ts_temp/is/plainObject.js

import isReactElement from './reactElement';
import isReactComponent from './reactComponent';
import isObject from './object';
/**
 * Returns whether a value is a plain object
 * (an object that is created using an object literal, Object.create(null) or similar).
 * Rejects anything with a custom prototype or a non-object ECMAScript type.
 * Also rejects React elements and components
 *
 * **Note:** if the host environment does not support Symbol, any object with a $$typeof
 * property is considered a React element
 *
 * @param {*} test The value to check
 * @returns {boolean} Returns `true` if `test` is a plain object, else `false`.
 * @example
 *
 * isPlainObject({ a: 'test' }); // => true
 *
 * isPlainObject(moment()); // => false
 *
 * isPlainObject(<span></span>); // => false
 */
export default function isPlainObject(test) {
    if (!isObject(test)) {
        return false;
    }
    const prototype = Object.getPrototypeOf(test);
    if (prototype === null) {
        // objects created with Object.create(null) are still plain objects
        return true;
    }
    if (prototype !== Object.prototype) {
        // has a custom prototype, probably was created with a custom constructor,
        // may contain internal data that's not meant to be accessed from outside
        return false;
    }
    if (isReactElement(test) || isReactComponent(test)) {
        // react elements _are_ plain objects, but we don't treat them like that
        // (e.g. in recursive merges)
        return false;
    }
    return true;
}