renameKeys

1/**
2 * Renames keys of an object based on a mapping.
3 * Keys not present in the mapping are preserved as-is.
4 *
5 * @param obj - The original object.
6 * @param keyMap - An object defining the old-to-new key mapping.
7 * @returns A new object with renamed keys.
8 */
9export function renameKeys(
10  obj: Record<string, any>,
11  keyMap: Record<string, string>
12): Record<string, any> {
13  return Object.fromEntries(
14    Object.entries(obj).map(([key, value]) => [keyMap[key] ?? key, value])
15  );
16}

1test('renameKeys - renames matching keys', () => {
2  const obj = { a: 1, b: 2, c: 3 };
3  const map = { a: 'x', b: 'y' };
4  expect(renameKeys(obj, map)).toEqual({ x: 1, y: 2, c: 3 });
5});
6
7test('renameKeys - empty key map returns original keys', () => {
8  const obj = { foo: 42 };
9  expect(renameKeys(obj, {})).toEqual({ foo: 42 });
10});
11
12test('renameKeys - empty object returns empty object', () => {
13  const map = { a: 'x' };
14  expect(renameKeys({}, map)).toEqual({});
15});
16
17test('renameKeys - key not in map stays the same', () => {
18  const obj = { hello: 'world' };
19  const map = { foo: 'bar' };
20  expect(renameKeys(obj, map)).toEqual({ hello: 'world' });
21});
22
23test('renameKeys - works with nested keys (flat only)', () => {
24  const obj = { a: 1, 'b.c': 2 };
25  const map = { 'b.c': 'd.e' };
26  expect(renameKeys(obj, map)).toEqual({ a: 1, 'd.e': 2 });
27});