// @flow /* eslint-disable es5/no-es6-methods */ /* eslint-disable es5/no-es6-static-methods */ /* eslint-disable no-restricted-globals */ type Map = { [key: string]: T, }; export function isInteger(value: mixed): boolean { if (Number.isInteger) { return Number.isInteger(value); } return ( typeof value === 'number' && isFinite(value) && Math.floor(value) === value ); } // Using this helper to ensure there are correct flow types // https://github.com/facebook/flow/issues/2221 export function values(map: Map): T[] { if (Object.values) { // $FlowFixMe - Object.values currently does not have good flow support return Object.values(map); } return Object.keys(map).map(key => map[key]); } // Could also extend to pass index and list type PredicateFn = (value: T) => boolean; // TODO: swap order export function findIndex( list: Array, predicate: PredicateFn, ): number { if (list.findIndex) { return list.findIndex(predicate); } // Using a for loop so that we can exit early for (let i = 0; i < list.length; i++) { if (predicate(list[i])) { return i; } } // Array.prototype.find returns -1 when nothing is found return -1; } export function find(list: Array, predicate: PredicateFn): ?T { if (list.find) { return list.find(predicate); } const index: number = findIndex(list, predicate); if (index !== -1) { return list[index]; } // Array.prototype.find returns undefined when nothing is found return undefined; } // Using this rather than Array.from as Array.from adds 2kb to the gzip // document.querySelector actually returns Element[], but flow thinks it is HTMLElement[] // So we downcast the result to Element[] export function toArray(list: NodeList): Element[] { return Array.prototype.slice.call(list); }