enhancedmath/lib/__tests__/combination.test.js

This package contains some enhanced mathematical operations

import { describe, test, expect } from 'vitest';
import combination from '../Probability/combination';
describe('Combination', () => {
    test('should return 1 for a 1C1', () => {
        const result = combination(1, 1);
        expect(result).toBe(1n);
    });
    test('should return 6 for a 4C2', () => {
        const result = combination(4, 2);
        expect(result).toBe(6n);
    });
    test('should return 1287 for a 13C5', () => {
        const result = combination(13, 5);
        expect(result).toBe(1287n);
    });
    test('should return 2.709909177e+58 for 200C89', () => {
        const result = combination(200, 89);
        expect(result).toBe(27099091778516175766475545995162244775768017861168866192000n);
    });
    test('should return undefined for fractional values', () => {
        // This test is purely for javascript users who can't read docs and still want to try and calculate a combination involving a fraction
        let result = combination(13 / 4, 5);
        expect(result).toBe(undefined);
        result = combination(13, 5 / 4);
        expect(result).toBe(undefined);
        result = combination(13 / 4, 5 / 4);
        expect(result).toBe(undefined);
    });
    test('should return undefined for non numerical values', () => {
        // This test is purely for javascript users who can't read docs and still want to try and calculate a combination involving a string
        //@ts-expect-error - Testing for non numerical values
        let result = combination('13', 5);
        expect(result).toBe(undefined);
        //@ts-expect-error - Testing for non numerical values
        result = combination(13, '5');
        expect(result).toBe(undefined);
        //@ts-expect-error - Testing for non numerical values
        result = combination('13', '5');
        expect(result).toBe(undefined);
    });
    test('should return undefined for n < r values', () => {
        const result = combination(1, 5);
        expect(result).toBe(undefined);
    });
    test('should return undefined for n < 0 values', () => {
        const result = combination(-7, 5);
        expect(result).toBe(undefined);
    });
    test('should return undefined for r < 0 values', () => {
        const result = combination(7, -5);
        expect(result).toBe(undefined);
    });
});