Merge pull request #1037 from murgatroid99/grpc-js_client_error_construction

Add function for creating errors from statuses

packages/grpc-js/src/call.ts

@@ -68,6 +68,20 @@ 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 {
+  const message = `${status.code} ${Status[status.code]}: ${status.details}`;
+  return Object.assign(
+    new Error(message),
+    status
+  );
+}
+
 export class ClientUnaryCallImpl extends EventEmitter
   implements ClientUnaryCall {
   constructor(private readonly call: Call) {
@@ -118,11 +132,7 @@ function setUpReadableStream<ResponseType>(
   });
   call.on('status', (status: StatusObject) => {
     if (status.code !== Status.OK) {
-      const error: ServiceError = Object.assign(
+      stream.emit('error', callErrorFromStatus(status));
-        new Error(status.details),
-        status
-      );
-      stream.emit('error', error);
     }
     stream.emit('status', status);
     statusEmitted = true;

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';
@@ -151,11 +152,7 @@ export class Client {
       if (status.code === Status.OK) {
         callback(null, responseMessage as ResponseType);
       } else {
-        const error: ServiceError = Object.assign(
+        callback(callErrorFromStatus(status));
-          new Error(status.details),
-          status
-        );
-        callback(error);
       }
     });
   }

packages/grpc-js/test/test-server-deadlines.ts

@@ -160,7 +160,6 @@ describe('Cancellation', () => {
     call.on('error', (error: ServiceError) => {
       assert.strictEqual(error.code, grpc.status.CANCELLED);
       assert.strictEqual(error.details, 'Cancelled on client');
-      assert.strictEqual(error.message, 'Cancelled on client');
       waitForServerCancel();
     });