// Loaded from https://deno.land/x/graphql_deno@v15.0.0/lib/jsutils/isCollection.js import { SYMBOL_ITERATOR } from '../polyfills/symbols.js'; /** * Returns true if the provided object is an Object (i.e. not a string literal) * and is either Iterable or Array-like. * * This may be used in place of [Array.isArray()][isArray] to determine if an * object should be iterated-over. It always excludes string literals and * includes Arrays (regardless of if it is Iterable). It also includes other * Array-like objects such as NodeList, TypedArray, and Buffer. * * @example * * isCollection([ 1, 2, 3 ]) // true * isCollection('ABC') // false * isCollection({ length: 1, 0: 'Alpha' }) // true * isCollection({ key: 'value' }) // false * isCollection(new Map()) // true * * @param obj * An Object value which might implement the Iterable or Array-like protocols. * @return {boolean} true if Iterable or Array-like Object. */ export default function isCollection(obj) { if (obj == null || typeof obj !== 'object') { return false; } // Is Array like? const length = obj.length; if (typeof length === 'number' && length >= 0 && length % 1 === 0) { return true; } // Is Iterable? return typeof obj[SYMBOL_ITERATOR] === 'function'; }