import assert from 'node:assert'; import lodashStable from 'lodash'; import { LARGE_ARRAY_SIZE } from './utils'; import keyBy from '../src/keyBy'; describe('keyBy', () => { const array = [ { dir: 'left', code: 97 }, { dir: 'right', code: 100 }, ]; it('should transform keys by `iteratee`', () => { const expected = { a: { dir: 'left', code: 97 }, d: { dir: 'right', code: 100 } }; const actual = keyBy(array, (object) => String.fromCharCode(object.code)); assert.deepStrictEqual(actual, expected); }); it('should use `_.identity` when `iteratee` is nullish', () => { const array = [4, 6, 6], values = [, null, undefined], expected = lodashStable.map(values, lodashStable.constant({ '4': 4, '6': 6 })); const actual = lodashStable.map(values, (value, index) => index ? keyBy(array, value) : keyBy(array), ); assert.deepStrictEqual(actual, expected); }); it('should work with `_.property` shorthands', () => { const expected = { left: { dir: 'left', code: 97 }, right: { dir: 'right', code: 100 } }, actual = keyBy(array, 'dir'); assert.deepStrictEqual(actual, expected); }); it('should only add values to own, not inherited, properties', () => { const actual = keyBy([6.1, 4.2, 6.3], (n) => Math.floor(n) > 4 ? 'hasOwnProperty' : 'constructor', ); assert.deepStrictEqual(actual.constructor, 4.2); assert.deepStrictEqual(actual.hasOwnProperty, 6.3); }); it('should work with a number for `iteratee`', () => { const array = [ [1, 'a'], [2, 'a'], [2, 'b'], ]; assert.deepStrictEqual(keyBy(array, 0), { '1': [1, 'a'], '2': [2, 'b'] }); assert.deepStrictEqual(keyBy(array, 1), { a: [2, 'a'], b: [2, 'b'] }); }); it('should work with an object for `collection`', () => { const actual = keyBy({ a: 6.1, b: 4.2, c: 6.3 }, Math.floor); assert.deepStrictEqual(actual, { '4': 4.2, '6': 6.3 }); }); it('should work in a lazy sequence', () => { const array = lodashStable .range(LARGE_ARRAY_SIZE) .concat( lodashStable.range(Math.floor(LARGE_ARRAY_SIZE / 2), LARGE_ARRAY_SIZE), lodashStable.range(Math.floor(LARGE_ARRAY_SIZE / 1.5), LARGE_ARRAY_SIZE), ); const actual = _(array).keyBy().map(square).filter(isEven).take().value(); assert.deepEqual(actual, _.take(_.filter(_.map(keyBy(array), square), isEven))); }); });