Javascript promises not executed in order

Question

I have a problem with the following chain of promises:

Parse.Promise.as().then(function() {
        return query.first({useMasterKey: true});
      }).then(function(requestData) {
          if (!requestData) {
              return signUp(fb_ID,fb_accessToken)
          } else {
              return signIn(fb_ID,fb_accessToken)
          }
      }).then(function(userdata){
        if (userdata.success == "true") {
           response.success(userdata)
        }
        else {
          response.error(userdata)
        }
      })

var signIn = function(fb_ID,fb_accessToken) {
console.log("signin!")
var promise = new Parse.Promise();
var TokenStorage = Parse.Object.extend("tokenStorage");
var query = new Parse.Query(TokenStorage);
query.equalTo('facebookID', fb_ID);
query.ascending('createdAt');
var password;
var username;
var output = {};
var user;
// Check if this ID has previously logged in, using the master key
query.first({ useMasterKey: true }).then(function(tokenData) {

    // Update the accessToken if it is different.
    if (fb_accessToken !== tokenData.get('fb_accessToken')) {
        console.log('1')
        user = tokenData.get('user');
        user.fetch({
          success: function(data) {
              username = data.get('username')
              tokenData.set('fb_accessToken', fb_accessToken);
              /*
              password = new Buffer(24);
              _.times(24, function(i) {
                password.set(i, _.random(0, 255));
                password = password.toString('base64')
              })
              */
              password = (Date.now().toString(36) + Math.random().toString(36).substr(2, 10)).toUpperCase();

              user.setPassword(password);
              tokenData.set('password',password)
              tokenData.set('username',username)

          }         

        }).then(function(){
            tokenData.save(null, { useMasterKey: true }).then(function(tokenuser) {
                user.save();
                return Parse.User.logIn(username, password);
            }).then(function(data) {
                // Return the user object.
                output.success = true
                output.isnewuser = false
                output.username = username;
                output.password = password;
                output.fb_accessToken = fb_accessToken;
                //return Parse.Promise.as(output);
                promise.resolve(output)
                //return promise
            });
        })

    } else {
       console.log('2')
        Parse.Promise.as().then(function() {
            username = tokenData.get('username');
            password = tokenData.get('password');
        }).then(function(){
            Parse.User.logIn(username, password)
            .then(function(data) {
                // Return the user object
                output.success = true
                output.isnewuser = false
                output.username = username;
                output.password = password;
                output.fb_accessToken = fb_accessToken;
                console.log('oo'+JSON.stringify(output))
                //return Parse.Promise.as(output);
                promise.resolve(output)

            });
        })

    }
})
return promise
}

var signUp = function(fb_ID,fb_accessToken) {
console.log("signup")
ExtendFacebookAccessToken(fb_accessToken).then(function(new_fb_accessToken){
        var TokenStorage = Parse.Object.extend("tokenStorage");
        var restrictedAcl = new Parse.ACL();
        restrictedAcl.setPublicReadAccess(false);
        restrictedAcl.setPublicWriteAccess(false);
        var user = new Parse.User();

        // Generate a random username and password.
        /*var username = new Buffer(24);
        var password = new Buffer(24);
        _.times(24, function(i) {
          username.set(i, _.random(0, 255));
          password.set(i, _.random(0, 255));
        });
        */
        var username = (Date.now().toString(36) + Math.random().toString(36).substr(2, 10)).toUpperCase();
        var password = (Date.now().toString(36) + Math.random().toString(36).substr(2, 10)).toUpperCase();

        user.set("username", username.toString('base64'));
        user.set("password", password.toString('base64'));
        // Sign up the new User
        return user.signUp().then(function(user) {
          console.log('user'+JSON.stringify(user))
          // create a new TokenStorage object to store the user+GitHub association.
          var ts = new TokenStorage();
          ts.set('facebookID', fb_ID);
          ts.set('fb_accessToken', new_fb_accessToken);
          ts.set('username',username)
          ts.set('password',password)
          ts.set('user', user);

          ts.setACL(restrictedAcl);
          // Use the master key because TokenStorage objects should be protected.
          return ts.save(null, { useMasterKey: true });
        }).then(function(tokenStorage) {
            var output
            var promise = new Parse.Promise();
            output.username = username;
            output.password = password;
            output.process = "signup";
            output.fb_accessToken = new_fb_accessToken;
            output.success = true;
            output.isnewuser = true
            promise.resolve(output);
            return promise
        });
    })   
}

both SignUp and SignIn return a promise but the problem is that the last then ( 'then(function(userdata)...') is executed before the SignUp and SignIn return 'userdata'. I thought that the return in front of the SignUp or SignIn functions will be sufficient to force the last promise to wait for the userdata but it is not. Any idea?

What are SignUp and SignIn ? It is not obvious that they 'return a promise'. — Estus Flask, Sep 20 '16 at 12:34
if `both SignUp and SignIn return a promise` then your code looks like it should definitely do what you think it should - you have confirmed that those functions actually return a promise? — Jaromanda X, Sep 20 '16 at 12:37
@estus - it's also not obvious that query.first returns a promise — Jaromanda X, Sep 20 '16 at 12:38
`user.fetch` does not appear to use promises. Also, avoid the [Promise constructor antipattern](http://stackoverflow.com/q/23803743/1048572)! — Bergi, Sep 20 '16 at 12:56

score 0 · Answer 1 · answered Sep 24 '16 at 01:43

Your signup method is not returning a promise. Instead you are most likely getting undefined which is resolving immediately

Change:

var signUp = function(fb_ID,fb_accessToken) {
console.log("signup")
ExtendFacebookAccessToken(fb_accessToken).then(function(new_fb_accessToken)

To:

var signUp = function(fb_ID,fb_accessToken) {
console.log("signup")
return ExtendFacebookAccessToken(fb_accessToken).then(function(new_fb_accessToken)

And please, please, indent your code :(

Javascript promises not executed in order

1 Answers1