I tried the code from uncompress.js. But I do not understand why the js need to load the format and after that reactive the button. Can anyone simplelize the code so that I can use it locally without blob, promise or async. I just need to test compresd a file with browser.

loadArchiveFormats(['rar', 'zip', 'tar'], function() {
    fileInput.onchange = function() {
        // Just return if there is no file selected
        if (fileInput.files.length === 0) {
            entryList.innerHTML = 'No file selected';
            return;
        }
        // Get the selected file
        let file = fileInput.files[0];

        let password = filePassword.value; 
    // Open the file as an archive
    archiveOpenFile(file, password, function(archive, err) {
        if (archive) {
            console.info('Uncompressing ' + archive.archive_type + ' ...');
            entryList.innerHTML = '';
            onArchiveLoaded(archive);
        } else {
            entryList.innerHTML = '<span style="color: red">' + err + '</span>';
        }
    });
};

fileInput.disabled = false;

}); '''