I'm just learning nodejs but this bug kills me inside !! My website keeps requesting twice every Post method we have. At first, I thought it was my bad in connection with mongodb but I was wrong, this happens every POST method I have on my website (except login function).

Example: My comment function

Client-side

$('.commentSubmit').click(e => {
    e.preventDefault()
    let commentContent = $('#Comment').val()
    let postId = $('#input-comment').val()
    $.ajax({
        url: '/dashboard/postComment',
        type: 'POST',
        data: {
            postId: postId,
            comment: commentContent
        }
    })
    .done(data => {
        let htmlcomment = `
            <li class="list-group-item mt-3" id="${data._id}">
                <h6 class="card-title" >${data.Owner}
                    <p class="card-text"><small class="text-muted">${data.createAt} </small></p>
                </h6>
                <h6 class="card-subtitle mb-2 text-muted"></h6>
                <p class="card-text" >${data.content} </p>
                <div class="card-footer text-muted" style="text-align: right;">
                    <button type="button" id="commentdelete" data-id="${data._id}" class="btn btn-danger btn-sm commentdelete">Delete</button>
                </div>
            </li>`

            
        $(`ul#${postId}ulul`).prepend(htmlcomment)
        document.getElementById('Comment').value = ''
    })
})

Server

router.post('/postComment', (req, res) => {
console.log('done')
req.connection.setTimeout( 1000 * 60 * 10 )
if(req.session._id) {
    if(!req.body.comment || !req.body.postId) {
        return res.render('dashboard',{errors: 'Input comment first', user: u, posts: post, comments: comment, notifs: notif})
    }
    let comment = req.body.comment
    let postId = req.body.postId
    User.findOne({_id: req.session._id})
    .then(u => {
        user = u
    })
    console.log(req.url)
    Posts.findOne({_id: postId})
    .then(p => {
        if(!p) res.send('PostID NOT Valid')
        let comment = new Comments({
            content: req.body.comment,
            Owner: user.name,
            PostId: postId
        })
        comment.save();
        return res.json(comment)
    })
} else {
    return res.redirect('/login')
}

})