123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218 |
- var hasStrictMode = require('has-strict-mode')();
- var global = Function('return this')(); // eslint-disable-line no-new-func
- var identity = function (x) { return x; };
- var canDistinguishSparseFromUndefined = 0 in [undefined]; // IE 6 - 8 have a bug where this returns false.
- var undefinedIfNoSparseBug = canDistinguishSparseFromUndefined ? undefined : { valueOf: function () { return 0; } };
- var createArrayLikeFromArray = function createArrayLike(arr) {
- var o = {};
- for (var i = 0; i < arr.length; i += 1) {
- if (i in arr) {
- o[i] = arr[i];
- }
- }
- o.length = arr.length;
- return o;
- };
- module.exports = function (reduce, t) {
- t.test('passes the correct values to the callback', function (st) {
- st.plan(7);
- var expectedValue = {};
- var initialValue = {};
- var expectedResult = {};
- var arr = [expectedValue];
- var result = reduce(
- arr,
- function (accumulator, value, key, list) {
- st.equal(arguments.length, 4);
- st.equal(accumulator, initialValue, 'first argument is the accumulator');
- st.equal(value, expectedValue, 'second argument is the value');
- st.equal(key, 0, 'third argument is the index');
- st.equal(list, arr, 'fourth argument is the array being iterated');
- st.equal(this, global, 'sloppy: receiver is the expected value');
- return expectedResult;
- },
- initialValue
- );
- st.equal(result, expectedResult, 'result is last return value of accumulator');
- st.end();
- });
- t.test('strict mode callback receiver', { skip: !hasStrictMode }, function (st) {
- reduce(
- [null],
- function () {
- 'use strict';
- st.equal(this, undefined, 'strict: receiver is the expected value');
- }
- );
- st.end();
- });
- t.test('starts with the right initialValue', function (st) {
- var firstValue = {};
- var secondValue = {};
- reduce(
- [firstValue, secondValue],
- function (accumulator, value) {
- st.equal(accumulator, firstValue, 'accumulator starts out as the first value when initialValue is omitted');
- st.equal(value, secondValue, 'value starts out as the second value when initialValue is omitted');
- }
- );
- reduce(
- [secondValue],
- function (accumulator, value) {
- st.equal(accumulator, firstValue, 'accumulator starts out as the initialValue when provided');
- st.equal(value, secondValue, 'value starts out as the first value when initialValue is provided');
- },
- firstValue
- );
- st.end();
- });
- t.test('does not visit elements added to the array after it has begun', function (st) {
- st.plan(8);
- var arr = [1, 2, 3];
- var i = 0;
- reduce(arr, function (acc, v) {
- i += 1;
- arr.push(v + 3);
- });
- st.deepEqual(arr, [1, 2, 3, 5, 6], 'array has received 3 new elements. initialValue omitted');
- st.equal(i, 2, 'reduce callback only called twice');
- i = 0;
- arr = [1, 2, 3];
- reduce(
- arr,
- function (acc, v) {
- i += 1;
- arr.push(v + 3);
- },
- null
- );
- st.deepEqual(arr, [1, 2, 3, 4, 5, 6], 'array has received 3 new elements. initialValue provided');
- st.equal(i, 3, 'reduce callback only called thrice');
- var arrayLike = createArrayLikeFromArray([1, 2, 3]);
- i = 0;
- reduce(arrayLike, function (acc, v) {
- i += 1;
- arrayLike[arrayLike.length] = v + 3;
- arrayLike.length += 1;
- });
- st.deepEqual(Array.prototype.slice.call(arrayLike), [1, 2, 3, 5, 6], 'arrayLike has received 3 new elements. initialValue omitted');
- st.equal(i, 2, 'reduce callback only called twice');
- arrayLike = createArrayLikeFromArray([1, 2, 3]);
- i = 0;
- reduce(
- arrayLike,
- function (acc, v) {
- i += 1;
- arrayLike[arrayLike.length] = v + 3;
- arrayLike.length += 1;
- },
- null
- );
- st.deepEqual(Array.prototype.slice.call(arrayLike), [1, 2, 3, 4, 5, 6], 'arrayLike has received 3 new elements. initialValue provided');
- st.equal(i, 3, 'reduce callback only called thrice');
- st.end();
- });
- t.test('empty array', function (st) {
- var initialValue = {};
- var actual = reduce([], identity, initialValue);
- st.equal(actual, initialValue, 'empty array returns callback return');
- st['throws'](
- function () { reduce([], identity); },
- TypeError,
- 'empty array with omitted initialValue throws'
- );
- var sparse = Array(10);
- st['throws'](
- function () { reduce(sparse, identity); },
- TypeError,
- 'only-holes array with omitted initialValue throws (test262: 15.4.4.21-8-c-1)'
- );
- st.end();
- });
- t.test('skips holes', function (st) {
- var arr = [1, undefinedIfNoSparseBug, 3];
- var visited = {};
- reduce(
- arr,
- function (a, b) {
- if (a) { visited[a] = true; }
- if (b) { visited[b] = true; }
- return 0;
- },
- null
- );
- st.deepEqual(visited, { 1: true, 3: true }, 'only non-holes are visited; initialValue provided');
- visited = {};
- reduce(
- arr,
- function (a, b) {
- if (a) { visited[a] = true; }
- if (b) { visited[b] = true; }
- return 0;
- }
- );
- st.deepEqual(visited, { 1: true, 3: true }, 'only non-holes are visited; initialValue omitted');
- st.end();
- });
- t.test('list arg boxing', function (st) {
- st.plan(4);
- reduce(
- 'f',
- function (acc, item, index, list) {
- st.equal(acc, null, 'accumulator matches');
- st.equal(item, 'f', 'letter matches');
- st.equal(typeof list, 'object', 'primitive list arg is boxed');
- st.equal(Object.prototype.toString.call(list), '[object String]', 'boxed list arg is a String');
- },
- null
- );
- st.end();
- });
- t.test('test262: 15.4.4.21-3-12', function (st) {
- var obj = {
- 1: 11,
- 2: 9,
- length: '-4294967294'
- };
- var cb = function callbackfn(prevVal, curVal, idx, object) {
- st.equal(object, obj, '4th argument is receiver');
- return curVal === 11 && idx === 1;
- };
- st.equal(reduce(obj, cb, 1), 1, 'reduce(obj, callbackfn, 1)');
- st.end();
- });
- };
|