Ignore individual tests

[uSpike]

It would be useful for my workflow to be able to ignore specific tests while still collecting an entire directory.

For example, I have:

tests/
    test_a.py # contains test_foo(), test_bar()
    test_b.py # contains test_baz(), test_buz()

I can currently use --ignore to ignore an entire file, but not a specific test. If I want to run every test except for test_a.py::test_foo I will have a very long command line.

I propose to accept test ids with --ignore:

$ pytest tests --ignore tests/test_a.py::test_foo
$ pytest tests --ignore tests/test_a.py::test_foo[param]

Thoughts? I'd be glad to submit a PR.

[nicoddemus]

Seems useful at first sight. Feel free to submit a PR. 👍

[uSpike]

I submitted #3201 with a different implementation than I proposed. I opted to add --deselect [node_prefix] which would deselect tests during collection. I came to the conclusion that --ignore is too tied to paths to be extended for individual tests. What I wanted to implement was a way to ignore individual nodeids, and other options like -k didn't quite fit the bill.