Add tests for get_post_type_labels()

[swissspidy]

Working on #26511 and #29783, I'd thought it would be a good idea to have tests covering get_post_type_labels() in case we'd have to do some refactoring.

[swissspidy]

IIRC from #38218, some assertions need to be tweaked, but otherwise nothing speaks against adding tests.

[swissspidy]

In 40635:

Posts, Post Types: Add initial tests for get_post_type_labels().

See #38218.
Fixes #38157.

[swissspidy]

In 42490:

Posts, Post Types: Add tests for get_post_type_labels().

These were accidentally omitted in [38157].

See #38157.

[birgire]

Hi @swissspidy

I just recalled you comment here on 42044#comment:1 regarding the cleanup, when I skimmed over these methods in [42490] :

test_labels_should_be_added_when_registering_a_post_type()
test_label_should_be_derived_from_labels_when_registering_a_post_type()
test_should_fall_back_on_defaults_when_filtered_labels_do_not_contain_the_keys

The first one calls unregister_post_type( 'foo' ) before the assertions but the latter two do it afterwards.

Would the note be relevant in this case?

[swissspidy]

@birgire Good call! I haven't closely looked at the tests, but yes, that should generally be avoided. I'll try to have a look at it soon. Perhaps even by going through _all_ tests to improve this.