在node.js上使用bcrypt哈希密码问题

Question

I have the code below. I'm trying to hash my admin password when they get registered. The password initially is set to default via the mongoose schema. Below are my codes. But it is not hashing.

 AdminSchema.pre('save', function(next){
  let admin = this; // bind this

  if(admin.$isDefault('password')) {
        bcrypt.genSalt(12, (err, salt)=> { // generate salt and harsh password
            bcrypt.hash(admin.password, salt, (err, hash)=> {
                admin.password = hash;
                return next();
            });
        });
    }

    if(!admin.isModified('password')) {
        return next();
    }

    bcrypt.genSalt(12, (err, salt)=> { // generate salt and harsh password
        bcrypt.hash(admin.password, salt, (err, hash)=> {
            admin.password = hash;
            next();
        });
    });

});

Answer 1

It's because bcrypt method are execute asynchronously so for the first time this will be always executed

if(!admin.isModified('password')) {
  return next();
}

this should work

AdminSchema.pre('save', function(next) {
  const admin = this // bind this

  if (admin.$isDefault('password') || admin.isModified('password')) {
    bcrypt.genSalt(12, (err, salt) => { // generate salt and harsh password
      if (err) {
        return next(err);
      }
      bcrypt.hash(admin.password, salt, (err, hash) => {
        if (err) {
          return next(err);
        }
        admin.password = hash
        return next()
      })
    }) 
  } else {
    return next();
  }
})