Typescript error runtime error: Cannot read property 'prototype' of undefined when extending

Question

So I\'m getting the above error in the console. It\'s caused by _super being undefined when it\'s passed to __extends (in the generated .js

Answer 1

The order of the scripts on your HTML matters.

Say you have a TypeScript file A.ts that defines an abstract class and a file B.ts with a class that extends the abstract class in A.ts

export abstract class ShipmentsListScope implements IShipmentsListScope {

A.ts:

module app.example{
  "use strict";

  interface IMyInterface{
    // ..
  } 
  export abstract class MyAbstract implements IMyInterface{
    // ..
  }
}

B.ts

module app.example{
    "use strict";

  class MyChildClass extends MyAbstract {
    // ...
  }
}

then in your HTML you have to ensure that the order of the scripts is correct once the javascripts have been generated: