base64.ts

/**
 *  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 = '3.7.7';
/**
 * @deprecated use lowercase `version`.
 */
const VERSION = version;
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) => new Uint8Array(Array.prototype.slice.call(it, 0));
const _mkUriSafe = (src: string) => src
    .replace(/=/g, '').replace(/[+\/]/g, (m0) => m0 == '+' ? '-' : '_');
const _tidyB64 = (s: string) => s.replace(/[^A-Za-z0-9\+\/]/g, '');
/**
 * polyfill version of `btoa`
 */
const btoaPolyfill = (bin: string) => {
    // 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 = typeof btoa === 'function' ? (bin: string) => btoa(bin)
    : _hasBuffer ? (bin: string) => Buffer.from(bin, 'binary').toString('base64')
        : btoaPolyfill;
const _fromUint8Array = _hasBuffer
    ? (u8a: Uint8Array) => Buffer.from(u8a).toString('base64')
    : (u8a: Uint8Array) => {
        // cf. https://stackoverflow.com/questions/12710001/how-to-convert-uint8-array-to-base64-encoded-string/12713326#12713326
        const maxargs = 0x1000;
        let strs: string[] = [];
        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: Uint8Array, 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: string) => {
    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: string) => u.replace(re_utob, cb_utob);
//
const _encode = _hasBuffer
    ? (s: string) => Buffer.from(s, 'utf8').toString('base64')
    : _TE
        ? (s: string) => _fromUint8Array(_TE.encode(s))
        : (s: string) => _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: string, 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: string) => 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: string) => {
    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: string) => b.replace(re_btou, cb_btou);
/**
 * polyfill version of `atob`
 */
const atobPolyfill = (asc: string) => {
    // 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 = typeof atob === 'function' ? (asc: string) => atob(_tidyB64(asc))
    : _hasBuffer ? (asc: string) => Buffer.from(asc, 'base64').toString('binary')
        : atobPolyfill;
//
const _toUint8Array = _hasBuffer
    ? (a: string) => _U8Afrom(Buffer.from(a, 'base64'))
    : (a: string) => _U8Afrom(_atob(a).split('').map(c => c.charCodeAt(0)));
/**
 * converts a Base64 string to a Uint8Array.
 */
const toUint8Array = (a: string): Uint8Array => _toUint8Array(_unURI(a));
//
const _decode = _hasBuffer
    ? (a: string) => Buffer.from(a, 'base64').toString('utf8')
    : _TD
        ? (a: string) => _TD.decode(_toUint8Array(a))
        : (a: string) => btou(_atob(a));
const _unURI = (a: string) =>
    _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: string) => _decode(_unURI(src));
/**
 * check if a value is a valid Base64 string
 * @param {String} src a value to check
  */
const isValid = (src: any) => {
    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 };