index.js

var casual = require('casual'),
    service = require('../real-service');

descibe('Some sort of service', function() {
	it('Should not fail', function() {
		var string = casual.string;
		var expected = string + 'A';

		var result = service.appendLetterAtoEndOfString(string);
		result.should.be.exactly(expected);
	});
});