@fanoutio/grip/build/utilities/base64.js

GRIP Interface Library

export function encodeBytesToBase64String(bytes) {
    const CHUNK_SIZE = 0x8000;
    const arr = [];
    for (let i = 0; i < bytes.length; i += CHUNK_SIZE) {
        arr.push(String.fromCharCode.apply(null, [...bytes.subarray(i, i + CHUNK_SIZE)]));
    }
    return btoa(arr.join(''));
}
export function decodeBytesFromBase64String(str) {
    // If the base64 string contains '+', but the URL was built carelessly
    // without properly URL-encoding them to %2B, then at this point they
    // may have been replaced by ' '.
    // Turn them back into pluses before decoding from base64.
    str = str.replace(/ /g, '+');
    // We also work with base64url
    str = str.replace(/_/g, '/');
    str = str.replace(/-/g, '+');
    let binary;
    try {
        binary = atob(str);
    }
    catch (ex) {
        throw new TypeError('Invalid base64 sequence', { cause: ex });
    }
    const bytes = new Uint8Array(binary.length);
    for (let i = 0; i < binary.length; i++) {
        bytes[i] = binary.charCodeAt(i);
    }
    return bytes;
}