sw1tchdev/make-cancel-promise

Make your promises cancelable

make-cancel-promise

Make your promises cancelable

Install

NPM:

npm install make-cancel-promise

Features

1. Working with native, polyfills, shim'ed Promises
2. Isomorphic library
3. Zero dependencies
4. Typescript declarations

Usage example

Basic usage

import {
    makeCancelPromise, 
    CancelablePromiseError,
    cancelPromise
} from 'make-cancel-promise';

const cancelablePromise = makeCancelPromise(
    (resolve, reject, onCancel) => {
        const timeoutResolve = setTimeout(() => {
            resolve('resolve');
        }, 10);
        const timeoutReject = setTimeout(() => {
            reject('reject');
        }, 20);
        onCancel(() => {
            clearTimeout(timeoutResolve);
            clearTimeout(timeoutReject);
        });
});

cancelablePromise.catch((e) => {
    if(e instanceof CancelablePromiseError){
        console.log('Promise has been canceled');
    }       
});

cancelPromise(cancelablePromise).catch((e) => {
  console.error(e);
});

Cancel with ClearSymbol

import {
    makeCancelPromise, 
    CancelablePromiseError, 
    clearSymbol
} from 'make-cancel-promise';

const cancelablePromise = makeCancelPromise(
    (resolve, reject, onCancel) => {
        const timeoutResolve = setTimeout(() => {
            resolve('resolve');
        }, 10);
        const timeoutReject = setTimeout(() => {
            reject('reject');
        }, 20);
        onCancel(async () => {
            clearTimeout(timeoutResolve);
            clearTimeout(timeoutReject);
            });
});

cancelablePromise.catch((e) => {
    if(e instanceof CancelablePromiseError){
        console.log('Promise has been canceled');
    }       
});

cancelablePromise[clearSymbol]().catch((e) => {
  console.error(e);
});

Cancel with ClearSymbol without rejecting (using in some of cases)
Warning: You must resolve or reject promise in onCancel callback manually to prevent a pending promises in memory

import {
    makeCancelPromise, 
    CancelablePromiseError, 
    clearSymbol
} from 'make-cancel-promise';

const cancelablePromise = makeCancelPromise(
    (resolve, reject, onCancel) => {
        const timeoutResolve = setTimeout(() => {
            resolve('resolve');
        }, 10);
        const timeoutReject = setTimeout(() => {
            reject('reject');
        }, 20);
        onCancel(async () => {
            clearTimeout(timeoutResolve);
            clearTimeout(timeoutReject);
            
            // or resolve
            reject(new CancelablePromiseError('Error'));
        });
});

cancelablePromise.catch((e) => {
    if(e instanceof CancelablePromiseError){
        console.log('Promise has been canceled');
    }       
});

// passing false to "clearSymbol" function will be cancel promise without rejecting
cancelablePromise[clearSymbol](false).catch((e) => {
  console.error(e);
});