util.inherits does not establish prototype chain #4179
Description
In inherits.js Object.setPrototypeOf is being called with the wrong parameters.
The reason for me assuming that the wrong parameters are being used is
(REPL)
> function MyError() {} > util.inherits(MyError, Error); > MyError { [Function: MyError] super_: { [Function: Error] captureStackTrace: [Function: captureStackTrace], stackTraceLimit: 10 } } > Error.isPrototypeOf(MyError); false While inheritance sort of works, the prototype chain is actually never established.
> myerr = new MyError() [Error] > myerr instanceof MyError true > myerr instanceof Error true Replacing the existing call to Object.setPrototypeOf() by
Object.setPrototypeOf(ctor, superCtor); See https://github.com/nodejs/node/blob/master/lib/util.js#L805.
(REPL)
> function MyError() {} > util.inherits(MyError, Error); > MyError [Function: OError] > Error.isPrototypeOf(MyError); true Yet, instanceof will now fail
> myerr = new MyError() [Error] > myerr instanceof MyError true > myerr instanceof Error false When using the new class feature, everything works as expected, though
(REPL)
> class MyError extends Error {} [Function: MyError] > Error.isPrototypeOf(MyError) true > myerr = new MyError() [Error] > myerr instanceof MyError true > myerr instanceof Error true