Trying to hash a password using bcrypt inside an async function

Question

Following on from this question.

I feel like I'm almost there, but my incomplete understanding of async is preventing me from solving this. I'm basically trying to just hash a password using bcrypt and have decided to seperate out the hashPassword function so that I can potentially use it in other parts of the app.

hashedPassword keeps returning undefined though...

userSchema.pre('save', async function (next) {    let user = this   const password = user.password;    const hashedPassword = await hashPassword(user);   user.password = hashedPassword    next()  })  async function hashPassword (user) {    const password = user.password   const saltRounds = 10;    const hashedPassword = await bcrypt.hash(password, saltRounds, function(err, hash) {      if (err) {       return err;     }      return hash    });    return hashedPassword  } 

Answer 1

await dosent wait for bcrypt.hash because bcrypt.hash does not return a promise. Use the following method, which wraps bcrypt in a promise in order to use await.

async function hashPassword (user) {    const password = user.password   const saltRounds = 10;    const hashedPassword = await new Promise((resolve, reject) => {     bcrypt.hash(password, saltRounds, function(err, hash) {       if (err) reject(err)       resolve(hash)     });   })    return hashedPassword } 

Update:-

The library has added code to return a promise which will make the use of async/await possible, which was not available earlier. the new way of usage would be as follows.

const hashedPassword = await bcrypt.hash(password, saltRounds)