should-promised

Define some helpers for asserting promises.

.Promise()

Assert that the given object is an instance of a Promise

.fulfilled()

Assert that the given promise will be fulfilled. It will return a promise.

it('should be allowed to check if promise fulfilled', function() {
  return promised(10).should.be.fulfilled();
});

.fulfilledWith(value)

Assert that the given promise will be fulfilled with an expected value. It will return a promise.

it('should be allow to check if promise fulfilledWith an expected value', function() {
  return promised(10).should.be.fulfilledWith(10);
});

.rejected()

Assert that the given promise will be rejected. It will return a promise.

it('should be allow to check if promise rejected', function() {
  return promiseFail().should.be.rejected();
});

.rejectedWith(Error)

Assert that the given promise will be rejected with the matched Error. Arguments are the same as Assertion#throw.

.finally or .eventually

This method begin assertions for promises, all next .chain calls will be shortcuts for .thenable calls on promise.

So you can do something like this

promised('abc').should.finally.be.exactly('abc')
      .and.be.a.String();

//or combine with any of Promise methods as any assertion will return Promise itself

Promise.all([
  promised(10).should.finally.be.a.Number(),
  promised('abc').should.finally.be.a.String()
])

Before .finally

Everything you did before .finally is saved into a new assertion (but that is not quite as useful, as the object will be a promise). The main idea is to save .not and .any.