오류 이유

app.post('/delete_process', (req, res)=>{
    var post = req.body;
    var id = post.id;
    var filteredId = path.parse(id).base;
    fs.unlink(`data/${filteredId}`, function(error){
      res.redirect('/');
    })
});

app.get('/topic/:pageID', (request, response,next)=>{
  var filteredId = path.parse(request.params.pageID).base;
  fs.readFile(`data/${filteredId}`, 'utf8', function(err, description){
    if(err){
      next(err);
    } else{
      var title = request.params.pageID;
      var sanitizedTitle = sanitizeHtml(title);
      var sanitizedDescription = sanitizeHtml(description, {
      allowedTags:['h1']
      });
      var list = template.list(request.list);
      var html = template.HTML(sanitizedTitle, list,
        `<h2>${sanitizedTitle}</h2>${sanitizedDescription}`,
        ` <a href="/topic/create">create</a>
        <a href="/topic/update/${sanitizedTitle}">update</a>
          <form action="/delete_process" method="post">
            <input type="hidden" name="id" value="${sanitizedTitle}">
            <input type="submit" value="delete">
          </form>`
      );
      response.send(html);
    }
  });
});

이렇게 했을 때는 정상적으로 삭제가 되는데 왜

app.post('/topic/delete_process', (req, res)=>{     var post = req.body;     var id = post.id;     var filteredId = path.parse(id).base;     fs.unlinkdata/${filteredId}, function(error){       res.redirect('/');     }) }); app.get('/topic/:pageID', (request, response,next)=>{   var filteredId = path.parse(request.params.pageID).base;   fs.readFiledata/${filteredId}, 'utf8', function(err, description){     if(err){       next(err);     } else{       var title = request.params.pageID;       var sanitizedTitle = sanitizeHtml(title);       var sanitizedDescription = sanitizeHtml(description, {       allowedTags:['h1']       });       var list = template.list(request.list);       var html = template.HTML(sanitizedTitle, list,         <h2>${sanitizedTitle}</h2>${sanitizedDescription},         <a href="/topic/create">create</a>         <a href="/topic/update/${sanitizedTitle}">update</a>           <form action="/topic/delete_process" method="post">             <input type="hidden" name="id" value="${sanitizedTitle}">             <input type="submit" value="delete">           </form>       );       response.send(html);     } 이렇게 작성햇을때는 왜 안되는지 이유를 너무 모르겠습니다.