Using Grunt to Mock Endpoints - rest

Question

I'm using Yeoman, Grunt, and Bower, to construct a platform for building a frontend independently of a a backend. The idea would be that all of my (AngularJS) controller, services, factories, etc live in this project, and get injected afterwards into my serverside codebase based off the result of grunt build.
My question is:
How can I mock endpoints so that the Grunt server responds to the same endpoints as my (Rails) App will?
At the moment I am using:
angular.module('myApp', ['ngResource'])
.run(['$rootScope', function ($rootScope) {
$rootScope.testState = 'test';
}]);
And then in each of my individual services:
mockJSON = {'foo': 'myMockJSON'}
And on every method:
if($rootScope.testState == 'test'){
return mockJSON;
}
else {
real service logic with $q/$http goes here
}
Then after grunt build, testState = 'test' gets removed.
This is clearly a relatively janky architecture. How can I avoid it? How can I have Grunt respond to the same endpoints as my app (some of which have dynamic params) apply some logic (if necessary), and serve out a json file (possibly dependent on path params)?

Answer 1

I've fixed this issue by using express to write a server that responds with static json.
First I created a directory in my project called 'api'. Within that directory I have the following files:
package.json:
{
"name": "mockAPI",
"version": "0.0.0",
"dependencies": {
"express": "~3.3.4"
}
}
Then I run npm install in this directory.
index.js:
module.exports = require('./lib/server');
lib/server.js:
express = require('express');
var app = express();
app.get('/my/endpoint', function(req, res){
res.json({'foo': 'myMockJSON'});
});
module.exports = app
and finally in my global Gruntfile.js:
connect: {
options: {
port: 9000,
hostname: 'localhost',
},
livereload: {
options: {
middleware: function (connect, options) {
return [
lrSnippet,
mountFolder(connect, '.tmp'),
mountFolder(connect, yeomanConfig.app),
require('./api')
];
}
}
},
Then the services make the requests, and the express server serves the correct JSON.
After grunt build, the express server is simply replaced by a rails server.

Answer 2

As of grunt-contrib-connect v.0.7.0 you can also just add your custom middleware to the existing middleware stack without having to manually rebuild the existing middleware stack.
livereload: {
options: {
open: true,
base: [
'.tmp',
'<%= config.app %>'
],
middleware: function(connect, options, middlewares) {
// inject a custom middleware into the array of default middlewares
middlewares.push(function(req, res, next) {
if (req.url !== '/my/endpoint') {
return next();
}
res.writeHead(200, {'Content-Type': 'application/json' });
res.end("{'foo': 'myMockJSON'}");
});
return middlewares;
}
}
},
See https://github.com/gruntjs/grunt-contrib-connect#middleware for the official documentation.

Answer 3

Alternatively you can use the grunt-connect-proxy to proxy everything that is missing in your test server to an actual backend.
It's quite easy to install, just one thing to remember when adding proxy to your livereload connect middleware is to add it last, like this:
middleware: function (connect) {
return [
lrSnippet,
mountFolder(connect, '.tmp'),
mountFolder(connect, yeomanConfig.app),
proxySnippet
];
}

Answer 4

grunt-connect-prism is similar to the Ruby project VCR. It provides an easy way for front end developers to record HTTP responses returned by their API (or some other remote source) and replay them later. It's basically an HTTP cache, but for developers working on a Single Page Application (SPA). You can also generate stubs for API calls that don't exist, and populate them the way you want.
It's useful for mocking complex & high latency API calls during development. It's also useful when writing e2e tests for your SPA only, removing the server from the equation. This results in much faster execution of your e2e test suite.
Prism works by adding a custom connect middleware to the connect server provided by the grunt-contrib-connect plugin. While in 'record' mode it will generate a file per response on the filesystem with content like the following:
{
"requestUrl": "/api/ponies",
"contentType": "application/json",
"statusCode": 200,
"data": {
"text": "my little ponies"
}
}
DISCLAIMER: I'm the author of this project.

Answer 5

You can use Apache proxy and connect your REST server with gruntjs.
Apache would do this:
proxy / -> gruntjs
proxy /service -> REST server
you would use your application hitting Apache and angular.js application would think that is talking with itself so no cross domain problem.
Here is a great tutorial on how to set this up:
http://alfrescoblog.com/2014/06/14/angular-js-activiti-webapp-with-activiti-rest/

Answer 6

Just my alternative way that based on Abraham P's answer. It does not need to install express within 'api' folder. I can separate the mock services for certain files. For example, my 'api' folder contains 3 files:
api\
index.js // assign all the "modules" and then simply require that.
user.js // all mocking for user
product.js // all mocking for product
file user.js
var user = function(req, res, next) {
if (req.method === 'POST' && req.url.indexOf('/user') === 0) {
res.end(
JSON.stringify({
'id' : '5463c277-87c4-4f1d-8f95-7d895304de12',
'role' : 'admin'
})
);
}
else {
next();
}
}
module.exports = user;
file product.js
var product = function(req, res, next) {
if (req.method === 'POST' && req.url.indexOf('/product') === 0) {
res.end(
JSON.stringify({
'id' : '5463c277-87c4-4f1d-8f95-7d895304de12',
'name' : 'test',
'category': 'test'
})
);
}
else {
next();
}
}
module.exports = product;
index.js just assigns all the "modules" and we simply require that.
module.exports = {
product: require('./product.js'),
user: require('./user.js')
};
My Gruntfile.js file
connect: {
options: {
port: 9000,
// Change this to '0.0.0.0' to access the server from outside.
hostname: 'localhost',
livereload: 35729
},
livereload: {
options: {
open: true,
middleware: function (connect) {
return [
connect.static('.tmp'),
connect().use(
'/bower_components',
connect.static('./bower_components')
),
connect.static(appConfig.app),
require('./api').user,
require('./api').product,
];
}
}
}