rename Array.prototype.flatten to Array.prototype.flat, fixes #405

tc39/proposal-flatMap@093eacc7fe0906e70f7626bf
6c7d6e9dfc53cce9

README.md

@@ -12,31 +12,31 @@ Modular standard library for JavaScript. Includes polyfills for [ECMAScript 5, 2
 import 'core-js'; // <- at the top of your entry point
 
 Array.from(new Set([1, 2, 3, 2, 1]));          // => [1, 2, 3]
-[1, [2, 3], [4, [5]]].flatten(2);              // => [1, 2, 3, 4, 5]
+[1, [2, 3], [4, [5]]].flat(2);                 // => [1, 2, 3, 4, 5]
 Promise.resolve(32).then(x => console.log(x)); // => 32
 ```
 
 *You can load only required features*:
 ```js
-import 'core-js/features/array/from';    // <- at the top of your entry point
-import 'core-js/features/array/flatten'; // <- at the top of your entry point
-import 'core-js/features/set';           // <- at the top of your entry point
-import 'core-js/features/promise';       // <- at the top of your entry point
+import 'core-js/features/array/from'; // <- at the top of your entry point
+import 'core-js/features/array/flat'; // <- at the top of your entry point
+import 'core-js/features/set';        // <- at the top of your entry point
+import 'core-js/features/promise';    // <- at the top of your entry point
 
 Array.from(new Set([1, 2, 3, 2, 1]));          // => [1, 2, 3]
-[1, [2, 3], [4, [5]]].flatten(2);              // => [1, 2, 3, 4, 5]
+[1, [2, 3], [4, [5]]].flat(2);                 // => [1, 2, 3, 4, 5]
 Promise.resolve(32).then(x => console.log(x)); // => 32
 ```
 
 *Or use it without global namespace pollution*:
 ```js
 import from from 'core-js-pure/features/array/from';
-import flatten from 'core-js-pure/features/array/flatten';
+import flat from 'core-js-pure/features/array/flat';
 import Set from 'core-js-pure/features/set';
 import Promise from 'core-js-pure/features/promise';
 
 from(new Set([1, 2, 3, 2, 1]));                // => [1, 2, 3]
-flatten([1, [2, 3], [4, [5]]], 2);             // => [1, 2, 3, 4, 5]
+flat([1, [2, 3], [4, [5]]], 2);                // => [1, 2, 3, 4, 5]
 Promise.resolve(32).then(x => console.log(x)); // => 32
 ```
 
@@ -1421,25 +1421,25 @@ None.
 ```js
 core-js(-pure)/stage/3
 ```
-* `Array#flatten` and `Array#flatMap` [proposal](https://tc39.github.io/proposal-flatMap) - modules [`esnext.array.flatten`](https://github.com/zloirock/core-js/blob/v3/packages/core-js/modules/esnext.array.flatten.js) and [`esnext.array.flat-map`](https://github.com/zloirock/core-js/blob/v3/packages/core-js/modules/esnext.array.flat-map.js)
+* `Array#flat` and `Array#flatMap` [proposal](https://tc39.github.io/proposal-flatMap) - modules [`esnext.array.flat`](https://github.com/zloirock/core-js/blob/v3/packages/core-js/modules/esnext.array.flat.js) and [`esnext.array.flat-map`](https://github.com/zloirock/core-js/blob/v3/packages/core-js/modules/esnext.array.flat-map.js)
 ```js
 class Array {
-  flatten(depthArg?: number = 1): Array<mixed>;
+  flat(depthArg?: number = 1): Array<mixed>;
   flatMap(mapFn: (value: any, index: number, target: any) => any, thisArg: any): Array<mixed>;
 }
 ```
 [*CommonJS entry points:*](#commonjs)
 ```js
-core-js(-pure)/features/array/flatten
+core-js(-pure)/features/array/flat
 core-js(-pure)/features/array/flat-map
-core-js(-pure)/features/array/virtual/flatten
+core-js(-pure)/features/array/virtual/flat
 core-js(-pure)/features/array/virtual/flat-map
 ```
 [*Examples*](https://goo.gl/jTXsZi):
 ```js
-[1, [2, 3], [4, 5]].flatten();    // => [1, 2, 3, 4, 5]
-[1, [2, [3, [4]]], 5].flatten();  // => [1, 2, [3, [4]], 5]
-[1, [2, [3, [4]]], 5].flatten(3); // => [1, 2, 3, 4, 5]
+[1, [2, 3], [4, 5]].flat();    // => [1, 2, 3, 4, 5]
+[1, [2, [3, [4]]], 5].flat();  // => [1, 2, [3, [4]], 5]
+[1, [2, [3, [4]]], 5].flat(3); // => [1, 2, 3, 4, 5]
 
 [{ a: 1, b: 2 }, { a: 3, b: 4 }, { a: 5, b: 6 }].flatMap(it => [it.a, it.b]); // => [1, 2, 3, 4, 5, 6]
 ```

packages/core-js-builder/config.js

@@ -191,7 +191,7 @@ module.exports = {
     'es.reflect.prevent-extensions',
     'es.reflect.set',
     'es.reflect.set-prototype-of',
-    'esnext.array.flatten',
+    'esnext.array.flat',
     'esnext.array.flat-map',
     'esnext.array.last-index',
     'esnext.array.last-item',

packages/core-js/features/array/flatten.js → packages/core-js/features/array/flat.js

@@ -1,3 +1,3 @@
-require('../../modules/esnext.array.flatten');
+require('../../modules/esnext.array.flat');
 
-module.exports = require('../../internals/entry-unbind')('Array', 'flatten');
+module.exports = require('../../internals/entry-unbind')('Array', 'flat');

packages/core-js/features/array/index.js

@@ -26,6 +26,6 @@ require('../../modules/es.array.includes');
 require('../../modules/esnext.array.last-item');
 require('../../modules/esnext.array.last-index');
 require('../../modules/esnext.array.flat-map');
-require('../../modules/esnext.array.flatten');
+require('../../modules/esnext.array.flat');
 
 module.exports = require('../../internals/path').Array;

packages/core-js/features/array/virtual/flatten.js → packages/core-js/features/array/virtual/flat.js

@@ -1,3 +1,3 @@
-require('../../../modules/esnext.array.flatten');
+require('../../../modules/esnext.array.flat');
 
-module.exports = require('../../../internals/entry-virtual')('Array').flatten;
+module.exports = require('../../../internals/entry-virtual')('Array').flat;

packages/core-js/features/array/virtual/index.js

@@ -19,7 +19,7 @@ require('../../../modules/es.array.sort');
 require('../../../modules/es.array.splice');
 require('../../../modules/es.array.species');
 require('../../../modules/es.array.iterator');
-require('../../../modules/esnext.array.flatten');
+require('../../../modules/esnext.array.flat');
 require('../../../modules/esnext.array.flat-map');
 
 module.exports = require('../../../internals/entry-virtual')('Array');

packages/core-js/index.js

@@ -188,7 +188,7 @@ require('./modules/es.reflect.own-keys');
 require('./modules/es.reflect.prevent-extensions');
 require('./modules/es.reflect.set');
 require('./modules/es.reflect.set-prototype-of');
-require('./modules/esnext.array.flatten');
+require('./modules/esnext.array.flat');
 require('./modules/esnext.array.flat-map');
 require('./modules/esnext.array.last-index');
 require('./modules/esnext.array.last-item');

packages/core-js/modules/esnext.array.flatten.js → packages/core-js/modules/esnext.array.flat.js

@@ -5,10 +5,10 @@ var toLength = require('../internals/to-length');
 var toInteger = require('../internals/to-integer');
 var arraySpeciesCreate = require('../internals/array-species-create');
 
-// `Array.prototype.flatten` method
-// https://tc39.github.io/proposal-flatMap/#sec-Array.prototype.flatten
+// `Array.prototype.flat` method
+// https://tc39.github.io/proposal-flatMap/#sec-Array.prototype.flat
 require('../internals/export')({ target: 'Array', proto: true }, {
-  flatten: function flatten(/* depthArg = 1 */) {
+  flat: function flat(/* depthArg = 1 */) {
     var depthArg = arguments[0];
     var O = toObject(this);
     var sourceLen = toLength(O.length);
@@ -18,4 +18,4 @@ require('../internals/export')({ target: 'Array', proto: true }, {
   }
 });
 
-require('../internals/add-to-unscopables')('flatten');
+require('../internals/add-to-unscopables')('flat');

packages/core-js/stage/3.js

@@ -1,4 +1,4 @@
-require('../modules/esnext.array.flatten');
+require('../modules/esnext.array.flat');
 require('../modules/esnext.array.flat-map');
 require('../modules/esnext.global');
 require('../modules/esnext.string.match-all');

tests/commonjs.js

@@ -61,6 +61,8 @@ for (const _PATH of ['../packages/core-js-pure', '../packages/core-js']) {
   ok(typeof load('features/array/for-each') === 'function');
   ok(typeof load('features/array/map') === 'function');
   ok(typeof load('features/array/filter') === 'function');
+  ok(typeof load('features/array/flat') === 'function');
+  ok(typeof load('features/array/flat-map') === 'function');
   ok(typeof load('features/array/some') === 'function');
   ok(typeof load('features/array/every') === 'function');
   ok(typeof load('features/array/reduce') === 'function');
@@ -86,6 +88,8 @@ for (const _PATH of ['../packages/core-js-pure', '../packages/core-js']) {
   ok(typeof load('features/array/virtual/for-each') === 'function');
   ok(typeof load('features/array/virtual/map') === 'function');
   ok(typeof load('features/array/virtual/filter') === 'function');
+  ok(typeof load('features/array/virtual/flat') === 'function');
+  ok(typeof load('features/array/virtual/flat-map') === 'function');
   ok(typeof load('features/array/virtual/some') === 'function');
   ok(typeof load('features/array/virtual/every') === 'function');
   ok(typeof load('features/array/virtual/reduce') === 'function');

tests/pure/esnext.array.flat.js

@@ -0,0 +1,28 @@
+import { DESCRIPTORS, STRICT } from '../helpers/constants';
+
+import flat from 'core-js-pure/features/array/flat';
+import defineProperty from 'core-js-pure/features/object/define-property';
+
+QUnit.test('Array#flat', assert => {
+  assert.isFunction(flat);
+  assert.deepEqual(flat([]), []);
+  const array = [1, [2, 3], [4, [5, 6]]];
+  assert.deepEqual(flat(array, 0), array);
+  assert.deepEqual(flat(array, 1), [1, 2, 3, 4, [5, 6]]);
+  assert.deepEqual(flat(array), [1, 2, 3, 4, [5, 6]]);
+  assert.deepEqual(flat(array, 2), [1, 2, 3, 4, 5, 6]);
+  assert.deepEqual(flat(array, 3), [1, 2, 3, 4, 5, 6]);
+  assert.deepEqual(flat(array, -1), array);
+  assert.deepEqual(flat(array, Infinity), [1, 2, 3, 4, 5, 6]);
+  if (STRICT) {
+    assert.throws(() => flat(null), TypeError);
+    assert.throws(() => flat(undefined), TypeError);
+  }
+  if (DESCRIPTORS) {
+    assert.notThrows(() => flat(defineProperty({ length: -1 }, 0, {
+      get() {
+        throw new Error();
+      },
+    })).length === 0, 'uses ToLength');
+  }
+});

tests/pure/index.js

@@ -130,7 +130,7 @@ import './es.weak-set';
 
 QUnit.module('ESNext');
 import './esnext.array.flat-map';
-import './esnext.array.flatten';
+import './esnext.array.flat';
 import './esnext.asap';
 import './esnext.composite-key';
 import './esnext.composite-symbol';

tests/tests/esnext.array.flat.js

@@ -0,0 +1,32 @@
+import { DESCRIPTORS, STRICT } from '../helpers/constants';
+
+QUnit.test('Array#flat', assert => {
+  const { flat } = Array.prototype;
+  const { defineProperty } = Object;
+  assert.isFunction(flat);
+  assert.name(flat, 'flat');
+  assert.arity(flat, 0);
+  assert.looksNative(flat);
+  assert.nonEnumerable(Array.prototype, 'flat');
+  assert.deepEqual([].flat(), []);
+  const array = [1, [2, 3], [4, [5, 6]]];
+  assert.deepEqual(array.flat(0), array);
+  assert.deepEqual(array.flat(1), [1, 2, 3, 4, [5, 6]]);
+  assert.deepEqual(array.flat(), [1, 2, 3, 4, [5, 6]]);
+  assert.deepEqual(array.flat(2), [1, 2, 3, 4, 5, 6]);
+  assert.deepEqual(array.flat(3), [1, 2, 3, 4, 5, 6]);
+  assert.deepEqual(array.flat(-1), array);
+  assert.deepEqual(array.flat(Infinity), [1, 2, 3, 4, 5, 6]);
+  if (STRICT) {
+    assert.throws(() => flat.call(null), TypeError);
+    assert.throws(() => flat.call(undefined), TypeError);
+  }
+  if (DESCRIPTORS) {
+    assert.notThrows(() => flat.call(defineProperty({ length: -1 }, 0, {
+      get() {
+        throw new Error();
+      },
+    })).length === 0, 'uses ToLength');
+  }
+  assert.ok('flat' in Array.prototype[Symbol.unscopables], 'In Array#@@unscopables');
+});

tests/tests/index.js

@@ -180,7 +180,7 @@ QUnit.module('ESNext');
 import './esnext.array.last-item';
 import './esnext.array.last-index';
 import './esnext.array.flat-map';
-import './esnext.array.flatten';
+import './esnext.array.flat';
 import './esnext.asap';
 import './esnext.composite-key';
 import './esnext.composite-symbol';