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esnext.uint8-array.from-base64.js
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esnext.uint8-array.from-base64.js
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'use strict';
var $ = require('../internals/export');
var global = require('../internals/global');
var uncurryThis = require('../internals/function-uncurry-this');
var anObjectOrUndefined = require('../internals/an-object-or-undefined');
var aString = require('../internals/a-string');
var hasOwn = require('../internals/has-own-property');
var arrayFromConstructorAndList = require('../internals/array-from-constructor-and-list');
var base64Map = require('../internals/base64-map');
var getAlphabetOption = require('../internals/get-alphabet-option');
var base64Alphabet = base64Map.c2i;
var base64UrlAlphabet = base64Map.c2iUrl;
var Uint8Array = global.Uint8Array;
var SyntaxError = global.SyntaxError;
var charAt = uncurryThis(''.charAt);
var replace = uncurryThis(''.replace);
var stringSlice = uncurryThis(''.slice);
var push = uncurryThis([].push);
var SPACES = /[\t\n\f\r ]/g;
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 /* , options */) {
aString(string);
var options = arguments.length > 1 ? anObjectOrUndefined(arguments[1]) : undefined;
var alphabet = getAlphabetOption(options) === '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 += 'AA'; break;
case 3: input += 'A';
}
var bytes = [];
var i = 0;
var inputLength = input.length;
var at = function (shift) {
var chr = charAt(input, i + shift);
if (!hasOwn(alphabet, chr)) throw new SyntaxError('Bad char in input: "' + chr + '"');
return alphabet[chr] << (18 - 6 * shift);
};
for (; i < inputLength; i += 4) {
var triplet = at(0) + at(1) + at(2) + at(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);
}
});