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

A utility library for TypeScript.

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

//#region src/array/lastIndexOfOrThrow.ts
/**
* `lastIndexOfOrThrow(target, value)`
*
* Returns the index of the last occurrence of `value` in `target`. If `value` is not found, throws an error.
*
* ```ts
* lastIndexOfOrThrow([1, 2, 3, 2], 2); // 3
* lastIndexOfOrThrow([1, 2, 3], 4); // throws FnError
* ```
*
* ```ts
* pipe([1, 2, 3, 2], lastIndexOfOrThrow(2)); // 3
* pipe([1, 2, 3], lastIndexOfOrThrow(4)); // throws FnError
* ```
*/
const lastIndexOfOrThrow = dfdlT((target, value) => {
	const idx = target.lastIndexOf(value);
	if (idx < 0) throw new FnError("Array.lastIndexOf: No value found.", [target, value]);
	return idx;
}, 2);

//#endregion
export { lastIndexOfOrThrow };