1369793 - Confusing error when |class C extends null|

Status: NEW

(Core :: JavaScript Engine, defect, P3)

Description

[Ted Campbell [:tcampbell]]

Silly example:
> var B = null;
> class C extends B {
>   a() { return super.x; }
> }
> new C()

FF gives the following error message.
> TypeError: function () { } is not a constructor
This is confusing because an empty function is a constructor and the problem is related to super constructor instead.

As an example, chrome correctly explains:
> Uncaught TypeError: Super constructor null of C is not a constructor
>    at C (<anonymous>:1:1)
>    at <anonymous>:1:1