Do not report abstract methods as missing coverage

Summary

This feature requests especially concerns the term-missing report. By their nature, methods decorated with abc.abstractmethod cannot be called directly.

In the example below, pytest-cov would consider pass to be an uncovered statement.

@abc.abstractmethod
def some_abstract_method():
    pass

In this situation, it’s impossible to reach 100% coverage. I acknowledge that it’s possible to use the raise NotImplementedError approach instead of @abc.abstractmethod. However, I personally prefer to make use of abstract methods.

I would therefore greatly appreciate a feature that allows pytest-cov to omit abstract methods.

[couling]

For future readers, I’ve just realised this can easily by done by adding pass to exclude_lines in .coveragerc (described here and here):

[report]
exclude_lines =
    # Skip any pass lines such as may be used for @abstractmethod
    pass

    # Have to re-enable the standard pragma
    pragma: no cover

    # Don't complain about missing debug-only code:
    def __repr__
    if self\.debug

    # Don't complain if tests don't hit defensive assertion code:
    raise AssertionError
    raise NotImplementedError

    # Don't complain if non-runnable code isn't run:
    if 0:
    if __name__ == .__main__.:

[couling]

Another approach, which I now prefer, is to remove the pass altogether. It’s not required if the method has a doc string.

Future readers may prefer to simply document their abstract methods rather than leaving them empty. So this can be changed:

class Foo(ABC):
    @abstractmethod
    def bar(self):
        pass

To this:

class Foo(ABC):
    @abstractmethod
    def bar(self):
       """
       Do xyz to this object
       """

Some may prefer to leave pass showing red in the coverage report as a gentle reminder to document.