From 46c84bdb4ef87969e370ff9b39c542a78b58d746 Mon Sep 17 00:00:00 2001
From: Michael Lumish <mlumish@google.com>
Date: Tue, 7 Jul 2020 10:51:42 -0700
Subject: [PATCH] grpc-js: Improve error handling in a few places

---
 packages/grpc-js/package.json       |  2 +-
 packages/grpc-js/src/call-stream.ts |  9 +++++++++
 packages/grpc-js/src/subchannel.ts  | 27 +++++++++++++++++++++++++--
 3 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/packages/grpc-js/package.json b/packages/grpc-js/package.json
index da8e28ae..27aa679c 100644
--- a/packages/grpc-js/package.json
+++ b/packages/grpc-js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@grpc/grpc-js",
-  "version": "1.1.1",
+  "version": "1.1.2",
   "description": "gRPC Library for Node - pure JS implementation",
   "homepage": "https://grpc.io/",
   "repository": "https://github.com/grpc/grpc-node/tree/master/packages/grpc-js",
diff --git a/packages/grpc-js/src/call-stream.ts b/packages/grpc-js/src/call-stream.ts
index 041f9651..825342a5 100644
--- a/packages/grpc-js/src/call-stream.ts
+++ b/packages/grpc-js/src/call-stream.ts
@@ -541,6 +541,15 @@ export class Http2CallStream implements Call {
             code = Status.PERMISSION_DENIED;
             details = 'Protocol not secure enough';
             break;
+          case http2.constants.NGHTTP2_INTERNAL_ERROR:
+            code = Status.INTERNAL;
+            /* This error code was previously handled in the default case, and
+             * there are several instances of it online, so I wanted to
+             * preserve the original error message so that people find existing
+             * information in searches, but also include the more recognizable
+             * "Internal server error" message. */
+            details = `Received RST_STREAM with code ${stream.rstCode} (Internal server error)`;
+            break;
           default:
             code = Status.INTERNAL;
             details = `Received RST_STREAM with code ${stream.rstCode}`;
diff --git a/packages/grpc-js/src/subchannel.ts b/packages/grpc-js/src/subchannel.ts
index bbaa1ce1..be72680e 100644
--- a/packages/grpc-js/src/subchannel.ts
+++ b/packages/grpc-js/src/subchannel.ts
@@ -309,7 +309,8 @@ export class Subchannel {
         };
         connectionOptions.servername = sslTargetNameOverride;
       } else {
-        const authorityHostname = splitHostPort(targetAuthority)?.host ?? 'localhost';
+        const authorityHostname =
+          splitHostPort(targetAuthority)?.host ?? 'localhost';
         // We want to always set servername to support SNI
         connectionOptions.servername = authorityHostname;
       }
@@ -413,6 +414,11 @@ export class Subchannel {
               KEEPALIVE_MAX_TIME_MS
             );
           }
+          trace(
+            this.subchannelAddress +
+              ' connection closed by GOAWAY with code ' +
+              errorCode
+          );
           this.transitionToState(
             [ConnectivityState.CONNECTING, ConnectivityState.READY],
             ConnectivityState.IDLE
@@ -661,7 +667,24 @@ export class Subchannel {
     headers[HTTP2_HEADER_METHOD] = 'POST';
     headers[HTTP2_HEADER_PATH] = callStream.getMethod();
     headers[HTTP2_HEADER_TE] = 'trailers';
-    const http2Stream = this.session!.request(headers);
+    let http2Stream: http2.ClientHttp2Stream;
+    /* In theory, if an error is thrown by session.request because session has
+     * become unusable (e.g. because it has received a goaway), this subchannel
+     * should soon see the corresponding close or goaway event anyway and leave
+     * READY. But we have seen reports that this does not happen
+     * (https://github.com/googleapis/nodejs-firestore/issues/1023#issuecomment-653204096)
+     * so for defense in depth, we just discard the session when we see an
+     * error here.
+     */
+    try {
+      http2Stream = this.session!.request(headers);
+    } catch (e) {
+      this.transitionToState(
+        [ConnectivityState.READY],
+        ConnectivityState.TRANSIENT_FAILURE
+      );
+      throw e;
+    }
     let headersString = '';
     for (const header of Object.keys(headers)) {
       headersString += '\t\t' + header + ': ' + headers[header] + '\n';