Replacing Callbacks with Promises

Here is the code which exhibits the callback pattern for dialing with async work:

function getUser(id, callback) {
  console.log("Reading a user from a database...");
  setTimeout(() => {
    console.log("Received user data...");
    callback({ "ID": id, "Account number": "58721094531267" });
  }, 2000);
}

console.log("listening for events");
getUser(1, (user) => console.log(user));
console.log("still listening for events!");

We are going to replace the callback pattern with the Promise pattern. As a first step, we must update our async function getUser to return a Promise.

function getUser(id) {
  console.log(`Reading a user from a database!`);

  const promise = new Promise((resolve, reject) => {
    const success = true; 
    setTimeout(() => {
      if (success) {
        console.log(`Recieved user data!`);
        resolve({ "ID": id, "Account number": "58721094531267" });
      } else {
        reject(new Error("Could not read the user data!"));
      }
    }, 2000);
  })

  return promise;
}

Exercise Update how getUser is employed. (Hint: you must consume a Promise).

function getUser(id) {
  console.log(`Reading a user from a database!`);

  const promise = new Promise((resolve, reject) => {
    const success = true; 
    setTimeout(() => {
      if (success) {
        console.log(`Recieved user data!`);
        resolve({ "ID": id, "Account number": "58721094531267" });
      } else {
        reject(new Error("Could not read the user data!"));
      }
    }, 2000);
  })

  return promise;
}

console.log("listening for events");
getUser(1, (user) => console.log(user)); // TODO update me!
console.log("still listening for events!");

console.log("listening for events!");
getUser(1)
  .then(user => console.log(user))
  .catch(err => console.log(err.message));
console.log("still listening for events!");