Deprecation Guide for Calling A as a constructor

The A function imported from @ember/array is a function that can be used to apply array mixins to an existing object (generally a native array):

import { A } from '@ember/array';

let arr = [];

A(arr);

arr.pushObject(1);

A will also return the "wrapped" array for convenience, and if no array is passed will create the array instead:

let arr1 = A([]);
let arr2 = A();

Because A is a standard function, it can also be used as a constructor. The constructor does not actually do anything different (because Javascript constructors can return something other than an instance). This was not intended behavior - A was originally implemented as an arrow function which cannot be used as a constructor, but as a side effect of transpilation it was turned into a normal function which could.

To update, remove any usage of new with A, and call A as a standard function. Before:

let arr = new A();

After:

let arr = A();

If linting rules prevent you from doing this, rename A to indicate that it is a function and not a constructor:

import { A as emberA } from '@ember/array';

let arr = emberA();