Example: Chained Promises with Chai-as-Promised & Mocha

Scenario:

CheckoutActions.initCheckout()
 .then(() => {
   return CheckoutActions.getCheckoutConfirmation();
 });

Test:

return expect(CheckoutActions.initCheckout()).to.eventually.be.fulfilled
 .then(() => {
 expect(CheckoutActions.getCheckoutConfirmation).to.have.been.called;
 });