The skipIfDBFeature decorators and its variants should respect their defined wrapped order and test case inheritance.

[Simon Charette]

The database features test skipping decorators do not respect the order in which they are wrapped or inherited and end up masking the original reason that resulted in skipping the test.

For example given the following test case classes:

@skipIfDbFeature('available')
@skipUnlessDbFeature('missing')
class Foo(TestCase):
   def test_foo(self):
        pass

@skipUnlessDbFeature('also-missing')
class Bar(Foo):
    def test_bar(self):
        pass

The Foo.test_foo method would be skipped with the following reason: 'Database has feature(s) available' and the Bar.test_bar method would be skipped with 'Database doesn't support feature(s): also-missing' when both should be skipped with 'Database doesn't support feature(s): missing'.

This is an issue I discovered while working on 32c0d823e5316aa7d616a69996919b62748368cc where I noticed JSONB tests were skipped with the 'Database doesn't support feature(s): has_jsonb_datatype' instead of the expected 'PostgreSQL specific tests' when running tests using the SQLite backend.

[Simon Charette]

​PR

[Simon Charette <charette.s@…>]

In 18c72d59:

Fixed #27214 -- Made skip db features decorators respect wrapping order and inheritance.