add .fromBase64 method

packages/core-js/internals/array-from-constructor-and-list.js

@@ -1,9 +1,9 @@
 'use strict';
 var lengthOfArrayLike = require('../internals/length-of-array-like');
 
-module.exports = function (Constructor, list) {
+module.exports = function (Constructor, list, $length) {
   var index = 0;
-  var length = lengthOfArrayLike(list);
+  var length = arguments.length > 2 ? $length : lengthOfArrayLike(list);
   var result = new Constructor(length);
   while (length > index) result[index] = list[index++];
   return result;

packages/core-js/modules/esnext.uint8-array.from-base64.js

@@ -1,16 +1,80 @@
 'use strict';
 var $ = require('../internals/export');
 var global = require('../internals/global');
+var uncurryThis = require('../internals/function-uncurry-this');
 var aString = require('../internals/a-string');
+var isObject = require('../internals/is-object');
+var has = require('../internals/has-own-property');
+var arrayFromConstructorAndList = require('../internals/array-from-constructor-and-list');
+var base64Map = require('../internals/base64-map');
+
+var base64Alphabet = base64Map.c2i;
+var base64UrlAlphabet = base64Map.c2iUrl;
 
 var Uint8Array = global.Uint8Array;
+var SyntaxError = global.SyntaxError;
+var TypeError = global.TypeError;
+var charAt = uncurryThis(''.charAt);
+var replace = uncurryThis(''.replace);
+var stringSlice = uncurryThis(''.slice);
+var push = uncurryThis([].push);
+var SPACES = /[\t\n\f\r ]/g;
+var BASE64 = 'base64';
+var EXTRA_BITS = 'Extra bits';
 
 // `Uint8Array.fromBase64` method
 // https://github.com/tc39/proposal-arraybuffer-base64
 if (Uint8Array) $({ target: 'Uint8Array', stat: true, forced: true }, {
-  fromBase64: function fromBase64(string) {
+  fromBase64: function fromBase64(string /* , options */) {
     aString(string);
-    // TODO
-    return new Uint8Array(8);
+    var options = arguments.length > 1 ? arguments[1] : undefined;
+    if (options !== undefined && !isObject(options)) throw new TypeError('Incorrect options');
+    var $alphabet = options && options.alphabet;
+    if ($alphabet === undefined) $alphabet = BASE64;
+    if ($alphabet !== BASE64 && $alphabet !== 'base64url') throw new TypeError('Incorrect `alphabet` option');
+    var alphabet = $alphabet === BASE64 ? base64Alphabet : base64UrlAlphabet;
+    var $strict = options ? !!options.strict : false;
+
+    var input = $strict ? string : replace(string, SPACES, '');
+
+    if (input.length % 4 === 0) {
+      if (stringSlice(input, -2) === '==') input = stringSlice(input, 0, -2);
+      else if (stringSlice(input, -1) === '=') input = stringSlice(input, 0, -1);
+    } else if ($strict) throw new SyntaxError('Input is not correctly padded');
+
+    var lastChunkSize = input.length % 4;
+
+    switch (lastChunkSize) {
+      case 1: throw new SyntaxError('Bad input length');
+      case 2: input += 'A'; // break omitted
+      case 3: input += 'A'; // 'AA' for 2
+    }
+
+    var bytes = [];
+    var i = 0;
+    var inputLength = input.length;
+
+    var get = function (shift) {
+      var chr = charAt(input, i + shift);
+      if (!has(alphabet, chr)) throw new SyntaxError('Bad char in input: "' + chr + '"');
+      return alphabet[chr] << (18 - 6 * shift);
+    };
+
+    for (; i < inputLength; i += 4) {
+      var triplet = get(0) + get(1) + get(2) + get(3);
+      push(bytes, (triplet >> 16) & 255, (triplet >> 8) & 255, triplet & 255);
+    }
+
+    var byteLength = bytes.length;
+
+    if (lastChunkSize === 2) {
+      if ($strict && bytes[byteLength - 2] !== 0) throw new SyntaxError(EXTRA_BITS);
+      byteLength -= 2;
+    } else if (lastChunkSize === 3) {
+      if ($strict && bytes[byteLength - 1] !== 0) throw new SyntaxError(EXTRA_BITS);
+      byteLength--;
+    }
+
+    return arrayFromConstructorAndList(Uint8Array, bytes, byteLength);
   }
 });

packages/core-js/modules/esnext.uint8-array.to-base64.js

@@ -17,8 +17,9 @@ var BASE64 = 'base64';
 // `Uint8Array..prototype.toBase64` method
 // https://github.com/tc39/proposal-arraybuffer-base64
 if (Uint8Array) $({ target: 'Uint8Array', proto: true, forced: true }, {
-  toBase64: function toBase64(options) {
+  toBase64: function toBase64(/* options */) {
     var array = anUint8Array(this);
+    var options = arguments.length ? arguments[0] : undefined;
     if (options !== undefined && !isObject(options)) throw new TypeError('Incorrect options');
     var $alphabet = options && options.alphabet;
     if ($alphabet === undefined) $alphabet = BASE64;