Promise Challenge

Story

• The client comes from a religious background and isn't comfortable with the word "promise" being part of their software
• The client wants a new class to replace the Promise, called... Declare
• clone this Repo.
• run npm i to install jest test library in order for the tests to run.
• Edit index.js to implement the Declare class.
• run npm run test in the terminal to run the tests.

Requirements from the Declare class

1. is not implemented using the built-in Promise Class.
2. can create an instance with an executor function using the new keyword
3. has a then method, which returns a Declare instance
4. can use the return value of the executor with then method
5. can use multiple thens chained one after the other
6. can use an asynchronous executor

• NOTE - there's no need to handle errors in this implementation.

HOT TIP

add .skip to the end of a test in test.js to skip it in a run, and only test what you want to.

test.skip("Is not an instance of Promise", () => {
    const declare = new Declare(()=>{});
    return expect(declare instanceof Promise).toBe(false);
  });

Recommended prior Knowledge

try to pass this challange using only the resources below: (don't look for other implementations)

• How Promise works? Promise MDN Promises - why!? Callback-Hell VS Promises

• JS classes + constructor: class guide class MDN

• JS, how does it reads your code? Asynchrony: Under the Hood

• bind is a method in js, which pssing a 'this' value, to another function. it is necessary to use this method in the implementation.
  (learn more here)[https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/bind]

HINTS

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