225 lines
5.8 KiB
JavaScript

'use strict';
var test = require('tape');
var forEach = require('../');
test('forEach calls each iterator', function (t) {
var count = 0;
t.plan(4);
forEach({ a: 1, b: 2 }, function (value, key) {
if (count === 0) {
t.equal(value, 1);
t.equal(key, 'a');
} else {
t.equal(value, 2);
t.equal(key, 'b');
}
count += 1;
});
});
test('forEach calls iterator with correct this value', function (t) {
var thisValue = {};
t.plan(1);
forEach([0], function () {
t.equal(this, thisValue);
}, thisValue);
});
test('second argument: iterator', function (t) {
/** @type {unknown[]} */
var arr = [];
// @ts-expect-error
t['throws'](function () { forEach(arr); }, TypeError, 'undefined is not a function');
// @ts-expect-error
t['throws'](function () { forEach(arr, null); }, TypeError, 'null is not a function');
// @ts-expect-error
t['throws'](function () { forEach(arr, ''); }, TypeError, 'string is not a function');
// @ts-expect-error
t['throws'](function () { forEach(arr, /a/); }, TypeError, 'regex is not a function');
// @ts-expect-error
t['throws'](function () { forEach(arr, true); }, TypeError, 'true is not a function');
// @ts-expect-error
t['throws'](function () { forEach(arr, false); }, TypeError, 'false is not a function');
// @ts-expect-error
t['throws'](function () { forEach(arr, NaN); }, TypeError, 'NaN is not a function');
// @ts-expect-error
t['throws'](function () { forEach(arr, 42); }, TypeError, '42 is not a function');
t.doesNotThrow(function () { forEach(arr, function () {}); }, 'function is a function');
// @ts-expect-error TODO fixme
t.doesNotThrow(function () { forEach(arr, setTimeout); }, 'setTimeout is a function');
/* eslint-env browser */
if (typeof window !== 'undefined') {
t.doesNotThrow(function () { forEach(arr, window.alert); }, 'alert is a function');
}
t.end();
});
test('array', function (t) {
var arr = /** @type {const} */ ([1, 2, 3]);
t.test('iterates over every item', function (st) {
var index = 0;
forEach(arr, function () { index += 1; });
st.equal(index, arr.length, 'iterates ' + arr.length + ' times');
st.end();
});
t.test('first iterator argument', function (st) {
var index = 0;
st.plan(arr.length);
forEach(arr, function (item) {
st.equal(arr[index], item, 'item ' + index + ' is passed as first argument');
index += 1;
});
st.end();
});
t.test('second iterator argument', function (st) {
var counter = 0;
st.plan(arr.length);
forEach(arr, function (_item, index) {
st.equal(counter, index, 'index ' + index + ' is passed as second argument');
counter += 1;
});
st.end();
});
t.test('third iterator argument', function (st) {
st.plan(arr.length);
forEach(arr, function (_item, _index, array) {
st.deepEqual(arr, array, 'array is passed as third argument');
});
st.end();
});
t.test('context argument', function (st) {
var context = {};
forEach([], function () {
st.equal(this, context, '"this" is the passed context');
}, context);
st.end();
});
t.end();
});
test('object', function (t) {
var obj = {
a: 1,
b: 2,
c: 3
};
var keys = /** @type {const} */ (['a', 'b', 'c']);
/** @constructor */
function F() {
this.a = 1;
this.b = 2;
}
F.prototype.c = 3;
var fKeys = /** @type {const} */ (['a', 'b']);
t.test('iterates over every object literal key', function (st) {
var counter = 0;
forEach(obj, function () { counter += 1; });
st.equal(counter, keys.length, 'iterated ' + counter + ' times');
st.end();
});
t.test('iterates only over own keys', function (st) {
var counter = 0;
forEach(new F(), function () { counter += 1; });
st.equal(counter, fKeys.length, 'iterated ' + fKeys.length + ' times');
st.end();
});
t.test('first iterator argument', function (st) {
var index = 0;
st.plan(keys.length);
forEach(obj, function (item) {
st.equal(obj[keys[index]], item, 'item at key ' + keys[index] + ' is passed as first argument');
index += 1;
});
st.end();
});
t.test('second iterator argument', function (st) {
var counter = 0;
st.plan(keys.length);
forEach(obj, function (_item, key) {
st.equal(keys[counter], key, 'key ' + key + ' is passed as second argument');
counter += 1;
});
st.end();
});
t.test('third iterator argument', function (st) {
st.plan(keys.length);
forEach(obj, function (_item, _key, object) {
st.deepEqual(obj, object, 'object is passed as third argument');
});
st.end();
});
t.test('context argument', function (st) {
var context = {};
forEach({}, function () {
st.equal(this, context, '"this" is the passed context');
}, context);
st.end();
});
t.end();
});
test('string', function (t) {
var str = /** @type {const} */ ('str');
t.test('second iterator argument', function (st) {
var counter = 0;
st.plan((str.length * 2) + 1);
forEach(str, function (item, index) {
st.equal(counter, index, 'index ' + index + ' is passed as second argument');
st.equal(str.charAt(index), item);
counter += 1;
});
st.equal(counter, str.length, 'iterates ' + str.length + ' times');
st.end();
});
t.end();
});