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base64.mjs
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base64.mjs
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/**
* base64.ts
*
* Licensed under the BSD 3-Clause License.
* http://opensource.org/licenses/BSD-3-Clause
*
* References:
* http://en.wikipedia.org/wiki/Base64
*
* @author Dan Kogai (https://github.com/dankogai)
*/
const version = '3.7.2';
/**
* @deprecated use lowercase `version`.
*/
const VERSION = version;
const _hasatob = typeof atob === 'function';
const _hasbtoa = typeof btoa === 'function';
const _hasBuffer = typeof Buffer === 'function';
const _TD = typeof TextDecoder === 'function' ? new TextDecoder() : undefined;
const _TE = typeof TextEncoder === 'function' ? new TextEncoder() : undefined;
const b64ch = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
const b64chs = Array.prototype.slice.call(b64ch);
const b64tab = ((a) => {
let tab = {};
a.forEach((c, i) => tab[c] = i);
return tab;
})(b64chs);
const b64re = /^(?:[A-Za-z\d+\/]{4})*?(?:[A-Za-z\d+\/]{2}(?:==)?|[A-Za-z\d+\/]{3}=?)?$/;
const _fromCC = String.fromCharCode.bind(String);
const _U8Afrom = typeof Uint8Array.from === 'function'
? Uint8Array.from.bind(Uint8Array)
: (it, fn = (x) => x) => new Uint8Array(Array.prototype.slice.call(it, 0).map(fn));
const _mkUriSafe = (src) => src
.replace(/=/g, '').replace(/[+\/]/g, (m0) => m0 == '+' ? '-' : '_');
const _tidyB64 = (s) => s.replace(/[^A-Za-z0-9\+\/]/g, '');
/**
* polyfill version of `btoa`
*/
const btoaPolyfill = (bin) => {
// console.log('polyfilled');
let u32, c0, c1, c2, asc = '';
const pad = bin.length % 3;
for (let i = 0; i < bin.length;) {
if ((c0 = bin.charCodeAt(i++)) > 255 ||
(c1 = bin.charCodeAt(i++)) > 255 ||
(c2 = bin.charCodeAt(i++)) > 255)
throw new TypeError('invalid character found');
u32 = (c0 << 16) | (c1 << 8) | c2;
asc += b64chs[u32 >> 18 & 63]
+ b64chs[u32 >> 12 & 63]
+ b64chs[u32 >> 6 & 63]
+ b64chs[u32 & 63];
}
return pad ? asc.slice(0, pad - 3) + "===".substring(pad) : asc;
};
/**
* does what `window.btoa` of web browsers do.
* @param {String} bin binary string
* @returns {string} Base64-encoded string
*/
const _btoa = _hasbtoa ? (bin) => btoa(bin)
: _hasBuffer ? (bin) => Buffer.from(bin, 'binary').toString('base64')
: btoaPolyfill;
const _fromUint8Array = _hasBuffer
? (u8a) => Buffer.from(u8a).toString('base64')
: (u8a) => {
// cf. https://stackoverflow.com/questions/12710001/how-to-convert-uint8-array-to-base64-encoded-string/12713326#12713326
const maxargs = 0x1000;
let strs = [];
for (let i = 0, l = u8a.length; i < l; i += maxargs) {
strs.push(_fromCC.apply(null, u8a.subarray(i, i + maxargs)));
}
return _btoa(strs.join(''));
};
/**
* converts a Uint8Array to a Base64 string.
* @param {boolean} [urlsafe] URL-and-filename-safe a la RFC4648 §5
* @returns {string} Base64 string
*/
const fromUint8Array = (u8a, urlsafe = false) => urlsafe ? _mkUriSafe(_fromUint8Array(u8a)) : _fromUint8Array(u8a);
// This trick is found broken https://github.com/dankogai/js-base64/issues/130
// const utob = (src: string) => unescape(encodeURIComponent(src));
// reverting good old fationed regexp
const cb_utob = (c) => {
if (c.length < 2) {
var cc = c.charCodeAt(0);
return cc < 0x80 ? c
: cc < 0x800 ? (_fromCC(0xc0 | (cc >>> 6))
+ _fromCC(0x80 | (cc & 0x3f)))
: (_fromCC(0xe0 | ((cc >>> 12) & 0x0f))
+ _fromCC(0x80 | ((cc >>> 6) & 0x3f))
+ _fromCC(0x80 | (cc & 0x3f)));
}
else {
var cc = 0x10000
+ (c.charCodeAt(0) - 0xD800) * 0x400
+ (c.charCodeAt(1) - 0xDC00);
return (_fromCC(0xf0 | ((cc >>> 18) & 0x07))
+ _fromCC(0x80 | ((cc >>> 12) & 0x3f))
+ _fromCC(0x80 | ((cc >>> 6) & 0x3f))
+ _fromCC(0x80 | (cc & 0x3f)));
}
};
const re_utob = /[\uD800-\uDBFF][\uDC00-\uDFFFF]|[^\x00-\x7F]/g;
/**
* @deprecated should have been internal use only.
* @param {string} src UTF-8 string
* @returns {string} UTF-16 string
*/
const utob = (u) => u.replace(re_utob, cb_utob);
//
const _encode = _hasBuffer
? (s) => Buffer.from(s, 'utf8').toString('base64')
: _TE
? (s) => _fromUint8Array(_TE.encode(s))
: (s) => _btoa(utob(s));
/**
* converts a UTF-8-encoded string to a Base64 string.
* @param {boolean} [urlsafe] if `true` make the result URL-safe
* @returns {string} Base64 string
*/
const encode = (src, urlsafe = false) => urlsafe
? _mkUriSafe(_encode(src))
: _encode(src);
/**
* converts a UTF-8-encoded string to URL-safe Base64 RFC4648 §5.
* @returns {string} Base64 string
*/
const encodeURI = (src) => encode(src, true);
// This trick is found broken https://github.com/dankogai/js-base64/issues/130
// const btou = (src: string) => decodeURIComponent(escape(src));
// reverting good old fationed regexp
const re_btou = /[\xC0-\xDF][\x80-\xBF]|[\xE0-\xEF][\x80-\xBF]{2}|[\xF0-\xF7][\x80-\xBF]{3}/g;
const cb_btou = (cccc) => {
switch (cccc.length) {
case 4:
var cp = ((0x07 & cccc.charCodeAt(0)) << 18)
| ((0x3f & cccc.charCodeAt(1)) << 12)
| ((0x3f & cccc.charCodeAt(2)) << 6)
| (0x3f & cccc.charCodeAt(3)), offset = cp - 0x10000;
return (_fromCC((offset >>> 10) + 0xD800)
+ _fromCC((offset & 0x3FF) + 0xDC00));
case 3:
return _fromCC(((0x0f & cccc.charCodeAt(0)) << 12)
| ((0x3f & cccc.charCodeAt(1)) << 6)
| (0x3f & cccc.charCodeAt(2)));
default:
return _fromCC(((0x1f & cccc.charCodeAt(0)) << 6)
| (0x3f & cccc.charCodeAt(1)));
}
};
/**
* @deprecated should have been internal use only.
* @param {string} src UTF-16 string
* @returns {string} UTF-8 string
*/
const btou = (b) => b.replace(re_btou, cb_btou);
/**
* polyfill version of `atob`
*/
const atobPolyfill = (asc) => {
// console.log('polyfilled');
asc = asc.replace(/\s+/g, '');
if (!b64re.test(asc))
throw new TypeError('malformed base64.');
asc += '=='.slice(2 - (asc.length & 3));
let u24, bin = '', r1, r2;
for (let i = 0; i < asc.length;) {
u24 = b64tab[asc.charAt(i++)] << 18
| b64tab[asc.charAt(i++)] << 12
| (r1 = b64tab[asc.charAt(i++)]) << 6
| (r2 = b64tab[asc.charAt(i++)]);
bin += r1 === 64 ? _fromCC(u24 >> 16 & 255)
: r2 === 64 ? _fromCC(u24 >> 16 & 255, u24 >> 8 & 255)
: _fromCC(u24 >> 16 & 255, u24 >> 8 & 255, u24 & 255);
}
return bin;
};
/**
* does what `window.atob` of web browsers do.
* @param {String} asc Base64-encoded string
* @returns {string} binary string
*/
const _atob = _hasatob ? (asc) => atob(_tidyB64(asc))
: _hasBuffer ? (asc) => Buffer.from(asc, 'base64').toString('binary')
: atobPolyfill;
//
const _toUint8Array = _hasBuffer
? (a) => _U8Afrom(Buffer.from(a, 'base64'))
: (a) => _U8Afrom(_atob(a), c => c.charCodeAt(0));
/**
* converts a Base64 string to a Uint8Array.
*/
const toUint8Array = (a) => _toUint8Array(_unURI(a));
//
const _decode = _hasBuffer
? (a) => Buffer.from(a, 'base64').toString('utf8')
: _TD
? (a) => _TD.decode(_toUint8Array(a))
: (a) => btou(_atob(a));
const _unURI = (a) => _tidyB64(a.replace(/[-_]/g, (m0) => m0 == '-' ? '+' : '/'));
/**
* converts a Base64 string to a UTF-8 string.
* @param {String} src Base64 string. Both normal and URL-safe are supported
* @returns {string} UTF-8 string
*/
const decode = (src) => _decode(_unURI(src));
/**
* check if a value is a valid Base64 string
* @param {String} src a value to check
*/
const isValid = (src) => {
if (typeof src !== 'string')
return false;
const s = src.replace(/\s+/g, '').replace(/={0,2}$/, '');
return !/[^\s0-9a-zA-Z\+/]/.test(s) || !/[^\s0-9a-zA-Z\-_]/.test(s);
};
//
const _noEnum = (v) => {
return {
value: v, enumerable: false, writable: true, configurable: true
};
};
/**
* extend String.prototype with relevant methods
*/
const extendString = function () {
const _add = (name, body) => Object.defineProperty(String.prototype, name, _noEnum(body));
_add('fromBase64', function () { return decode(this); });
_add('toBase64', function (urlsafe) { return encode(this, urlsafe); });
_add('toBase64URI', function () { return encode(this, true); });
_add('toBase64URL', function () { return encode(this, true); });
_add('toUint8Array', function () { return toUint8Array(this); });
};
/**
* extend Uint8Array.prototype with relevant methods
*/
const extendUint8Array = function () {
const _add = (name, body) => Object.defineProperty(Uint8Array.prototype, name, _noEnum(body));
_add('toBase64', function (urlsafe) { return fromUint8Array(this, urlsafe); });
_add('toBase64URI', function () { return fromUint8Array(this, true); });
_add('toBase64URL', function () { return fromUint8Array(this, true); });
};
/**
* extend Builtin prototypes with relevant methods
*/
const extendBuiltins = () => {
extendString();
extendUint8Array();
};
const gBase64 = {
version: version,
VERSION: VERSION,
atob: _atob,
atobPolyfill: atobPolyfill,
btoa: _btoa,
btoaPolyfill: btoaPolyfill,
fromBase64: decode,
toBase64: encode,
encode: encode,
encodeURI: encodeURI,
encodeURL: encodeURI,
utob: utob,
btou: btou,
decode: decode,
isValid: isValid,
fromUint8Array: fromUint8Array,
toUint8Array: toUint8Array,
extendString: extendString,
extendUint8Array: extendUint8Array,
extendBuiltins: extendBuiltins,
};
// makecjs:CUT //
export { version };
export { VERSION };
export { _atob as atob };
export { atobPolyfill };
export { _btoa as btoa };
export { btoaPolyfill };
export { decode as fromBase64 };
export { encode as toBase64 };
export { utob };
export { encode };
export { encodeURI };
export { encodeURI as encodeURL };
export { btou };
export { decode };
export { isValid };
export { fromUint8Array };
export { toUint8Array };
export { extendString };
export { extendUint8Array };
export { extendBuiltins };
// and finally,
export { gBase64 as Base64 };