Do not access Object.prototype method 'hasOwnProperty' from target object.
1213 let f = ''
1214
1215 for (const k in window) {
1216 if (window.hasOwnProperty(k)) {1217 if (String(k).substr(0, 2) === 'nu') {
1218 f += k + '\n'
1219 }Do not access Object.prototype method 'hasOwnProperty' from target object.
1243 if (typeof obj === 'object') {
1244 str = '{'
1245 for (const i in obj) {
1246 if (obj.hasOwnProperty(i)) {1247 str += (first ? '' : ', ') + i + ':' + util.stringify(obj[i])
1248 first = false
1249 }Do not access Object.prototype method 'hasOwnProperty' from target object.
1070 }
1071
1072 for (const property in source) {
1073 if (source.hasOwnProperty(property)) {1074 const sourceProperty = source[property]
1075
1076 if (typeof sourceProperty === 'object') {Do not access Object.prototype method 'hasOwnProperty' from target object.
942 applyCSS: function (el, styles) {
943 /* Applies CSS to a single element */
944 for (const prop in styles) {
945 if (styles.hasOwnProperty(prop)) { 946 el.style[prop] = styles[prop]
947 }
948 }Do not access Object.prototype method 'hasOwnProperty' from target object.
931 delete attrs.style
932 }
933 for (attr in attrs) {
934 if (attrs.hasOwnProperty(attr)) { 935 el[attr] = attrs[attr]
936 }
937 }
Description
It is preferable to call certain Object.prototype methods through Object on object instances instead of using the builtins directly.
Objects can have properties that shadow the builtins on Object.prototype, potentially causing unintended behavior or denial-of-service security vulnerabilities.
For example, it would be unsafe for a webserver to parse JSON input from a client and call hasOwnProperty directly on the resulting object, because a malicious client could send a JSON value like {"hasOwnProperty": 1} and cause the server to crash.
It's better to always call these methods from Object.prototype. For example, obj.hasOwnProperty("bar") should be replaced with Object.prototype.hasOwnProperty.call(obj, "bar").
Bad Practice
let hasBarProperty = obj.hasOwnProperty("property");
let isPrototypeOfBar = obj.isPrototypeOf(property);
let barIsEnumerable = obj.propertyIsEnumerable("property");
Recommended
let hasBarProperty = Object.prototype.hasOwnProperty.call(obj, "property");
let isPrototypeOfBar = Object.prototype.isPrototypeOf.call(obj, property);
let barIsEnumerable = {}.propertyIsEnumerable.call(obj, "property");