From b003aa14d4a13e1fc1e446ced124649706d9138e Mon Sep 17 00:00:00 2001
From: murgatroid99 <mlumish@google.com>
Date: Thu, 19 Sep 2019 17:14:38 -0700
Subject: [PATCH] Add function for creating errors from statuses

---
 packages/grpc-js/src/call.ts   | 19 ++++++++++++++-----
 packages/grpc-js/src/client.ts |  7 ++-----
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/packages/grpc-js/src/call.ts b/packages/grpc-js/src/call.ts
index 2f45b82f..e6127faa 100644
--- a/packages/grpc-js/src/call.ts
+++ b/packages/grpc-js/src/call.ts
@@ -68,6 +68,19 @@ export type ClientDuplexStream<
   ResponseType
 > = ClientWritableStream<RequestType> & ClientReadableStream<ResponseType>;
 
+/**
+ * Construct a ServiceError from a StatusObject. This function exists primarily
+ * as an attempt to make the error stack trace clearly communicate that the
+ * error is not necessarily a problem in gRPC itself.
+ * @param status 
+ */
+export function callErrorFromStatus(status: StatusObject): ServiceError {
+  return Object.assign(
+    new Error(status.details),
+    status
+  );
+}
+
 export class ClientUnaryCallImpl extends EventEmitter
   implements ClientUnaryCall {
   constructor(private readonly call: Call) {
@@ -118,11 +131,7 @@ function setUpReadableStream<ResponseType>(
   });
   call.on('status', (status: StatusObject) => {
     if (status.code !== Status.OK) {
-      const error: ServiceError = Object.assign(
-        new Error(status.details),
-        status
-      );
-      stream.emit('error', error);
+      stream.emit('error', callErrorFromStatus(status));
     }
     stream.emit('status', status);
     statusEmitted = true;
diff --git a/packages/grpc-js/src/client.ts b/packages/grpc-js/src/client.ts
index a092e61d..fc145942 100644
--- a/packages/grpc-js/src/client.ts
+++ b/packages/grpc-js/src/client.ts
@@ -25,6 +25,7 @@ import {
   ClientWritableStream,
   ClientWritableStreamImpl,
   ServiceError,
+  callErrorFromStatus,
 } from './call';
 import { CallCredentials } from './call-credentials';
 import { Call, Deadline, StatusObject, WriteObject } from './call-stream';
@@ -147,11 +148,7 @@ export class Client {
       if (status.code === Status.OK) {
         callback(null, responseMessage as ResponseType);
       } else {
-        const error: ServiceError = Object.assign(
-          new Error(status.details),
-          status
-        );
-        callback(error);
+        callback(callErrorFromStatus(status));
       }
     });
   }