Follow Node's callback-last convention for client calls

package.json

@@ -27,6 +27,7 @@
   },
   "bundledDependencies": ["node-pre-gyp"],
   "dependencies": {
+    "arguejs": "^0.2.3",
     "lodash": "^3.9.3",
     "nan": "^2.0.0",
     "protobufjs": "^4.0.0"

src/node/interop/interop_client.js

@@ -286,7 +286,7 @@ function cancelAfterFirstResponse(client, done) {
 function timeoutOnSleepingServer(client, done) {
   var deadline = new Date();
   deadline.setMilliseconds(deadline.getMilliseconds() + 1);
-  var call = client.fullDuplexCall(null, {deadline: deadline});
+  var call = client.fullDuplexCall({deadline: deadline});
   call.write({
     payload: {body: zeroBuffer(27182)}
   });
@@ -316,10 +316,10 @@ function customMetadata(client, done) {
       body: zeroBuffer(271828)
     }
   };
-  var unary = client.unaryCall(arg, function(err, resp) {
+  var unary = client.unaryCall(arg, metadata, function(err, resp) {
     assert.ifError(err);
     done();
-  }, metadata);
+  });
   unary.on('metadata', function(metadata) {
     assert.deepEqual(metadata.get(ECHO_INITIAL_KEY),
                      ['test_initial_metadata_value']);
@@ -455,14 +455,14 @@ function perRpcAuthTest(client, done, extra) {
       credential = credential.createScoped(scope);
     }
     var creds = grpc.credentials.createFromGoogleCredential(credential);
-    client.unaryCall(arg, function(err, resp) {
+    client.unaryCall(arg, {credentials: creds}, function(err, resp) {
       assert.ifError(err);
       assert.strictEqual(resp.username, SERVICE_ACCOUNT_EMAIL);
       assert(extra.oauth_scope.indexOf(resp.oauth_scope) > -1);
       if (done) {
         done();
       }
-    }, null, {credentials: creds});
+    });
   });
 }
 

src/node/src/client.js

@@ -50,6 +50,7 @@
 'use strict';
 
 var _ = require('lodash');
+var arguejs = require('arguejs');
 
 var grpc = require('./grpc_extension');
 
@@ -353,21 +354,23 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
    * @this {Client} Client object. Must have a channel member.
    * @param {*} argument The argument to the call. Should be serializable with
    *     serialize
-   * @param {function(?Error, value=)} callback The callback to for when the
-   *     response is received
    * @param {Metadata=} metadata Metadata to add to the call
    * @param {Object=} options Options map
+   * @param {function(?Error, value=)} callback The callback to for when the
+   *     response is received
    * @return {EventEmitter} An event emitter for stream related events
    */
-  function makeUnaryRequest(argument, callback, metadata, options) {
+  function makeUnaryRequest(argument, metadata, options, callback) {
     /* jshint validthis: true */
+    /* While the arguments are listed in the function signature, those variables
+     * are not used directly. Instead, ArgueJS processes the arguments
+     * object. This allows for simple handling of optional arguments in the
+     * middle of the argument list, and also provides type checking. */
+    var args = arguejs({argument: null, metadata: [Metadata, new Metadata()],
+                        options: [Object], callback: Function}, arguments);
     var emitter = new EventEmitter();
-    var call = getCall(this.$channel, method, options);
-    if (metadata === null || metadata === undefined) {
-      metadata = new Metadata();
-    } else {
-      metadata = metadata.clone();
-    }
+    var call = getCall(this.$channel, method, args.options);
+    metadata = args.metadata.clone();
     emitter.cancel = function cancel() {
       call.cancel();
     };
@@ -375,9 +378,9 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
       return call.getPeer();
     };
     var client_batch = {};
-    var message = serialize(argument);
-    if (options) {
-      message.grpcWriteFlags = options.flags;
+    var message = serialize(args.argument);
+    if (args.options) {
+      message.grpcWriteFlags = args.options.flags;
     }
     client_batch[grpc.opType.SEND_INITIAL_METADATA] =
         metadata._getCoreRepresentation();
@@ -395,7 +398,7 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
       if (status.code === grpc.status.OK) {
         if (err) {
           // Got a batch error, but OK status. Something went wrong
-          callback(err);
+          args.callback(err);
           return;
         } else {
           try {
@@ -414,9 +417,9 @@ function makeUnaryRequestFunction(method, serialize, deserialize) {
         error = new Error(status.details);
         error.code = status.code;
         error.metadata = status.metadata;
-        callback(error);
+        args.callback(error);
       } else {
-        callback(null, deserialized);
+        args.callback(null, deserialized);
       }
       emitter.emit('status', status);
       emitter.emit('metadata', Metadata._fromCoreRepresentation(
@@ -440,21 +443,23 @@ function makeClientStreamRequestFunction(method, serialize, deserialize) {
    * Make a client stream request with this method on the given channel with the
    * given callback, etc.
    * @this {Client} Client object. Must have a channel member.
-   * @param {function(?Error, value=)} callback The callback to for when the
-   *     response is received
    * @param {Metadata=} metadata Array of metadata key/value pairs to add to the
    *     call
    * @param {Object=} options Options map
+   * @param {function(?Error, value=)} callback The callback to for when the
+   *     response is received
    * @return {EventEmitter} An event emitter for stream related events
    */
-  function makeClientStreamRequest(callback, metadata, options) {
+  function makeClientStreamRequest(metadata, options, callback) {
     /* jshint validthis: true */
-    var call = getCall(this.$channel, method, options);
-    if (metadata === null || metadata === undefined) {
-      metadata = new Metadata();
-    } else {
-      metadata = metadata.clone();
-    }
+    /* While the arguments are listed in the function signature, those variables
+     * are not used directly. Instead, ArgueJS processes the arguments
+     * object. This allows for simple handling of optional arguments in the
+     * middle of the argument list, and also provides type checking. */
+    var args = arguejs({metadata: [Metadata, new Metadata()],
+                        options: [Object], callback: Function}, arguments);
+    var call = getCall(this.$channel, method, args.options);
+    metadata = args.metadata.clone();
     var stream = new ClientWritableStream(call, serialize);
     var metadata_batch = {};
     metadata_batch[grpc.opType.SEND_INITIAL_METADATA] =
@@ -481,7 +486,7 @@ function makeClientStreamRequestFunction(method, serialize, deserialize) {
       if (status.code === grpc.status.OK) {
         if (err) {
           // Got a batch error, but OK status. Something went wrong
-          callback(err);
+          args.callback(err);
           return;
         } else {
           try {
@@ -500,9 +505,9 @@ function makeClientStreamRequestFunction(method, serialize, deserialize) {
         error = new Error(response.status.details);
         error.code = status.code;
         error.metadata = status.metadata;
-        callback(error);
+        args.callback(error);
       } else {
-        callback(null, deserialized);
+        args.callback(null, deserialized);
       }
       stream.emit('status', status);
     });
@@ -533,17 +538,18 @@ function makeServerStreamRequestFunction(method, serialize, deserialize) {
    */
   function makeServerStreamRequest(argument, metadata, options) {
     /* jshint validthis: true */
-    var call = getCall(this.$channel, method, options);
-    if (metadata === null || metadata === undefined) {
-      metadata = new Metadata();
-    } else {
-      metadata = metadata.clone();
-    }
+    /* While the arguments are listed in the function signature, those variables
+     * are not used directly. Instead, ArgueJS processes the arguments
+     * object. */
+    var args = arguejs({argument: null, metadata: [Metadata, new Metadata()],
+                        options: [Object]}, arguments);
+    var call = getCall(this.$channel, method, args.options);
+    metadata = args.metadata.clone();
     var stream = new ClientReadableStream(call, deserialize);
     var start_batch = {};
-    var message = serialize(argument);
-    if (options) {
-      message.grpcWriteFlags = options.flags;
+    var message = serialize(args.argument);
+    if (args.options) {
+      message.grpcWriteFlags = args.options.flags;
     }
     start_batch[grpc.opType.SEND_INITIAL_METADATA] =
         metadata._getCoreRepresentation();
@@ -595,12 +601,13 @@ function makeBidiStreamRequestFunction(method, serialize, deserialize) {
    */
   function makeBidiStreamRequest(metadata, options) {
     /* jshint validthis: true */
-    var call = getCall(this.$channel, method, options);
-    if (metadata === null || metadata === undefined) {
-      metadata = new Metadata();
-    } else {
-      metadata = metadata.clone();
-    }
+    /* While the arguments are listed in the function signature, those variables
+     * are not used directly. Instead, ArgueJS processes the arguments
+     * object. */
+    var args = arguejs({metadata: [Metadata, new Metadata()],
+                        options: [Object]}, arguments);
+    var call = getCall(this.$channel, method, args.options);
+    metadata = args.metadata.clone();
     var stream = new ClientDuplexStream(call, serialize, deserialize);
     var start_batch = {};
     start_batch[grpc.opType.SEND_INITIAL_METADATA] =

src/node/test/credentials_test.js

@@ -398,18 +398,20 @@ describe('client credentials', function() {
           metadataUpdater);
     });
     it('Should update metadata on a unary call', function(done) {
-      var call = client.unary({}, function(err, data) {
-        assert.ifError(err);
-      }, null, {credentials: updater_creds});
+      var call = client.unary({}, {credentials: updater_creds},
+                              function(err, data) {
+                                assert.ifError(err);
+                              });
       call.on('metadata', function(metadata) {
         assert.deepEqual(metadata.get('plugin_key'), ['plugin_value']);
         done();
       });
     });
     it('should update metadata on a client streaming call', function(done) {
-      var call = client.clientStream(function(err, data) {
-        assert.ifError(err);
-      }, null, {credentials: updater_creds});
+      var call = client.clientStream({credentials: updater_creds},
+                                     function(err, data) {
+                                       assert.ifError(err);
+                                     });
       call.on('metadata', function(metadata) {
         assert.deepEqual(metadata.get('plugin_key'), ['plugin_value']);
         done();
@@ -417,7 +419,7 @@ describe('client credentials', function() {
       call.end();
     });
     it('should update metadata on a server streaming call', function(done) {
-      var call = client.serverStream({}, null, {credentials: updater_creds});
+      var call = client.serverStream({}, {credentials: updater_creds});
       call.on('data', function() {});
       call.on('metadata', function(metadata) {
         assert.deepEqual(metadata.get('plugin_key'), ['plugin_value']);
@@ -425,7 +427,7 @@ describe('client credentials', function() {
       });
     });
     it('should update metadata on a bidi streaming call', function(done) {
-      var call = client.bidiStream(null, {credentials: updater_creds});
+      var call = client.bidiStream({credentials: updater_creds});
       call.on('data', function() {});
       call.on('metadata', function(metadata) {
         assert.deepEqual(metadata.get('plugin_key'), ['plugin_value']);
@@ -443,9 +445,10 @@ describe('client credentials', function() {
           altMetadataUpdater);
       var combined_updater = grpc.credentials.combineCallCredentials(
           updater_creds, alt_updater_creds);
-      var call = client.unary({}, function(err, data) {
-        assert.ifError(err);
-      }, null, {credentials: combined_updater});
+      var call = client.unary({}, {credentials: combined_updater},
+                              function(err, data) {
+                                assert.ifError(err);
+                              });
       call.on('metadata', function(metadata) {
         assert.deepEqual(metadata.get('plugin_key'), ['plugin_value']);
         assert.deepEqual(metadata.get('other_plugin_key'),

src/node/test/surface_test.js

@@ -404,18 +404,18 @@ describe('Echo metadata', function() {
     server.forceShutdown();
   });
   it('with unary call', function(done) {
-    var call = client.unary({}, function(err, data) {
+    var call = client.unary({}, metadata, function(err, data) {
       assert.ifError(err);
-    }, metadata);
+    });
     call.on('metadata', function(metadata) {
       assert.deepEqual(metadata.get('key'), ['value']);
       done();
     });
   });
   it('with client stream call', function(done) {
-    var call = client.clientStream(function(err, data) {
+    var call = client.clientStream(metadata, function(err, data) {
       assert.ifError(err);
-    }, metadata);
+    });
     call.on('metadata', function(metadata) {
       assert.deepEqual(metadata.get('key'), ['value']);
       done();
@@ -441,8 +441,8 @@ describe('Echo metadata', function() {
   });
   it('shows the correct user-agent string', function(done) {
     var version = require('../../../package.json').version;
-    var call = client.unary({}, function(err, data) { assert.ifError(err); },
-                            metadata);
+    var call = client.unary({}, metadata,
+                            function(err, data) { assert.ifError(err); });
     call.on('metadata', function(metadata) {
       assert(_.startsWith(metadata.get('user-agent')[0],
                           'grpc-node/' + version));
@@ -452,8 +452,8 @@ describe('Echo metadata', function() {
   it('properly handles duplicate values', function(done) {
     var dup_metadata = metadata.clone();
     dup_metadata.add('key', 'value2');
-    var call = client.unary({}, function(err, data) {assert.ifError(err); },
-                            dup_metadata);
+    var call = client.unary({}, dup_metadata,
+                            function(err, data) {assert.ifError(err); });
     call.on('metadata', function(resp_metadata) {
       // Two arrays are equal iff their symmetric difference is empty
       assert.deepEqual(_.xor(dup_metadata.get('key'), resp_metadata.get('key')),
@@ -954,7 +954,7 @@ describe('Call propagation', function() {
       done = multiDone(done, 2);
       var call;
       proxy_impl.unary = function(parent, callback) {
-        client.unary(parent.request, function(err, value) {
+        client.unary(parent.request, {parent: parent}, function(err, value) {
           try {
             assert(err);
             assert.strictEqual(err.code, grpc.status.CANCELLED);
@@ -962,7 +962,7 @@ describe('Call propagation', function() {
             callback(err, value);
             done();
           }
-        }, null, {parent: parent});
+        });
         call.cancel();
       };
       proxy.addProtoService(test_service, proxy_impl);
@@ -976,7 +976,7 @@ describe('Call propagation', function() {
       done = multiDone(done, 2);
       var call;
       proxy_impl.clientStream = function(parent, callback) {
-        client.clientStream(function(err, value) {
+        client.clientStream({parent: parent}, function(err, value) {
           try {
             assert(err);
             assert.strictEqual(err.code, grpc.status.CANCELLED);
@@ -984,7 +984,7 @@ describe('Call propagation', function() {
             callback(err, value);
             done();
           }
-        }, null, {parent: parent});
+        });
         call.cancel();
       };
       proxy.addProtoService(test_service, proxy_impl);
@@ -998,8 +998,7 @@ describe('Call propagation', function() {
       done = multiDone(done, 2);
       var call;
       proxy_impl.serverStream = function(parent) {
-        var child = client.serverStream(parent.request, null,
-                                        {parent: parent});
+        var child = client.serverStream(parent.request, {parent: parent});
         child.on('data', function() {});
         child.on('error', function(err) {
           assert(err);
@@ -1023,7 +1022,7 @@ describe('Call propagation', function() {
       done = multiDone(done, 2);
       var call;
       proxy_impl.bidiStream = function(parent) {
-        var child = client.bidiStream(null, {parent: parent});
+        var child = client.bidiStream({parent: parent});
         child.on('data', function() {});
         child.on('error', function(err) {
           assert(err);
@@ -1051,7 +1050,8 @@ describe('Call propagation', function() {
     it('With a client stream call', function(done) {
       done = multiDone(done, 2);
       proxy_impl.clientStream = function(parent, callback) {
-        client.clientStream(function(err, value) {
+        var options = {parent: parent, propagate_flags: deadline_flags};
+        client.clientStream(options, function(err, value) {
           try {
             assert(err);
             assert(err.code === grpc.status.DEADLINE_EXCEEDED ||
@@ -1060,7 +1060,7 @@ describe('Call propagation', function() {
             callback(err, value);
             done();
           }
-        }, null, {parent: parent, propagate_flags: deadline_flags});
+        });
       };
       proxy.addProtoService(test_service, proxy_impl);
       var proxy_port = proxy.bind('localhost:0', server_insecure_creds);
@@ -1069,15 +1069,15 @@ describe('Call propagation', function() {
                                     grpc.credentials.createInsecure());
       var deadline = new Date();
       deadline.setSeconds(deadline.getSeconds() + 1);
-      proxy_client.clientStream(function(err, value) {
+      proxy_client.clientStream({deadline: deadline}, function(err, value) {
         done();
-      }, null, {deadline: deadline});
+      });
     });
     it('With a bidi stream call', function(done) {
       done = multiDone(done, 2);
       proxy_impl.bidiStream = function(parent) {
         var child = client.bidiStream(
-            null, {parent: parent, propagate_flags: deadline_flags});
+            {parent: parent, propagate_flags: deadline_flags});
         child.on('data', function() {});
         child.on('error', function(err) {
           assert(err);
@@ -1093,7 +1093,7 @@ describe('Call propagation', function() {
                                     grpc.credentials.createInsecure());
       var deadline = new Date();
       deadline.setSeconds(deadline.getSeconds() + 1);
-      var call = proxy_client.bidiStream(null, {deadline: deadline});
+      var call = proxy_client.bidiStream({deadline: deadline});
       call.on('data', function() {});
       call.on('error', function(err) {
         done();

templates/package.json.template

@@ -29,6 +29,7 @@
     },
     "bundledDependencies": ["node-pre-gyp"],
     "dependencies": {
+      "arguejs": "^0.2.3",
       "lodash": "^3.9.3",
       "nan": "^2.0.0",
       "protobufjs": "^4.0.0"