diff options
Diffstat (limited to 'js/util.ts')
-rw-r--r-- | js/util.ts | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/js/util.ts b/js/util.ts index e6f38c8e1..b81b96aca 100644 --- a/js/util.ts +++ b/js/util.ts @@ -142,3 +142,33 @@ export function getPrivateValue< } throw new TypeError("Illegal invocation"); } + +/** + * Determines whether an object has a property with the specified name. + * Avoid calling prototype builtin `hasOwnProperty` for two reasons: + * + * 1. `hasOwnProperty` is defined on the object as something else: + * + * const options = { + * ending: 'utf8', + * hasOwnProperty: 'foo' + * }; + * options.hasOwnProperty('ending') // throws a TypeError + * + * 2. The object doesn't inherit from `Object.prototype`: + * + * const options = Object.create(null); + * options.ending = 'utf8'; + * options.hasOwnProperty('ending'); // throws a TypeError + * + * @param obj A Object. + * @param v A property name. + * @see https://eslint.org/docs/rules/no-prototype-builtins + * @internal + */ +export function hasOwnProperty<T>(obj: T, v: PropertyKey): boolean { + if (obj == null) { + return false; + } + return Object.prototype.hasOwnProperty.call(obj, v); +} |