[1.8.3] onLogin handler fired twice

[AndyCC25]

Updating the version from 1.8.1 to 1.8.3, notice that a part of the code that relies in a callback to Accounts.onLogin() method from it’s being called twice. reference to https://forums.meteor.com/t/onlogin-handler-fired-twice-meteor-1-8-3/51224.

• Version: Meteor: 1.8.3
• Last version without the issue: Meteor 1.8.1
• OS: Ubuntu 14.04
• Expected Behavior: onLogin callback should run once
• Actual Behavior: onLogin callback runs twice
• Reproduction: run the reproduction project and notice that the onLogin callback fire twice, can check by a simple console.log(). Project: https://github.com/AndyCC25/meteor-login-bug

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[afrokick]

not stale

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[brendonlamb]

Still not state in Meteor 1.10.2 - just upgraded, same issue.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[AndyCC25]

Also I notice that still happens the two fire

[AndyCC25]

a WA could use a once() function from underscore

[santiagopuentep]

Same issue in Meteor 1.11.

[namenotrequired]

It seems like there's a few separate bugs going on here.

On initial login

A seemingly old bug in accounts-ui-unstyled/login_buttons_dropdown.js: if I click on the login button, I login once. But if I submit the form by hitting enter, I trigger two separate event listeners that both try to log me in, and we end up calling onLogin twice.

I made a PR to fix it (and a related bug): #11173

On load when already logged in

On refresh, it is called once by loggedInAndDataReadyCallback, as normal, and once by _startupCallback which was introduced in this PR that was included in Meteor 1.8.2

I assume this is the bug that didn't happen on 1.8.1. I haven't looked into it further yet.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[santiagopuentep]

Still happening on Meteor 1.11.

[filipenevola]

This should be fixed on Meteor 1.12

[jasongrishkoff]

Was optimistic v1.12 would solve my double login issue, but I guess not.

Accounts.onLogin still fires twice for me when I refresh the page (if previous logged in). If I load the page logged out, then log in, onLogin only fires once. Specifically, this happens when onLogin passes {type: "resume"}.

I wonder if it has something to do with this part of accounts-base:

  // https://github.com/meteor/meteor/blob/devel/packages/accounts-base/accounts_client.js
  // _startupCallback executes on onLogin callbacks
  // at registration time if already logged in
  // this can happen when new AccountsClient is created
  // before callbacks are registered see #10157
  _startupCallback(callback) {
    // Are we already logged in?
    if (this.connection._userId) {
      // If already logged in before handler is registered, it's safe to
      // assume type is a 'resume', so we execute the callback at the end
      // of the queue so that Meteor.startup can complete before any
      // embedded onLogin callbacks would execute.
      Meteor.setTimeout(() => callback({ type: 'resume' }), 0);
    }
  }

I can tell that the startup finishes before Accounts.onLogin fires, so not entirely sure how that works.

[filipenevola]

@namenotrequired maybe @jasongrishkoff's case is a different one?

[jamesloper]

Same behavior here as @jasongriskoff - When I log in with my React form, it fires once. When using a resume token it's firing twice in rapid succession. It seems like a race condition to me. The time between the two logins is median 70 to 80 milliseconds but as high as 400 millis. I also tried removing all onLogin callbacks and just putting in a single one as a test.

Would it be possible to reopen this issue?

[jamesloper]

This bug might be simpler to find than we thought. It looks like the first time it fires, Meteor.user() is undefined and the second time, it is the actual user document. Meteor.userId() is set both times. So it seems the meteor internals are emitting before and after the default null sub is ready.

[santiagopuentep]

@jamesloper this is exactly the problem I'm having, it fires twice, but the first time Meteor.user() is not available; the second time it its.

[StorytellerCZ]

This issue persists as per #11446, which was closed as a duplicate of this one.

[brucejo75]

@jasongrishkoff & @namenotrequired you were right on target.
PR #11785 should address it.

Sorry I just noticed this issue. To speed things up next time:

• Referencing a PR or other issue does not notify the author
• In a case like this it may have been addressed quicker if you had mentioned the author of the offending PR (e.g. @brucejo75)

Sorry I goofed it & sorry I did not see this earlier! Simple fix.

[paulincai]

@filipenevola this is still going on in 2.5.3

[filipenevola]

Should be fixed in Meteor 2.5.5 coming out soon.