js: Don't include params if method is called without arguments

js/src/mopidy.js

@@ -255,11 +255,12 @@ Mopidy.prototype._getApiSpec = function () {
 Mopidy.prototype._createApi = function (methods) {
     var caller = function (method) {
         return function () {
-            var params = Array.prototype.slice.call(arguments);
+            var message = {method: method};
-            return this._send({
+            if (arguments.length === 0) {
-                method: method,
+                return this._send(message);
-                params: params
+            }
-            });
+            message.params = Array.prototype.slice.call(arguments);
+            return this._send(message);
         }.bind(this);
     }.bind(this);
 

js/test/mopidy-test.js

@@ -767,28 +767,36 @@ buster.testCase("Mopidy", {
         },
 
         "by-position calling convention": {
+            setUp: function () {
+                this.mopidy._createApi({
+                    foo: {
+                        params: ["bar", "baz"]
+                    }
+                });
+                this.sendStub = this.stub(this.mopidy, "_send");
+
+            },
+
             "is the default": function () {
                 assert.equals(
                     this.mopidy._settings.callingConvention,
                     "by-position-only");
             },
 
-            "sends messages with function arguments unchanged": function () {
+            "sends no params if no arguments passed to function": function () {
-                var sendStub = this.stub(this.mopidy, "_send");
+                this.mopidy.foo();
-                this.mopidy._createApi({
-                    foo: {
-                        params: ["bar", "baz"]
-                    }
-                });
 
+                assert.calledOnceWith(this.sendStub, {method: "foo"});
+            },
+
+            "sends messages with function arguments unchanged": function () {
                 this.mopidy.foo(31, 97);
 
-                assert.calledOnceWith(sendStub, {
+                assert.calledOnceWith(this.sendStub, {
                     method: "foo",
                     params: [31, 97]
                 });
             },
         }
-
     }
 });