Cannot instantiate class directly from module.__get__

[justinlovinger]

Description

TypeError: Class constructor … cannot be invoked without 'new' is thrown when attempting to instantiate a class directly from module.__get__. However, if the class is first bound to a local variable, such as MyClass = module.__get__('MyClass'), the class can be instantiated.

Reproduction

hasclass.js

class Foo {

}

dorewire.js

const rewire = require('rewire');
const hasclass = rewire('./hasclass.js');

// No error when class if first bound to a local variable
const Foo = hasclass.__get__('Foo');
const foo1 = new Foo();

// Throws error if class is not bound to a local variable
const foo2 = new hasclass.__get__('Foo')();

Context:

• Library version: 4.0.1
• Environment: Windows