vanilla-type-check/isPlainObject.js

Basic type checker

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
// same implementation as lodash library
var objectProto = Object.prototype;
var hasOwnProperty = objectProto.hasOwnProperty;
var toString = objectProto.toString;
var symToStringTag = typeof Symbol != 'undefined' ? Symbol.toStringTag : undefined;
/*
 * lodash.baseGetTag
 */
/* istanbul ignore next */
function baseGetTag(value) {
    if (value == null) {
        return value === undefined ? '[object Undefined]' : '[object Null]';
    }
    if (!(symToStringTag && symToStringTag in Object(value))) {
        return toString.call(value);
    }
    var isOwn = hasOwnProperty.call(value, symToStringTag);
    var tag = value[symToStringTag];
    var unmasked = false;
    try {
        value[symToStringTag] = undefined;
        unmasked = true;
    }
    catch (e) { }
    var result = toString.call(value);
    if (unmasked) {
        if (isOwn) {
            value[symToStringTag] = tag;
        }
        else {
            delete value[symToStringTag];
        }
    }
    return result;
}
/*
 * lodash.isObjectLike
 */
/* istanbul ignore next */
function isObjectLike(value) {
    return typeof value == 'object' && value !== null;
}
/**
 * Check if a value is a plain object (that is, not a class instance, etc.)
 *
 * @param value value to check
 * @returns `true` if `obj` is a plain object
 */
function isPlainObject(value) {
    if (!isObjectLike(value) || baseGetTag(value) != '[object Object]') {
        return false;
    }
    if (Object.getPrototypeOf(value) === null) {
        return true;
    }
    var proto = value;
    while (Object.getPrototypeOf(proto) !== null) {
        proto = Object.getPrototypeOf(proto);
    }
    return Object.getPrototypeOf(value) === proto;
}
exports.isPlainObject = isPlainObject;