import isBoolean from '../../utils/isBoolean'; describe('isBoolean', () => { it('should return true when value is a boolean', () => { expect(isBoolean(true)).toBeTruthy(); expect(isBoolean(false)).toBeTruthy(); }); it('should return false when value is not a boolean', () => { expect(isBoolean(null)).toBeFalsy(); expect(isBoolean(undefined)).toBeFalsy(); expect(isBoolean(-1)).toBeFalsy(); expect(isBoolean(0)).toBeFalsy(); expect(isBoolean(1)).toBeFalsy(); expect(isBoolean('')).toBeFalsy(); expect(isBoolean({})).toBeFalsy(); expect(isBoolean([])).toBeFalsy(); expect(isBoolean(() => null)).toBeFalsy(); }); });