Mocha test runner (grunt-mocha-test) require timing issues

Question

I'm using the grunt-mocha-test package to run my unit tests in Node. Here's how the config object for grunt-mocha-test looks in my gruntfile:

mochaTest: {
  src: watchFiles.serverTests,
  options: {
    reporter: 'spec',
    require: 'server.js'
  }
}

watchFiles.serverTests is an array of file paths. server.js bootstraps my app. In server.js , I have something like the following:

var db = mongoose.connect(config.db, function(err) {
  // Setup express, etc. here
  // Set module exports
});

Previously, that looked something like this:

var db = mongoose.connect(config.db);
// Setup express, etc. here (some of which reference db)
// Set module exports

The problem was that Express needed the database connection to be successfully in order for it to initialize properly. Without the async database connection, I was getting some strange errors. So, I switched to the async setup. Now, however, when I require server.js with the async calls inside, the test runner fires off the Mocha tests before the app is completely fired up. Because of this, I need to find a happy medium along these lines:

var db = mongoose.connect(config.db, function(err) {
  // Setup express, etc. here
  // Set module exports
});

// Do something here that waits for the above to complete,
// so that the module is loaded synchronously.

As an alternative, I can pass a function to the mochaTest config object. Is there a way I could create this behavior there?

Answer 1

You could use a before Function with the done -Callback. This will halt your tests until done is called. Inside the before -Function you can then listen on mongoose connected -Event. Something like this:

var mongoose = require('mongoose');

before(function(done){
   mongoose.connection.on('connected', done);
});

Then just place this before your first test.