coverage: get coverage up

[oliver-sanders]

We should be able to hit 100% coverage for this project.

Pull requests welcome!

[MetRonnie]

stem.py is dragging down coverage. https://app.codecov.io/gh/cylc/cylc-rose

[oliver-sanders]

I think the reason for that is because the Rose Stem tests invoke rose stem via the CLI so coverage is not capturing the test usage.

cylc-rose/tests/functional/test_rose_stem.py

Lines 205 to 210 in 9b1ffd0

	def _inner_fn(rose_stem_cmd, verbosity=verbosity):
	# Run rose-stem
	run_stem = subprocess.run(
	split(rose_stem_cmd), capture_output=True,
	cwd=setup_stem_repo['workingcopy']
	)

Luckily rose stem wraps Cylc, and Cylc has a system for auto-capturing coverage for CLI calls.

$ export CYLC_COVERAGE=2
$ pytest
$ cp ../cylc-flow/<coverage-file-pattern> .
$ coverage combine

[wxtim]

The scope of the existing functional tests (Which I transferred to using Pytest but otherwise left well alone) is to check the contents of the rose-suite-cylc-install.conf for the variables set by rose-stem. This approach offers no tests for

• Workflow installation name.
• Any cases where source is not an svn repo.
• The interaction of Rose and Rose-stem CLI options (e.g. rose stem --group="Foo" -S='RUN_NAMES="Foo"')

[wxtim]

I've closed my attempt to answer this (#196), but that may contain stuff worth pulling out.