unary request and client stream promise support

packages/grpc-native-core/index.d.ts

@@ -1089,8 +1089,8 @@ declare module "grpc" {
       argument: RequestType | null,
       metadata: Metadata | null,
       options: CallOptions | null,
-      callback: requestCallback<ResponseType>,
-    ): ClientUnaryCall;
+      callback?: requestCallback<ResponseType>,
+    ): ClientUnaryCall & PromiseLike<ResponseType>;
 
     /**
      * Make a client stream request to the given method, using the given serialize
@@ -1109,8 +1109,8 @@ declare module "grpc" {
       deserialize: deserialize<ResponseType>,
       metadata: Metadata | null,
       options: CallOptions | null,
-      callback: requestCallback<ResponseType>,
-    ): ClientWritableStream<RequestType>;
+      callback?: requestCallback<ResponseType>,
+    ): ClientWritableStream<RequestType> & PromiseLike<ResponseType>;
 
     /**
      * Make a server stream request to the given method, with the given serialize

packages/grpc-native-core/src/client.js

@@ -470,15 +470,22 @@ Client.prototype.makeUnaryRequest = function(path, serialize, deserialize,
     metadata = new Metadata();
     options = {};
   }
+  if (!callback && !options) {
+    if (metadata instanceof Metadata) {
+      options = {};
+    } else {
+      options = metadata;
+      metadata = new Metadata();
+    }
+  }
   if (!metadata) {
     metadata = new Metadata();
   }
   if (!options) {
     options = {};
   }
   if (!((metadata instanceof Metadata) &&
-        (options instanceof Object) &&
-        (typeof callback === 'function'))) {
+        (options instanceof Object))) {
     throw new Error('Argument mismatch in makeUnaryRequest');
   }
 
@@ -517,26 +524,47 @@ Client.prototype.makeUnaryRequest = function(path, serialize, deserialize,
     callOptions.interceptor_providers
   );
 
-  var intercepting_call = client_interceptors.getInterceptingCall(
-    methodDefinition,
-    callOptions,
-    interceptors,
-    callProperties.channel,
-    callProperties.callback
-  );
-
   var emitter = callProperties.call;
-  emitter.call = intercepting_call;
 
-  var last_listener = client_interceptors.getLastListener(
-    methodDefinition,
-    emitter,
-    callProperties.callback
-  );
+  var promise = new Promise((resolve, reject) => {
+    var promise_callback = function (err, data) {
+      if (typeof callProperties.callback === 'function') {
+        callProperties.callback.apply(this, [err, data]);
+      }
+
+      if (err) {
+        return reject(err);
+      }
+      resolve(data);
+    };
 
-  intercepting_call.start(callProperties.metadata, last_listener);
-  intercepting_call.sendMessage(callProperties.argument);
-  intercepting_call.halfClose();
+    var intercepting_call = client_interceptors.getInterceptingCall(
+      methodDefinition,
+      callOptions,
+      interceptors,
+      callProperties.channel,
+      promise_callback
+    );
+
+    emitter.call = intercepting_call;
+
+    var last_listener = client_interceptors.getLastListener(
+      methodDefinition,
+      emitter,
+      promise_callback
+    );
+
+    intercepting_call.start(callProperties.metadata, last_listener);
+    intercepting_call.sendMessage(callProperties.argument);
+    intercepting_call.halfClose();
+  });
+
+  if (typeof callProperties.callback === 'function') {
+    // avoid UnhandledPromiseRejectionWarning
+    promise.catch(() => {});
+  }
+
+  emitter.then = promise.then.bind(promise);
 
   return emitter;
 };
@@ -573,15 +601,22 @@ Client.prototype.makeClientStreamRequest = function(path, serialize,
     metadata = new Metadata();
     options = {};
   }
+  if (!callback && !options) {
+    if (metadata instanceof Metadata) {
+      options = {};
+    } else {
+      options = metadata;
+      metadata = new Metadata();
+    }
+  }
   if (!metadata) {
     metadata = new Metadata();
   }
   if (!options) {
     options = {};
   }
   if (!((metadata instanceof Metadata) &&
-       (options instanceof Object) &&
-       (typeof callback === 'function'))) {
+       (options instanceof Object))) {
     throw new Error('Argument mismatch in makeClientStreamRequest');
   }
 
@@ -619,24 +654,45 @@ Client.prototype.makeClientStreamRequest = function(path, serialize,
     callOptions.interceptor_providers
   );
 
-  var intercepting_call = client_interceptors.getInterceptingCall(
-    methodDefinition,
-    callOptions,
-    interceptors,
-    callProperties.channel,
-    callProperties.callback
-  );
-
   var emitter = callProperties.call;
-  emitter.call = intercepting_call;
 
-  var last_listener = client_interceptors.getLastListener(
-    methodDefinition,
-    emitter,
-    callProperties.callback
-  );
+  var promise = new Promise((resolve, reject) => {
+    var promise_callback = function (err, data) {
+      if (typeof callProperties.callback === 'function') {
+        callProperties.callback.apply(this, [err, data]);
+      }
+
+      if (err) {
+        return reject(err);
+      }
+      resolve(data);
+    };
 
-  intercepting_call.start(callProperties.metadata, last_listener);
+    var intercepting_call = client_interceptors.getInterceptingCall(
+      methodDefinition,
+      callOptions,
+      interceptors,
+      callProperties.channel,
+      promise_callback
+    );
+
+    emitter.call = intercepting_call;
+
+    var last_listener = client_interceptors.getLastListener(
+      methodDefinition,
+      emitter,
+      promise_callback
+    );
+
+    intercepting_call.start(callProperties.metadata, last_listener);
+  });
+
+  if (typeof callProperties.callback === 'function') {
+    // avoid UnhandledPromiseRejectionWarning
+    promise.catch(() => {});
+  }
+
+  emitter.then = promise.then.bind(promise);
 
   return emitter;
 };

packages/grpc-native-core/test/client_interceptors_test.js

@@ -193,6 +193,21 @@ describe('Client interceptors', function() {
         echoBidiStream: []
       }));
     });
+    it('with unary call and promise', function(done) {
+      var expected_value = 'foo';
+      var message = {value: expected_value};
+      client.echo(message)
+        .then(function(response) {
+          assert.strictEqual(response.value, expected_value);
+          done();
+        });
+      assert(_.isEqual(grpc_client.getClientInterceptors(client), {
+        echo: [],
+        echoClientStream: [],
+        echoServerStream: [],
+        echoBidiStream: []
+      }));
+    });
   });
 
   describe('execute downstream interceptors when a new call is made outbound',
@@ -288,6 +303,16 @@ describe('Client interceptors', function() {
         stream.write(message);
         stream.end();
       });
+      it('with client streaming call with promise', function(done) {
+        registry = new CallRegistry(done, expected_calls, false);
+        var message = { value: 'foo' };
+        var stream = client.echoClientStream(options);
+        stream.write(message);
+        stream.end().then(function (res) {
+          assert.strictEqual(res.value, message.value);
+          registry.addCall('response');
+        });
+      });
       it('with server streaming call', function(done) {
         registry = new CallRegistry(done, expected_calls, true);
         var message = {};