How to export a prototype method?
I created a prototype method:
Array.prototype.remove = function(elementToRemove: any): void {
var __idx = this.indexOf(elementToRemove);
if (__idx >= 0) {
this.splice(__idx, 1);
} else {
throw new Error(`Cannot find element ${elementToRemove}`)
}
}
and I want to export it and use in another file. But I don't know how to add export to it:
both
export Array.prototype.remove = function(elementToRemove: any)
and
Array.prototype.remove = export function(elementToRemove: any)
doesn't work, I received 'Expression expected' Error. So how can I export it?
ps: I'm not using nodejs, I'm using web frontend in chrome with HTML and CSS.
The fundamental issue is that your code performs a side-effect - it adds something to Array.prototype.
One option is to export a function that, when called, adds the function to the prototype:
export const addRemoveToPrototype = () => {
Array.prototype.remove = function( // ...
and then consumers can use it by doing
import { addRemoveToPrototype } from './addRemoveToPrototype';
addRemoveToPrototype();
Another option is to simply run that code at the top level of the module:
Array.prototype.remove = function(elementToRemove: any): void {
and then consumers can just import the module, but not do anything with it:
import './addRemoveToPrototype';
That said, I'd really recommend not mutating built-in objects - it makes the code fragile and more easily breakable, especially when other scripts run in the same environment.