@monstermann/fn/dist/object/map.js

A utility library for TypeScript.

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

//#region src/object/map.ts
/**
* `map(target, key, transform)`
*
* Creates a new object with the `key` property transformed by the `transform` function.
*
* ```ts
* map({ a: 1, b: 2 }, "a", (x) => x * 2); // { a: 2, b: 2 }
* ```
*
* ```ts
* pipe(
*     { a: 1, b: 2 },
*     map("a", (x) => x * 2),
* ); // { a: 2, b: 2 }
* ```
*/
const map = dfdlT((target, key, transform) => {
	const prev = target[key];
	const next = transform(prev);
	if (is(prev, next)) return target;
	const result = cloneObject(target);
	result[key] = next;
	return result;
}, 3);

//#endregion
export { map };