Node.js V6.2.0 Class Extends Is Not A Function Error? July 18, 2022 Post a Comment So I'm trying to extend a class in node js and the compiler keeps returning the following error: TypeError: Class extends value # is not a function or null I checked Solution 1: So it turns out I had a circular reference in my code, where I was importing the class that was extending, into the class that itself was extending (tongue twister :P). The obvious fix was to simply remove the extends reference and find another way of doing what I was trying to achieve. In my case it was passing the Venue class properties down into the VenueViews constructor. E.g var x = VenueViews(this) Solution 2: In my instance, it was the same issue as @James111 was experiencing (circular import) due to a factory pattern I was trying to set up in Typescript. My fix was to do move the code into files, similar to the following:Baca JugaReading / Assigning Reference Types In JavascriptWhy Doesn't Array#map Return The Correct Array?React And Es6 Inheritance // ./src/interface.ts import { ConcreteClass } from './concrete'; export interface BaseInterface { someFunction(): any; } export class Factory { static build(): BaseInterface { return new ConcreteClass(); } } // ./src/base.ts import { BaseInterface } from './interface'; class BaseClass implements BaseInterface { someFunction(): any { return true; } } // ./src/concrete.ts import { BaseClass } from './base'; export class ConcreteClass extends BaseClass { someFunction(): any { return false; } } Copy Solution 3: I had faced similar issue, after checking all the workaround finally issue got resolved by deleting the node_modules folder and run npm i. Share You may like these postsHow To Declare Private Variables And Private Methods In Es6 ClassReact 0.13 Class Method UndefinedWebpack - Loading Chunk 0 FailedHow To Toggle On Order In Reactjs Post a Comment for "Node.js V6.2.0 Class Extends Is Not A Function Error?"