How to run mocha tests and node in a single npm test command ? (CI) - node.js

Question

I want to use Circle CI to integrate a git project.
I'm using mocha for my tests .
What i want to do?
When running npm test I want:
my node server to start
my test file to run
How can I run a single npm test command to run both node and my mocha tests which are already wrapped in a single index.js file.
I have tried this in my package.json:
"scripts": {
"test": "node server/app.js & mocha server/tests/index.js",
"start": "node server/app.js",
"postinstall": "bower install"
}
The problems with the above
My server takes some time to start and the tests fail since they run before the server starts
Is there a standard way to run a server and the tests with a single command but I'm missing something?

Answer 1

If it is possible at all in your case I'd suggest using something like supertest to do the testing. This way, you can avoid having to start a server before starting the test.
I understand that there are scenarios where using supertest is not possible. In such case, you could poll your server in a before hook before all tests to wait until it is ready:
before(function (done) {
// Set a reasonable timeout for this hook.
this.timeout(5000);
function check() {
if (serverIsReady()) {
done();
return;
}
// The server is no ready, check again in 1/10th of a second.
setTimeout(check, 100);
}
check(); // Start checking.
});
I'm not sure what serverIsReady should be precisely in your case. It could be an attempt at getting a trivial path from your server like issuing a GET on the path /.

Answer 2

I think the key is to run your node server in your test, rather than trying to initialise it in another process.
Your mocha test should start with a require to your app, then each
of your tests can interact with it.
For example:
var http = require('http');
var server = http.createServer(function(req, res){
res.end('Hello World\n');
})
server.listen(8888);
describe('http', function(){
it('should provide an example', function(done){
http.get({ path: '/', port: 8888 }, function(res){
expect(res).to.have.property('statusCode', 200);
done();
})
})
})

Answer 3

What I do when running a test that needs certain pre-requisites is use mochas beforeEach() functionality.
From the documentation
You may also pick any file and add “root”-level hooks. For example, add beforeEach() outside of all describe() blocks. This will cause the callback to beforeEach() to run before any test case, regardless of the file it lives in (this is because Mocha has an implied describe() block, called the “root suite”).
beforeEach(function() {
console.log('before every test in every file');
});
In the before each code block you can run your command to start the server
using for example the exec library from npm
https://www.npmjs.com/package/exec
This will ensure your server is running before your tests are run allowing you to simply run npm test.