Need tests, docs, and typings for Future

[tshemsedinov]

We have implementation moved from https://github.com/HowProgrammingWorks/Future but need tests, docs, and typings as well.

Refs: #260

[c-0d3-r]

@tshemsedinov Can I take task for adding typings?

[axbuglak]

I can also help with writing tests and documentation

[tshemsedinov]

Implementation: @c-0d3-r
Review: @axbuglak @tshemsedinov

[c-0d3-r]

type FutureExecutor = (resolve: Function, reject?: Function) => void;

interface Thenable<T = unknown> {
  then(resolve: Resolve<T>, reject: Reject): void;
}

export class Future {
  // #1
  constructor(executor: FutureExecutor);
  // #2
  constructor(executor: Function);
  static of(value: unknown): Future;
  chain(fn: Function): Future;
  map(fn: Function): Future;
  fork(successed: Function, failed?: Function): void;
  toPromise(): Promise<unknown>;
  toThenable(): Thenable<unknown>;
}

// #1
type CallbackLastParams = [...params: Array<unknown>, callback: Function];
export function futurify(fn: Function): (...args: CallbackLastParams) => Future;

// #2
export function futurify(fn: Function): (...args: Array<unknown>) => Future;

[c-0d3-r]

@tshemsedinov @axbuglak

with generics

type Resolve<T = unknown> = (value: T) => void;
type Reject = (reason?: Error | unknown) => void;
type Executor<T = unknown> = (resolve: Resolve<T>, reject?: Reject) => void;

interface Thenable<T = unknown> {
  then(resolve: Resolve<T>, reject: Reject): void;
}

export class Future<T = unknown> {
  static of<U = unknown>(value: U): Future<U>;
  constructor(executor: Executor<T>);
  chain<U = T>(fn: (value: T) => Future<U>): Future<U>;
  map<U = T>(fn: (value: T) => U): Future<U>;
  fork(successed: Resolve<T>, failed?: Reject): void;
  toPromise(): Promise<T>;
  toThenable(): Thenable<T>;
}

type CallbackLastParams = [...args: Array<unknown>, callback: Function];
type CallbackLastFn = (...args: CallbackLastParams) => unknown;

export function futurify(
  fn: CallbackLastFn,
): (...args: CallbackLastParams) => Future;

[axbuglak]

type FutureExecutor = (resolve: Function, reject?: Function) => void;

export class Future {
  // #1
  constructor(executor: FutureExecutor);
  // #2
  constructor(executor: Function);
  static of(value: unknown): Future;
  chain(fn: Function): Future;
  map(fn: Function): Future;
  fork(successed: Function, failed?: Function): void;
  toPromise(): Promise<unknown>;
  toThenable(): Promise<unknown>;
}

// #1
type CallbackLastParams = [...params: Array<unknown>, callback: Function];
export function futurify(fn: Function): (...args: CallbackLastParams) => Future;

// #2
export function futurify(fn: Function): (...args: Array<unknown>) => Future;

The first variant looks good, but can you please open a PR for it so i wil be able to edit something. For example toThenable method returns not just a Promise, but an object { then }

And would you like to write a documentation and tests too? Or may I take it?

[c-0d3-r]

@axbuglak Yes, I will open a PR and adjust typings for toThenable as well. As you mentioned you can take writing docs and tests - no problems

[tshemsedinov]

interface Thenable<T = unknown> {
  then(resolve: Resolve<T>, reject: Reject): unknown;
}

toCallbackLast(): CallbackLastFn;

3. Rename CallbackLastFn to CallbackLastFunction