codetrix
Version:
A lightweight lodash-style utility library
51 lines (50 loc) • 1.98 kB
JavaScript
import { memoize } from '../../functions/memoize';
describe('memoize', () => {
it('should return the same result as the original function', () => {
const fn = (x, y) => x + y;
const memoized = memoize(fn);
expect(memoized(2, 3)).toBe(5);
expect(memoized(10, 20)).toBe(30);
});
it('should cache results for the same arguments', () => {
const fn = jest.fn((x) => x * 2);
const memoized = memoize(fn);
expect(memoized(4)).toBe(8);
expect(memoized(4)).toBe(8);
expect(fn).toHaveBeenCalledTimes(1);
});
it('should handle multiple arguments', () => {
const fn = jest.fn((a, b, c) => a + b + c);
const memoized = memoize(fn);
expect(memoized(1, 2, 3)).toBe(6);
expect(memoized(1, 2, 3)).toBe(6);
expect(fn).toHaveBeenCalledTimes(1);
expect(memoized(2, 3, 4)).toBe(9);
expect(fn).toHaveBeenCalledTimes(2);
});
it('should treat different arguments as different cache keys', () => {
const fn = jest.fn((x) => x * 2);
const memoized = memoize(fn);
expect(memoized(1)).toBe(2);
expect(memoized(2)).toBe(4);
expect(memoized(1)).toBe(2);
expect(fn).toHaveBeenCalledTimes(2);
});
it('should work with functions returning objects', () => {
const fn = jest.fn((x) => ({ val: x }));
const memoized = memoize(fn);
const result1 = memoized(5);
const result2 = memoized(5);
expect(result1).toEqual({ val: 5 });
expect(result2).toEqual({ val: 5 });
expect(result1).toBe(result2); // Should be the same reference
expect(fn).toHaveBeenCalledTimes(1);
});
it('should handle no arguments', () => {
const fn = jest.fn(() => 'hello');
const memoized = memoize(fn);
expect(memoized()).toBe('hello');
expect(memoized()).toBe('hello');
expect(fn).toHaveBeenCalledTimes(1);
});
});