A simple library to spy on functions and create stubs for unit testing. Yes, there are many libraries that do this out there, but they're all tied to a specific assertion framework. Spies is not tied to any assertion frameworks. You can use any assertion frameworks you want, though it comes with a plugin for Chai expect (and possibly more in the future).
Go here for the complete API.
To use this, HTML import the main.html file.
Spies watch over function calls. When writing unit tests, spy on functions that you are interested in watching. For example:
/**
* Source Code
*/
IceCream = function() {};
IceCream.prototype.scoop = function() {};
Person = function() {};
Person.prototype.iceCream = new IceCream();
Person.prototype.eatIceCream = function(amount) {
iceCream.scoop(amount);
};
/**
* Test Code
*/
var _ = spies.Spies;
var person = new Person();
_.spy(person.iceCream, 'scoop');
person.eatIceCream(2);
expect(_.callCountOf(person.iceCream.scoop)(2)).to.be.equal(1);
_.reset(); // Resets all spied functions.To ignore any arguments, use anyCallCountOf:
_.spy(person.iceCream, 'scoop');
person.eatIceCream(1);
person.eatIceCream(3);
expect(_.anyCallCountOf(person.iceCream.scoop)).to.be.equal(2);
_.reset();You can relax the matching condition by using Matcher objects:
var _M = spies.Matchers;
_.spy(person.iceCream, 'scoop');
person.eatIceCream(1);
person.eatIceCream('gallon');
expect(_.callCountOf(person.iceCream.scoop)(Matchers.isA('number'))).to.be.equal(1);
_.reset();You can also get the matched arguments by calling matchingArgs on the matcher object. This is
very useful for getting event handlers:
/**
* Source Code
*/
var object = {
fn: function() {};
};
var handler = function() {
object.fn();
};
var f = function() {
document.addEventHandler('click', handler);
};
/**
* Test Code
*/
var _ = spies.Spies;
var _M = spies.Matcher;
var isAFunction = _M.isA(Function);
_.spy(object, 'fn');
_.spy(document, 'addEventHandler');
f();
expect(_.callCountOf(document.addEventHandler)('click', isAFunction)).to.be.equal(1);
// Now call the handler.
isAFunction.matchingArgs[0]();
expect(_.callCountOf(object.fn)()).to.be.equal(1);For more list of Matchers, go to the Matchers page.
Spies also comes with a convenience library to create fake objects. Look at Fakes for more documentations.
Spies comes with a Chai-expect plugin. To use it, HTML import the main_chai_expect.html file.
/**
* Test Code
*/
var _ = spies.Spies;
_.spy(object, 'fn');
object.fn(1);
object.fn();
expect(object.fn).calledWith(1).at.least(1);
expect(object.fn).called().at.least(2);var _ = spies.Spies;
_.spy(object, 'fn');
object.fn(1);
object.fn();
expect(object.fn).calledWith(1).before(object.fn).calledWith();
expect(object.fn).called().before(object.fn).calledWith();