This work was done in collaboration with Liam!

This addresses a problem Teacher Tools has run into occasionally on our progress page, both in the "legacy" and V2 views.

In legacy view, this would show up in some sections when toggling over to level view. While scrolling down the page would suddenly break and show the below error.

In V2, the progress view would just constantly show "loading" skeleton as the data would constantly load and re-load.

The "fix" was always to add or remove one student from the section. This would fix the errors, but was not the ideal user experience

We were able to re-create this issue locally. It seems like the issue is able to be re-created if you put 60 students all with the same name in the section AND give progress to one of the students. We suspect that this issue was revealing itself in production when a section:

1. Has more than 20 students - probably more than 40 (20 students is considered a "page" in our system)
2. Two students have the same "name" and those two students straddled a "page" - say that they were students 20 and 21.

The fix here is to modify how we "deduplicate" students so we rely solely on ID.

Links

Jira ticket
Thread

• Jira:

Testing story

Deployment strategy

• Deploy and revisit the above zen desk ticket to see if the section works now.