Incorrect due dates on Canvas assignments

[TreesClouds]

Assignments synced from Canvas seem to take on incorrect due dates after some amount of time - rather than maintaining the original due date, the due date for the entire assignment in Flextensions becomes the extended due date of a random student. This has happened to all Canvas-based assignments in CS 61C so far, and no staff had manually changed due dates after the assignment's initial creation.

This issue likely stems from the fact that the Canvas API's due date field (which is used by Flextensions) changes, seemingly at random.

An example of this from CS 61C is given below. The due date for the assignment should be February 5th, but this date was changed to the 9th in Flextensions, a due date only one student should have.

A subset of due dates in Canvas:

The due date in Flextensions:

The due date given by the Canvas API:

[TreesClouds]

I've done some more research on this issue to try and figure out the root cause.

First, the due_at field given by the Canvas API seems to be wrong for teacher accounts when there are overrides (see instructure/canvas-lms#1547). Flextensions seems to try to account for this by manually determining the base date using the all_dates query if it can (see here) and overriding the default due_at parameter (see here).

However, the Canvas API imposes a limit on the number of dates that can be viewed with this method (see here). Once this limit, currently set to 25, is reached, no dates will be shown at all and the workaround breaks.

So essentially, after 25 extensions have been approved with Flextensions, there's a chance the assignment's overall due date will change...

[TreesClouds]

I found an API endpoint that could help solve this issue: link

From my limited testing on CS 61C assignments, the due_at field given by this endpoint is the correct due date.

With the base assignments endpoint:

With the date_details endpoint: