add tests for wp_list_filter

wpListeFilter.php claimed to test wp_list_filter but had no tests for it so I have added them

Trac ticket: https://core.trac.wordpress.org/ticket/53987

[pbearne]

removed duplicate code in https://core.trac.wordpress.org/ticket/53988

[SergeyBiryukov]

Thanks for the PR!

Just noting there also some existing tests for wp_list_filter() in tests/functions/wpListUtil.php.

It looks like:

• wpListFilter.php has tests for wp_filter_object_list() and wp_list_pluck().
• wpListUtil.php has tests for wp_list_pluck(), wp_list_filter(), wp_list_sort(), and the WP_List_Util class.

This could probably use some reorganization for clarity and to make sure the tests are not duplicated.

[SergeyBiryukov]

In 51663:

Tests: Move wp_list_pluck() tests to their own file.

The tests were partially duplicated in two separate files.

Follow-up to [431/tests], [28900], [38928], [42527].

See #53363, #53987.

[SergeyBiryukov]

In 51664:

Tests: Remove duplicate wp_list_pluck() tests.

The tests were partially duplicated in two separate files, and are now located in their own file.

Follow-up to [431/tests], [28900], [38928], [42527], [51663].

See #53363, #53987.

[SergeyBiryukov]

In 51665:

Tests: Rename the test file and class for wp_filter_object_list() tests.

This matches the name of the function being tested.

Follow-up to [410/tests], [51663], [51664].

See #53363, #53987.

[SergeyBiryukov]

In 51666:

Tests: Move wp_list_filter() tests to their own file.

This matches the name of the function being tested.

Follow-up to [38928], [51663-51665].

See #53363, #53987.

[SergeyBiryukov]

In 51667:

Tests: Move wp_list_sort() tests to their own file.

This matches the name of the function being tested.

Follow-up to [38928], [51663-51666].

See #53363, #53987.

[SergeyBiryukov]

In 51668:

Coding Standards: Add missing visibility keywords for wp_filter_object_list() and wp_list_pluck() tests.

Follow-up to [51663-51667].

Props pbearne.
See #53363, #53987.

[SergeyBiryukov]

What's left here:

• See if wp_list_pluck() tests can be simplified further. Some use older fixtures and some use a data provider, so we could review the older fixtures and move them to the data provider too if it does not cover those cases yet.
• See if any additional tests for wp_list_filter() are necessary and not already covered by the data provider.

Good work here @pbearne. Can you rebase with master to resolve the merge conflict. Then it should be ready.

[pbearne]

My patch is not now needed closing pull request

the updated test replaces this patch
closing

[hellofromTonya]

Today is 5.9 Feature Freeze. I'll punt this to Future Release (as 6.0 isn't
available yet for selection).

Test and build tool changes are allowed after feature freeze up until RC. If someone is able to work on this before then, it can always be moved back.