test

Bluff tests

Type the following command to run tests.

$ npm test

Overview

A promise represents the eventual result of an asynchronous operation. The primary way of interacting with a promise is through its then method, which registers callbacks to receive either a promise's eventual value or the reason why the promise cannot be fulfilled.

Our tests details the behavior of the then method, providing an interoperable base which all Promises/A+ conformant promise implementations can be depended on to provide.

The then Method

A promise must provide a then method to access its current or eventual value or reason.

A promise's then method accepts two arguments:

promise.then(onFulfilled, onRejected)

1. Both onFulfilled and onRejected are optional arguments:

   1. If onFulfilled is not a function, it must be ignored.
   2. If onRejected is not a function, it must be ignored.

2. If onFulfilled is a function:

   1. it must be called after promise is fulfilled, with promise's value as its first argument.
   2. it must not be called before promise is fulfilled.
   3. it must not be called more than once.

3. If onRejected is a function,

   1. it must be called after promise is rejected, with promise's reason as its first argument.
   2. it must not be called before promise is rejected.
   3. it must not be called more than once.

4. onFulfilled or onRejected must not be called until the execution context stack contains only platform code. [3.1].

5. onFulfilled and onRejected must be called as functions (i.e. with no this value). [3.2]

6. then may be called multiple times on the same promise.

   1. If/when promise is fulfilled, all respective onFulfilled callbacks must execute in the order of their originating calls to then.
   2. If/when promise is rejected, all respective onRejected callbacks must execute in the order of their originating calls to then.

7. then must return a promise [3.3].

   1. If either onFulfilled or onRejected returns a value x, run the Promise Resolution Procedure [[Resolve]](promise2, x).
   2. If either onFulfilled or onRejected throws an exception e, promise2 must be rejected with e as the reason.
   3. If onFulfilled is not a function and promise1 is fulfilled, promise2 must be fulfilled with the same value as promise1.
   4. If onRejected is not a function and promise1 is rejected, promise2 must be rejected with the same reason as promise1.