grpc: listen for metadata event instead of status

lib/common/grpc-service.js

@@ -325,7 +325,8 @@ GrpcService.prototype.requestStream = function(protoOpts, reqOpts) {
 
     request: function() {
       return service[protoOpts.method](reqOpts, grpcOpts)
-        .on('status', function(status) {
+        .on('metadata', function() {
+          var status = this.received_status || { code: 0 };
           var grcpStatus = GrpcService.decorateStatus_(status);
 
           this.emit('response', grcpStatus || status);

test/common/grpc-service.js

@@ -1062,7 +1062,7 @@ describe('GrpcService', function() {
         );
       });
 
-      it('should emit the status as a response event', function(done) {
+      it('should emit the metadata event as a response event', function(done) {
         var grpcError500 = { code: 2 };
         var fakeStream = through.obj();
 
@@ -1074,14 +1074,37 @@ describe('GrpcService', function() {
           return options.request();
         };
 
+        fakeStream.received_status = grpcError500;
+
         fakeStream
           .on('response', function(resp) {
             assert.deepEqual(resp, GrpcService.GRPC_ERROR_CODE_TO_HTTP[2]);
             done();
           });
 
         grpcService.requestStream(PROTO_OPTS, REQ_OPTS);
-        fakeStream.emit('status', grpcError500);
+        fakeStream.emit('metadata');
+      });
+
+      it('should default to OK status when metadata fires', function(done) {
+        var fakeStream = through.obj();
+
+        ProtoService.prototype.method = function() {
+          return fakeStream;
+        };
+
+        retryRequestOverride = function(reqOpts, options) {
+          return options.request();
+        };
+
+        fakeStream
+          .on('response', function(resp) {
+            assert.deepEqual(resp, GrpcService.GRPC_ERROR_CODE_TO_HTTP[0]);
+            done();
+          });
+
+        grpcService.requestStream(PROTO_OPTS, REQ_OPTS);
+        fakeStream.emit('metadata');
       });
 
       it('should emit the response error', function(done) {