always default to empty metadata

Author: stephenplusplus

packages/common/src/grpc-service.js

@@ -159,11 +159,9 @@ function GrpcService(config, options) {
     this.grpcCredentials = grpc.credentials.createInsecure();
   }
 
-  this.grpcMetadata = null;
+  this.grpcMetadata = new grpc.Metadata();
 
   if (config.grpcMetadata) {
-    this.grpcMetadata = new grpc.Metadata();
-
     for (var prop in config.grpcMetadata) {
       if (config.grpcMetadata.hasOwnProperty(prop)) {
         this.grpcMetadata.add(prop, config.grpcMetadata[prop]);

packages/common/test/grpc-service.js

@@ -241,11 +241,17 @@ describe('GrpcService', function() {
     });
 
     it('should default grpcMetadata to null', function() {
+      var fakeGrpcMetadata = {};
+
+      grpcMetadataOverride = function() {
+        return fakeGrpcMetadata;
+      };
+
       var config = extend({}, CONFIG);
       delete config.grpcMetadata;
 
       var grpcService = new GrpcService(config, OPTIONS);
-      assert.strictEqual(grpcService.grpcMetadata, null);
+      assert.strictEqual(grpcService.grpcMetadata, fakeGrpcMetadata);
     });
 
     it('should create and localize grpcMetadata', function() {