var ctx = {
                            stripe: {customers: {
                                createSource: R.always(BPromise.resolve())
                            }},
                            user: {stripeCustomer: {}}
                        };
                        return addCard.call(ctx).should.be.Promise;

var ctx = {
                            stripe: {customers: {
                                createSource: R.always(BPromise.resolve({}))
                            }},
                            user: {stripeCustomer: {}}
                        };
                        return addCard.call(ctx).should.be.fulfilledWith({});

var ctx = {
                            stripe: {customers: {
                                createSource: function () {
                                    return BPromise.reject();
                                }
                            }},
                            user: {stripeCustomer: {}}
                        };
                        return addCard.call(ctx).should.be.rejectedWith("Error while adding the card.");

var ctx = {
                            stripe: {customers: {
                                deleteCard: R.always(BPromise.resolve())
                            }},
                            user: {stripeCustomer: {}}
                        };
                        return deleteCard.call(ctx).should.be.Promise;

var ctx = {
                            stripe: {customers: {
                                deleteCard: R.always(BPromise.resolve({}))
                            }},
                            user: {stripeCustomer: {}}
                        };
                        return deleteCard.call(ctx).should.be.fulfilledWith({});

var ctx = {
                            stripe: {customers: {
                                deleteCard: function () {
                                    return BPromise.reject();
                                }
                            }},
                            user: {stripeCustomer: {}}
                        };
                        return deleteCard.call(ctx).should.be.rejectedWith("Error while deleting the card.");

var ctx = {
                            userId: null
                        };
                        return ensureLogin.bind(ctx).should.throw("Login required.");

var ctx = {
                            userId: "someId"
                        };
                        return ensureLogin.bind(ctx).should.not.throw();

var ctx = {
                            stripe: {customers: {
                                retrieve: R.always(BPromise.resolve())
                            }},
                            db: {collection: R.always({
                                update: function (first, second, cb) {
                                    cb(false, {});
                                }
                            })},
                            user: {stripeCustomer: {}}
                        };
                        return stripeCustomerSync.call(ctx).should.be.Promise;