end', common.mustCall(() => {
-      assert.strictEqual(id, storage.getStore().id);
-      server.close();
-      client.close();
-    }));
-  }
-
-  function doReqWith(id) {
-    storage.run({ id }, () => doReq(id));
-  }
-
-  doReqWith(1);
-  doReqWith(2);
-}));
+// Response with trailers (as gRPC uses): END_STREAM on the trailing HEADERS
+// frame. The 'end' event must still run in the request's context.
+runTest((stream) => {
+  stream.respond({ [HTTP2_HEADER_STATUS]: 200 }, { waitForTrailers: true });
+  stream.on('wantTrailers', () => {
+    stream.sendTrailers({ 'grpc-status': '0' });
+  });
+  stream.write('data');
+  stream.end();
+});