@monstermann/fn/dist/array/replaceLastOrThrow.js

A utility library for TypeScript.

import { FnError } from "../function/FnError.js";
import { is } from "../function/is.js";
import { dfdlT } from "@monstermann/dfdl";
import { cloneArray } from "@monstermann/remmi";

//#region src/array/replaceLastOrThrow.ts
/**
* `replaceLastOrThrow(target, value, replacement)`
*
* Replaces the last occurrence of `value` in `target` with `replacement`. If `value` is not found, throws an error.
*
* ```ts
* replaceLastOrThrow([1, 2, 3, 2], 2, 9); // [1, 2, 3, 9]
* replaceLastOrThrow([1, 2, 3], 4, 9); // throws FnError
* ```
*
* ```ts
* pipe([1, 2, 3, 2], replaceLastOrThrow(2, 9)); // [1, 2, 3, 9]
* pipe([1, 2, 3], replaceLastOrThrow(4, 9)); // throws FnError
* ```
*/
const replaceLastOrThrow = dfdlT((target, value, replacement) => {
	if (is(value, replacement)) return target;
	const idx = target.lastIndexOf(value);
	if (idx === -1) throw new FnError("Array.replaceLastOrThrow: Value not found", [
		target,
		value,
		replacement
	]);
	const result = cloneArray(target);
	result.splice(idx, 1, replacement);
	return result;
}, 3);

//#endregion
export { replaceLastOrThrow };