Sorting preference functionality has been extracted
from `IssuableCollections` to a new `SortingPreference`
concern in order to reuse this functionality in projects
(and groups in the future).
In order to let users' sorting preferences transfer between devices, we
save the preference for issues and MRs (one preference for issues, one
for MRs) in the backend inside the UserPreference object
By extracting a new `filter_items` method, we can override that in the
IssuesFinder and MergeRequestsFinder separately, so we don't need checks that
the model is the correct one, because we can just use the class we're in to know
that.
We can do the same for the VALID_PARAMS constant, by making it a class method.
This changes the issue and MR index pages so the pagination system
re-uses the output of the COUNT(*) query used to calculate the number of
rows per state (opened, closed, etc). This removes the need for an
additional COUNT(*) on both pages.
GitLab Bot