@sweet-monads/async

@sweet-monads/async

Package for better developer experience with Promise and @sweet-monad/interfaces/Monad

This library belongs to sweet-monads project

sweet-monads — easy-to-use monads implementation with static types definition and separated packages.

• No dependencies, one small file
• Easily auditable TypeScript/JS code
• Check out all libraries: maybe, iterator, interfaces,

Usage

npm install @sweet-monads/async

import { chain } from "@sweet-monads/async";
import { right } from "@sweet-monads/either";

const fn = () =>
  Promise.resolve(right("Hello, Sweet Monad."))
    .then(chain(doSomethingAsync))
    .then(chain(doOneMoreAsyncThing));

API

• chain

chain

  chain<T, R>(fn: (v: T) => Promise<Monad<R>>): (m: Monad<T>) => Promise<Monad<R>>;

• f: (v: T) => Promise<Monad<R>> - async function which convert a Monad to another one.
• Returns Promise with mapped by fn function value wrapped by Monad by the Monad implementation rule.

Example:

declare function getUser(email: string): Promise<Either<UserNotFoundError, User>>;
declare function arePasswordsMatched(password: string, user: User): Promise<Either<WrongCredentialsError, boolean>>;

// result is Promise<Either<UserNotFoundError | WrongCredentialsError, boolean>>
const result = getUser("[e-mail]")
  .then(chain(user => arePasswordsMatched("some password", user.password)));

License

MIT (c) Artem Kobzar see LICENSE file.