Sinon Chai assertions in expect style.Examples from http://chaijs.com/plugins/sinon-chai #sinon #chai #javascript

sinon-chai-expect.md

Sinon JS

##Spies

//Anonymous function
var spy = sinon.spy();

//Provided Function
var spy = sinon.spy(myFunc);

//Existing object and function
var spy = sinon.spy(object, "method");

//Pass the spy as a function
PubSub.subscribe("message", spy);

Example -Spying on existing methods

//Spy on existing function
sinon.spy(jQuery, "ajax");

//Use function
jQuery.getJSON("/some/resource");

//Assert
expect(jQuery.ajax).to.have.been.called;

//Restore afterwards
jQuery.ajax.restore();

Stubs

Test stubs are functions (spies) with pre-programmed behavior.

Create Stubs

//Anonymous stub
var stub = sinon.stub();

//Replaces object.method with a stub function
var stub = sinon.stub(object, "method", func);
//Restore original method
stub.restore();

//Stub a whole object
var stub = sinon.stub(obj);

Instead of

sinon.assertCalledWith(mySpy, "foo");

call

expect(mySpy).to.have.been.calledWith("foo");

Sinon Syntax	Sinon-Chai Assertion
called	expect(spy).to.have.been.called
calledOnce	expect(spy).to.have.been.calledOnce
calledTwice	expect(spy).to.have.been.calledTwice
calledThrice	expect(spy).to.have.been.calledThrice
calledBefore	expect(spy1).to.have.been.calledBefore(spy2)
calledAfter	expect(spy1).have.been.calledAfter(spy2)
calledWithNew	expect(spy).to.have.been.calledWithNew
alwaysCalledWithNew	expect(spy).to.always.have.been.calledWithNew
calledOn	expect(spy).to.have.been.calledOn(context)
alwaysCalledOn	expect(spy).to.always.have.been.calledOn(context)
calledWith	expect(spy).to.have.been.calledWith(...args)
alwaysCalledWith	expect(spy).to.always.have.been.calledWith(...args)
calledWithExactly	expect(spy).to.have.been.calledWithExactly(...args)
alwaysCalledWithExactly	expect(spy).to.always.have.been.calledWithExactly(...args)
calledWithMatch	expect(spy).to.have.been.calledWithMatch(...args)
alwaysCalledWithMatch	expect(spy).to.always.have.been.calledWithMatch(...args)
returned	expect(spy).to.have.returned(returnVal)
alwaysReturned	expect(spy).to.have.always.returned(returnVal)
threw	expect(spy).to.have.thrown(errorObjOrErrorTypeStringOrNothing)
alwaysThrew	expect(spy).to.have.always.thrown(errorObjOrErrorTypeStringOrNothing)