I am making a small application using node and the imap-simple and nodemailer library. I need that when I click on the download button, the email is downloaded in .eml format, which it already does, but the attached files are also downloaded in their corresponding formats.

i have this code and i try to extract attachments:

try {
    const connection = await imaps.connect(config);
    const fullSourcePath = folder.startsWith('INBOX') ? folder : `INBOX.${folder}`;

    await connection.openBox(fullSourcePath);

    const searchCriteria = [['UID', parseInt(uid)]];
    const fetchOptions = {
        bodies: ['HEADER', 'TEXT', ''],
        struct: true
    };

    const results = await connection.search(searchCriteria, fetchOptions);

    if (results.length === 0) {
        return res.status(404).send('Correo no encontrado');
    }

    const email = results[0];
    const emailBody = email.parts.filter(part => part.which === '')[0].body;

    const saveEmailPath = path.resolve(__dirname, '../../../downloads', `email-${email.attributes.uid}.eml`);

    fs.writeFile(saveEmailPath, emailBody, 'utf8', (err) => {
        if (err) {
            console.error('Error al guardar el archivo:', err);
            return res.status(500).send('Error al guardar el archivo');
        }
        console.log(`Archivo guardado en ${saveEmailPath}`);
    });

    const attachments = [];

    const findAttachments = (parts, parent) => {
        parts.forEach(part => {
            if (part.disposition && part.disposition.type.toUpperCase() === 'ATTACHMENT') {
                attachments.push({
                    filename: part.disposition.params.filename,
                    encoding: part.encoding,
                    partID: part.partID,
                    body: parent || part
                });
            } else if (part.parts) {
                findAttachments(part.parts, part);
            }
        });
    };

    findAttachments(email.parts);

    if (attachments.length > 0) {
        const attachmentPromises = attachments.map(async attachment => {
            const part = await connection.getPartData(email, attachment);
            const saveAttachmentPath = path.resolve(__dirname, '../../../downloads', attachment.filename);

            return new Promise((resolve, reject) => {
                fs.writeFile(saveAttachmentPath, part, 'base64', (err) => {
                    if (err) {
                        console.error('Error al guardar el adjunto:', err);
                        reject(err);
                    } else {
                        console.log(`Adjunto guardado en ${saveAttachmentPath}`);
                        resolve(saveAttachmentPath);
                    }
                });
            });
        });

        await Promise.all(attachmentPromises);
    }

    res.status(200).send('Correo y adjuntos descargados correctamente');
} catch (error) {
    console.error('Error descargando correo', error);
    res.status(500).send('Error descargando correo');
}

});