import assert from 'node:assert'; import lodashStable from 'lodash'; import { identity, falsey, stubArray, document, noop, LARGE_ARRAY_SIZE, square } from './utils'; import map from '../src/map'; describe('map', () => { const array = [1, 2]; it('should map values in `collection` to a new array', () => { const object = { a: 1, b: 2 }, expected = ['1', '2']; assert.deepStrictEqual(map(array, String), expected); assert.deepStrictEqual(map(object, String), expected); }); it('should work with `_.property` shorthands', () => { const objects = [{ a: 'x' }, { a: 'y' }]; assert.deepStrictEqual(map(objects, 'a'), ['x', 'y']); }); it('should iterate over own string keyed properties of objects', () => { function Foo() { this.a = 1; } Foo.prototype.b = 2; const actual = map(new Foo(), identity); assert.deepStrictEqual(actual, [1]); }); it('should use `_.identity` when `iteratee` is nullish', () => { const object = { a: 1, b: 2 }, values = [, null, undefined], expected = lodashStable.map(values, lodashStable.constant([1, 2])); lodashStable.each([array, object], (collection) => { const actual = lodashStable.map(values, (value, index) => index ? map(collection, value) : map(collection), ); assert.deepStrictEqual(actual, expected); }); }); it('should accept a falsey `collection`', () => { const expected = lodashStable.map(falsey, stubArray); const actual = lodashStable.map(falsey, (collection, index) => { try { return index ? map(collection) : map(); } catch (e) {} }); assert.deepStrictEqual(actual, expected); }); it('should treat number values for `collection` as empty', () => { assert.deepStrictEqual(map(1), []); }); it('should treat a nodelist as an array-like object', () => { if (document) { const actual = map(document.getElementsByTagName('body'), (element) => element.nodeName.toLowerCase(), ); assert.deepStrictEqual(actual, ['body']); } }); it('should work with objects with non-number length properties', () => { const value = { value: 'x' }, object = { length: { value: 'x' } }; assert.deepStrictEqual(map(object, identity), [value]); }); it('should return a wrapped value when chaining', () => { assert.ok(_(array).map(noop) instanceof _); }); it('should provide correct `predicate` arguments in a lazy sequence', () => { let args, array = lodashStable.range(LARGE_ARRAY_SIZE + 1), expected = [1, 0, map(array.slice(1), square)]; _(array) .slice(1) .map(function (value, index, array) { args || (args = slice.call(arguments)); }) .value(); assert.deepEqual(args, [1, 0, array.slice(1)]); args = undefined; _(array) .slice(1) .map(square) .map(function (value, index, array) { args || (args = slice.call(arguments)); }) .value(); assert.deepEqual(args, expected); args = undefined; _(array) .slice(1) .map(square) .map(function (value, index) { args || (args = slice.call(arguments)); }) .value(); assert.deepEqual(args, expected); args = undefined; _(array) .slice(1) .map(square) .map(function (value) { args || (args = slice.call(arguments)); }) .value(); assert.deepEqual(args, [1]); args = undefined; _(array) .slice(1) .map(square) .map(function () { args || (args = slice.call(arguments)); }) .value(); assert.deepEqual(args, expected); }); });