@monstermann/fn/dist/string/indexOfOrThrow.js

A utility library for TypeScript.

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

//#region src/string/indexOfOrThrow.ts
/**
* `indexOfOrThrow(target, source)`
*
* Returns the index of the first occurrence of `source` string in `target` string, or throws an error if not found.
*
* ```ts
* indexOfOrThrow("hello world", "world"); // 6
* indexOfOrThrow("hello world", "foo"); // throws FnError
* ```
*
* ```ts
* pipe("hello world", indexOfOrThrow("world")); // 6
* pipe("hello world", indexOfOrThrow("foo")); // throws FnError
* ```
*/
const indexOfOrThrow = dfdlT((a, b) => {
	const idx = a.indexOf(b);
	if (Number.isFinite(idx)) return idx;
	throw new FnError("String.indexOfOrThrow: Value not found.", [a, b]);
}, 2);

//#endregion
export { indexOfOrThrow };