javascript - Cannot assign to read only property 'name' of object '[object Object]'

Question

The following code will throw an error only for the name property. It could be fixed by specifying name property as writable in Object.create arguments but I'm trying to understand why is this happening(and maybe there is a more elegant way to fix it).

var BaseClass = function (data) {
  Object.assign(this, data);
}

var ExtendedClass = function () {
  BaseClass.apply(this, arguments);
}

ExtendedClass.prototype = Object.create(BaseClass);

console.log(new ExtendedClass({ type: 'foo' }));
new ExtendedClass({ name: 'foo' });

Answer 1

If you get this error in Angular+Typescript+NgRX:

You can use the spread operator to take a shallow copy of a readonly object to make it readable, however you may not want this depending on your situation.

let x = [...y];

If you're using Redux / NgRX, there's a chance your selector could be returning a readonly object with a reference to the store, which can throw exceptions when trying to alter that object property via template binding. Depending on your situation, you can take a deep copy to remove the store reference.

let x = JSON.parse(JSON.stringify(y));