Why is the promise response empty?

Question

JavaScript

Good evening. Please tell me. I'm trying to get information from the server using a promise, but the answers are empty.
Customer:

const sendMenu = ms => {
        return new Promise(r => setTimeout(() => r(), ms))
      }

      const url = 'http://localhost:3000/menu'

      function fetchTodos() {
        console.log('Fetch todo started...')
        return sendMenu(2000).then(() => {
          return fetch(url)
        })
        .then(response => response)
      }

      fetchTodos()
        .then(data => {
          console.log('Data: ',data)
        })
        .catch(e => console.error(e))

Server:

app.post('/menu', (req,res) => {

    let viewmenu;

    connection.query('SELECT * FROM menu', (err, result) => {
        if(err) {
          console.error(err);
          return;
        }

        const index = result.reduce((acc, row) => ({...acc, [row.id]: row}), {});
          var menu = [];
          for(const row of result) {
              if(row.parent_id === 0) {
                menu.push(row);
                continue;
              }
              const parent = index[row.parent_id];
              if(!parent) {
                console.warn(`Undefined parent with id ${row.parent_id}`);
                continue;
              }
              if(!parent.children) {
                parent.children = [];
              }
              parent.children.push(row);
              
        }

        viewmenu = menu;

    });

    const sendMenu = ms => {
      return new Promise(r => setTimeout(() => r(), ms))
    }

    sendMenu(200).then(() => res.send(viewmenu))

})

Answer 1

Because the answer, the server, goes first, and then the data is received from the database. Move the response code inside the callback for getting data from the database.