grpc-js: Don't propagate non-numeric errors from auth plugins

packages/grpc-js/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@grpc/grpc-js",
-  "version": "1.2.7",
+  "version": "1.2.8",
   "description": "gRPC Library for Node - pure JS implementation",
   "homepage": "https://grpc.io/",
   "repository": "https://github.com/grpc/grpc-node/tree/master/packages/grpc-js",

packages/grpc-js/src/call-credentials-filter.ts

@@ -21,6 +21,7 @@ import { BaseFilter, Filter, FilterFactory } from './filter';
 import { Metadata } from './metadata';
 import { Status } from './constants';
 import { splitHostPort } from './uri-parser';
+import { ServiceError } from './call';
 
 export class CallCredentialsFilter extends BaseFilter implements Filter {
   private serviceUrl: string;
@@ -51,12 +52,21 @@ export class CallCredentialsFilter extends BaseFilter implements Filter {
       service_url: this.serviceUrl,
     });
     const resultMetadata = await metadata;
-    resultMetadata.merge(await credsMetadata);
+    try {
+      resultMetadata.merge(await credsMetadata);
+    } catch (error) {
+      this.stream.cancelWithStatus(
+        Status.UNAUTHENTICATED,
+        `Failed to retrieve auth metadata with error: ${error.message}`
+      );
+      return Promise.reject<Metadata>('Failed to retrieve auth metadata');
+    }
     if (resultMetadata.get('authorization').length > 1) {
       this.stream.cancelWithStatus(
         Status.INTERNAL,
         '"authorization" metadata cannot have multiple values'
       );
+      return Promise.reject<Metadata>('"authorization" metadata cannot have multiple values');
     }
     return resultMetadata;
   }

packages/grpc-js/src/channel.ts

@@ -384,7 +384,7 @@ export class ChannelImplementation implements Channel {
               (error: Error & { code: number }) => {
                 // We assume the error code isn't 0 (Status.OK)
                 callStream.cancelWithStatus(
-                  error.code || Status.UNKNOWN,
+                  (typeof error.code === 'number') ? error.code : Status.UNKNOWN,
                   `Getting metadata from plugin failed with error: ${error.message}`
                 );
               }