Add test case for function node template (#68)

Author: kazuhitoyokoi

Gruntfile.js

@@ -40,6 +40,9 @@ module.exports = function (grunt) {
             generateNode_sendReturnedMessage: {
                 command: 'node bin/node-red-nodegen.js samples/send-returned-message.js -o ./nodegen'
             },
+            generateNode_passThroughTopic: {
+                command: 'node bin/node-red-nodegen.js samples/pass-through-topic.js -o ./nodegen'
+            },
             generateNode_setNodeContext: {
                 command: 'node bin/node-red-nodegen.js samples/set-node-context.js -o ./nodegen'
             },

samples/pass-through-topic.js

@@ -0,0 +1,3 @@
+// name: pass through _topic
+// outputs: 1
+return msg;

test/nodegen/node-red-contrib-pass-through-topic/node_spec.js

@@ -0,0 +1,58 @@
+/**
+ * Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+var should = require("should");
+var helper = require("node-red-node-test-helper");
+var functionNode = require("../../../nodegen/node-red-contrib-pass-through-topic");
+
+describe('node-red-contrib-pass-through-topic', function () {
+
+    before(function (done) {
+        helper.startServer(done);
+    });
+
+    after(function (done) {
+        helper.stopServer(done);
+    });
+
+    afterEach(function () {
+        helper.unload();
+    });
+
+    it('should be loaded', function (done) {
+        var flow = [{id: "n1", type: "pass-through-topic", name: "pass-through-topic" }];
+        helper.load(functionNode, flow, function () {
+            var n1 = helper.getNode('n1');
+            n1.should.have.property('name', 'pass-through-topic');
+            done();
+        });
+    });
+    it('should pass through _topic', function (done) {
+        var flow = [{id: "n1", type: "pass-through-topic", wires: [["n2"]]},
+                    {id: "n2", type: "helper"}];
+        helper.load(functionNode, flow, function () {
+            var n1 = helper.getNode("n1");
+            var n2 = helper.getNode("n2");
+            n2.on("input", function(msg) {
+                msg.should.have.property('topic', 'bar');
+                msg.should.have.property('payload', 'foo');
+                msg.should.have.property('_topic', 'baz');
+                done();
+            });
+            n1.receive({payload: "foo", topic: "bar", _topic: "baz"});
+        });
+    });
+});