@naturalcycles/js-lib/dist/promise/pState.js

Standard library for universal (browser + Node.js) javascript

const UNIQUE_VALUE = Symbol('unique');
/**
 * Returns the state of the Promise, one of:
 * - pending
 * - resolved
 * - rejected
 *
 * Based on: https://makandracards.com/makandra/46681-javascript-how-to-query-the-state-of-a-native-promise
 */
export async function pState(p) {
    return await Promise.race([p, Promise.resolve(UNIQUE_VALUE)]).then(v => {
        return v === UNIQUE_VALUE ? 'pending' : 'resolved';
    }, () => 'rejected');
}