snappymail/dev/Mime/Encoding.js

35 lines
1.3 KiB
JavaScript

const
QPDecodeParams = [/=([0-9A-F]{2})/g, (...args) => String.fromCharCode(parseInt(args[1], 16))];
export const
// https://datatracker.ietf.org/doc/html/rfc2045#section-6.8
BDecode = atob,
// unescape(encodeURIComponent()) makes the UTF-16 DOMString to an UTF-8 string
BEncode = data => btoa(unescape(encodeURIComponent(data))),
/* // Without deprecated 'unescape':
BEncode = data => btoa(encodeURIComponent(data).replace(
/%([0-9A-F]{2})/g, (match, p1) => String.fromCharCode('0x' + p1)
)),
*/
// https://datatracker.ietf.org/doc/html/rfc2045#section-6.7
QPDecode = data => data.replace(/=\r?\n/g, '').replace(...QPDecodeParams),
// https://datatracker.ietf.org/doc/html/rfc2047#section-4.1
// https://datatracker.ietf.org/doc/html/rfc2047#section-4.2
// encoded-word = "=?" charset "?" encoding "?" encoded-text "?="
decodeEncodedWords = data =>
data.replace(/=\?([^?]+)\?(B|Q)\?(.+?)\?=/g, (m, charset, encoding, text) =>
decodeText(charset, 'B' == encoding ? BDecode(text) : QPDecode(text))
)
,
decodeText = (charset, data) => {
try {
// https://developer.mozilla.org/en-US/docs/Web/API/Encoding_API/Encodings
return new TextDecoder(charset).decode(Uint8Array.from(data, c => c.charCodeAt(0)));
} catch (e) {
console.error({charset:charset,error:e});
}
};