context labelled differently

[davidszotten]

pytest --cov=test_foo --cov-context=test; coverage report --contexts=test_foo

environ identical to #900

setting dynamic_context = test_function in .coveragerc, i get context reported as
test_foo.test_foo

but without that setting, the context is reported as
test_foo.py::test_foo|run

[nedbat]

There's no single definition of what the context labels should be. The built-in "test_function" uses one style, and the pytest plugin uses another more elaborate style.

I hadn't thought much about the situation where two different mechanisms are trying to set contexts. Maybe there could be some error handling or warnings in that case?

[davidszotten]

a warning sounds reasonable to me. happy to have a first pass at a pr (warning if setting a context means overriding on already set). does coverage already have a warnings system you could point me to?

[nedbat]

There is a warnings facility, for example: https://github.com/nedbat/coveragepy/blob/cecc5ddc2d1a95223ad708a3dcc27f7a7f4d54b9/coverage/control.py#L701-L702

But off the top of my head, I'm not sure how this will work. pytest-cov sets a context by calling Coverage.switch_context, which I guess could warn if the coverage config already had a setting? We have to be careful of unintended interactions.

[davidszotten]

ah, i thought the api might have been enter/exit context

perhaps this is more of a documentation issue, e.g. recommending test runnings/plugins over dynamic_context = test_function

maybe most of my confusion is from following the alphas, and picking up the dynamic_context setting before there was support in pytest-cov

[davidszotten]

@nedbat having re-read the docs i'm happy to close this unless you think any action is needed

[nedbat]

I added a warning for this case in 16ef35f.

[nedbat]

This is now available in coverage 5.0.2