On issue boards sidebar, assignee popover doesn't show data

Summary

On the issue boards sidebar, when hovering an assignee, the popover shows skeleton for data loading that never disappears. This is caused by the wrong URL for the API call (we pass GraphQL GID there instead of assignee user ID, like we do on issue sidebar).

Boards sidebar Issue sidebar
Screenshot_2022-05-23_at_11.00.28 Screenshot_2022-05-23_at_11.00.12

Here is a screenshot of the wrong URL:

Screenshot_2022-05-23_at_11.00.50

Steps to reproduce

  1. Open issue boards
  2. Click on any card that has an assignee
  3. On the sidebar, hover the assignee

You will see a skeleton loader and on Devtools -> Network there is a 404 error

Example Project

This bug is reproducible on GitLab.com

What is the current bug behavior?

No data is loaded in the assignee popover

What is the expected correct behavior?

The assignee popover should be populated with assignee details

Possible fixes

We should pass the correct ID to the popover