percentOf

1/**
2 * Calculates the numeric value representing a percentage of a total.
3 *
4 * @param total - The total value.
5 * @param percent - The percentage to calculate (e.g. 17 for 17%).
6 * @returns The value corresponding to the given percent of the total.
7 */
8export function percentOf(total: number, percent: number): number {
9  return (total * percent) / 100;
10}

1test('percentOf - typical percentage', () => {
2  expect(percentOf(200, 25)).toBe(50);
3});
4
5test('percentOf - zero percent', () => {
6  expect(percentOf(142, 0)).toBe(0);
7});
8
9test('percentOf - full percent (100%)', () => {
10  expect(percentOf(142, 100)).toBe(142);
11});
12
13test('percentOf - decimal percent', () => {
14  expect(percentOf(142, 17.5)).toBeCloseTo(24.85);
15});
16
17test('percentOf - over 100 percent', () => {
18  expect(percentOf(80, 150)).toBe(120);
19});
20
21test('percentOf - negative percent', () => {
22  expect(percentOf(200, -10)).toBe(-20);
23});
24
25test('percentOf - negative total', () => {
26  expect(percentOf(-100, 25)).toBe(-25);
27});