import lodashStable from 'lodash'; import { stubZero, falsey } from './utils'; import indexOf from '../src/indexOf'; describe('indexOf', () => { const array = [1, 2, 3, 1, 2, 3]; it('`_.indexOf` should return the index of the first matched value', () => { expect(indexOf(array, 3)).toBe(2); }); it('`_.indexOf` should work with a positive `fromIndex`', () => { expect(indexOf(array, 1, 2)).toBe(3); }); it('`_.indexOf` should work with a `fromIndex` >= `length`', () => { const values = [6, 8, 2 ** 32, Infinity]; const expected = lodashStable.map(values, lodashStable.constant([-1, -1, -1])); const actual = lodashStable.map(values, (fromIndex) => [ indexOf(array, undefined, fromIndex), indexOf(array, 1, fromIndex), indexOf(array, '', fromIndex), ]); expect(actual).toEqual(expected); }); it('`_.indexOf` should work with a negative `fromIndex`', () => { expect(indexOf(array, 2, -3)).toBe(4); }); it('`_.indexOf` should work with a negative `fromIndex` <= `-length`', () => { const values = [-6, -8, -Infinity]; const expected = lodashStable.map(values, stubZero); const actual = lodashStable.map(values, (fromIndex) => indexOf(array, 1, fromIndex)); expect(actual).toEqual(expected); }); it('`_.indexOf` should treat falsey `fromIndex` values as `0`', () => { const expected = lodashStable.map(falsey, stubZero); const actual = lodashStable.map(falsey, (fromIndex) => indexOf(array, 1, fromIndex)); expect(actual).toEqual(expected); }); it('`_.indexOf` should coerce `fromIndex` to an integer', () => { expect(indexOf(array, 2, 1.2)).toBe(1); }); });