Unopinionated promise mocking

PromiseMock.spec.js

describe('An object which relies on promises', function () {
    it('Should pass if provided the proper parameters', function () {
        /**
          * our real object would normally depend on promiseDependency,
          * but we're replacing it with our mock promise chain here.
        */
        sut.promiseDependency = PromiseMocks.ResolveMock();

        var params = {
            name : 'alex'
        };

        sut.doLongRunningWork(params);
        expect(params.name).to.equal('alex changed');

    });
});


describe('An object which relies on promises', function () {
    it('Should pass if provided the proper parameters', function () {

        sut.promiseDependency = PromiseMocks.RejectMock();
        var params = {
            name : 'alex'
        };

        expect(function(){
            sut.doLongRunningWork(params);
        }).to.throw();
    });
});

PromiseMocks.js

"use strict";
module.exports = {
    //creates a function which returns a fake promise that always resolves
    ResolveMock: function () {
	
        return function(params){
            var promise = {
                then : function (cb) {
                    cb(params);
                    return this;
                },
                catch: function (cb) {
                    //dont call the cb
                    return this;
                },
                done : function (cb) {
                    cb();
                }
            };
            return promise;
        };

    },
    //creates a function which returns a fake promise that always rejects
    RejectMock : function () {
        return function(error){
            var promise = {
                then : function (cb) {
                    return this;
                },
                catch: function (cb) {
                    cb(error);
                    return this;
                },
                done : function (cb) {
                    cb();
                }
            };
            return promise;
        };
    }
};