Exception in changedobserveChanges callback: Error: Cannot read property 'documents' of undefined

[lc3t35]

Hi, I have this strange error (meteor 1.8, tunguska-reactive-aggregate 1.3.10)

2022-10-30 18:29:33+01:00 Exception in changedobserveChanges callback: Error: Cannot read property 'documents' of undefined
cr7ta
2022-10-30 18:29:33+01:00 at update (packages/tunguska:reactive-aggregate/aggregate.js:282:13)
cr7ta
2022-10-30 18:29:33+01:00 at debounce (packages/tunguska:reactive-aggregate/aggregate.js:301:7)
cr7ta
2022-10-30 18:29:33+01:00 at changed (packages/tunguska:reactive-aggregate/aggregate.js:323:9)
cr7ta
2022-10-30 18:29:33+01:00 at runWithEnvironment (packages/meteor.js:1347:24)
cr7ta
2022-10-30 18:29:33+01:00 at packages/meteor.js:1360:14
cr7ta
2022-10-30 18:29:33+01:00 at packages/mongo/observe_multiplex.js:178:30
cr7ta
2022-10-30 18:29:33+01:00 at Array.forEach (<anonymous>)
cr7ta
2022-10-30 18:29:33+01:00 at Function._.each._.forEach (packages/underscore.js:139:11)
cr7ta
2022-10-30 18:29:33+01:00 at Object.task (packages/mongo/observe_multiplex.js:172:9)
cr7ta
2022-10-30 18:29:33+01:00 at Meteor._SynchronousQueue.SQp._run (packages/meteor.js:924:16)
cr7ta
2022-10-30 18:29:33+01:00 at packages/meteor.js:901:12
cr7ta
2022-10-30 18:29:34+01:00Exception in setTimeout callback: Error: Cannot read property 'documents' of undefined
cr7ta
2022-10-30 18:29:34+01:00 at update (packages/tunguska:reactive-aggregate/aggregate.js:282:13)
cr7ta
2022-10-30 18:29:34+01:00 at packages/tunguska:reactive-aggregate/aggregate.js:294:7
cr7ta
2022-10-30 18:29:34+01:00 at Meteor.EnvironmentVariable.EVp.withValue (packages/meteor.js:1259:12)
cr7ta
2022-10-30 18:29:34+01:00 at packages/meteor.js:557:25
cr7ta
2022-10-30 18:29:34+01:00 at runWithEnvironment (packages/meteor.js:1347:24)

[robfallows]

There's only one place in the code where that can appear:

tunguska-reactive-aggregate/aggregate.js

Line 254 in 65788b2

const previousFields = [...sub._session.collectionViews.get(localOptions.clientCollection).documents.get(doc_id).dataByKey.keys()];

Is it possible there's no client collection defined?

[lc3t35]

FYI, I've updated existing meteor 2.2 to 2.8 and latest tunguska-reactive-aggregate 1.3.10 - you can edit the title of Readme still at 1.3.9)
clientCollection is optional ("defaults to the same name as the original collection"), so it is not defined in every aggregates in my code.
It should be by default :

clientCollection: collection._name,

let's check if sub._session.collectionViews.get(localOptions.clientCollection) exist before getting .documents of it ? if not log : localOptions.clientCollection and keys of sub._session.collectionViews :

if ( sub._session.collectionViews.get(localOptions.clientCollection) === undefined) {
   function logMapKeys(value, key) { console.log(`${key}`);}
   console.log(
      '#73 localOptions.clientCollection : ', localOptions.clientCollection, sub._session.collectionViews.forEach(logMapKeys)
   );
} else {
...
}

Deployed to get more information ...

[lc3t35]

here is the log :

2022-11-02 10:17:18+01:00Settings updated for user : v...L
2022-11-02 14:55:35+01:00Settings updated for user : v...L
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : pensees undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : pensees undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : pensees undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : pensees undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : pensees undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : pensees undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : pensees undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : pensees undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : pensees undefined
2022-11-02 16:10:57+01:00#73 localOptions.clientCollection : pensees undefined
2022-11-02 16:10:58+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:58+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:58+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:58+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:58+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:58+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:58+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:58+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:58+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:10:58+01:00#73 localOptions.clientCollection : moments undefined
2022-11-02 16:12:21+01:00Settings updated for user : J...h
2022-11-02 16:17:49+01:00Settings updated for user : v...L

so we are losing sub._session.collectionViews ....

[robfallows]

Hmm. I've just checked the Meteor code - the use of _ names on properties is always risky. However, it's still present.

What's your code for defining the publication?

[lc3t35]

the problem is not at collection._name (displayed in log as "moments", "pensees") but that sub._session.collectionViews is undefined

code :

Meteor.publish(
  'moments.followedById',
  function (userId, limit = 5) {
    ....
    ReactiveAggregate(
      this,
      Moments,
      [ .... ],
      {
        noAutomaticObserver: true,
        debounceDelay: 100,
        observers: [
          Moments.find({}),
          Contacts.find({}),
          Contacts.find({
            $or: [
              { $where: 'this.followedBy.length >= 0' },
              { $where: 'this.following.length >= 0' },
              { $where: 'this.blocked.length >= 0' },
            ],
          }),
          Meteor.users.find({}),
        ],
      }

[robfallows]

Agreed, but there was a possibility that this was not valid (if you'd used => instead of function()).

[lc3t35]

Thank you Rob for your time, if the user is disconnected for a few seconds, would this be the cause of the issue ?

[robfallows]

If you enable the debug option, do you get a notification about the observers being stopped?

tunguska-reactive-aggregate/aggregate.js

Lines 335 to 336 in 65788b2

	sub.onStop(() => {
	if (options.debug) console.log(`Reactive-Aggregate: stopping observers`)

[georgekovach]

Hello guys,

I've created a single-line PR which fixed this issue for me.