Derivative with Connected Table listener not reacting to changes

[oersted]

Describe the bug

Derivatives listening to a Connected Table column fail to react to changes in any of their dependencies, even if the column that was changed was not a Connected Table column.

The logs of the Cloud Function show the following internal error:

TypeError: change.before.get(...).map is not a function
  at .updateLinks ( /workspace/src/propagates/index.js:22 )
  at undefined. ( /workspace/src/propagates/index.js:46 )
  at .Array.forEach
  at .propagate ( /workspace/src/propagates/index.js:46 )
  at undefined. ( /workspace/src/index.js:58 )
  at process.processTicksAndRejections ( node:internal/process/task_queues:95 )

I've also seen the same error with change.after.get, but less frequently.

The same Derivative does work correctly when running it manually (Evaluate cell or Evaluate All). It also works well when creating a new row (programmatically, with the requirements filled in), which makes sense it seems to be a bug with the code handling updates (change).

To Reproduce

Create a Derivative column that listens to a Connected Table column and try to manually update any column it listens to. The Derivative value will not update, no logs will be shown for that column, and the error shown above will appear in Google Cloud when looking at the Cloud Function.

Expected behavior
The Derivative should run properly whenever any Column it listens to changes.

Rowy Run version
Rowy Run v1.9.3

[oersted]

Actually, the whole table stops reacting to changes when you do this, which makes sense, it's all bundled into one function.

Inconveniently, it doesn't seem to be possible to fix the Derivative by removing the Connected Table listener, somehow the whole table becomes permanently corrupted and no reactivity works after that. The only way to get it working again seems to be to directly delete the function from Firebase and redeploy the whole thing from scratch.

[oersted]

It happens here: https://github.com/rowyio/backend/blob/b7f771dd50e23bc2a125b95b920f4152201af1eb/src/functionBuilder/functions/src/propagates/index.ts#L28
(I just realized that the problem is in the backend codebase, should I move the issue?)

const updateLinks = (
  change: functions.Change<functions.firestore.DocumentSnapshot>,
  config: { fieldName: string; trackedFields: string[] }
) => {
  const beforeDocPaths = change.before.get(config.fieldName)
    ? change.before.get(config.fieldName).map((x) => x.docPath)
    : [];

I suspect it's because with Connected Tables what actually changes are the inner docPath and snapshot fields. I'm not sure if the same issue happens when the Connected Table value is an array (multiple selection).