python/aqmp: Add Coverage.py support

I'm not exposing this via the Makefile help, it's not likely to be
useful to passersby. Switch the avocado runner to the 'legacy' runner
for now, as the new runner seems to obscure coverage reports, again.

Usage is to enter your venv of choice and then:
`make check-coverage && xdg-open htmlcov/index.html`.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-id: 20210915162955.333025-28-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

python/.gitignore

@@ -15,3 +15,8 @@ qemu.egg-info/
 .venv/
 .tox/
 .dev-venv/
+
+# Coverage.py reports
+.coverage
+.coverage.*
+htmlcov/

python/Makefile

@@ -92,6 +92,13 @@ check:
 check-tox:
 	@tox $(QEMU_TOX_EXTRA_ARGS)
 
+.PHONY: check-coverage
+check-coverage:
+	@coverage run -m avocado --config avocado.cfg run tests/*.py
+	@coverage combine
+	@coverage html
+	@coverage report
+
 .PHONY: clean
 clean:
 	python3 setup.py clean --all
@@ -100,3 +107,5 @@ clean:
 .PHONY: distclean
 distclean: clean
 	rm -rf qemu.egg-info/ .venv/ .tox/ $(QEMU_VENV_DIR) dist/
+	rm -f .coverage .coverage.*
+	rm -rf htmlcov/

python/avocado.cfg

@@ -1,3 +1,6 @@
+[run]
+test_runner = runner
+
 [simpletests]
 # Don't show stdout/stderr in the test *summary*
 status.failure_fields = ['status']

python/setup.cfg

@@ -140,3 +140,13 @@ deps =
     .[fuse]  # Workaround to trigger tox venv rebuild
 commands =
     make check
+
+# Coverage.py [https://coverage.readthedocs.io/en/latest/] is a tool for
+# measuring code coverage of Python programs. It monitors your program,
+# noting which parts of the code have been executed, then analyzes the
+# source to identify code that could have been executed but was not.
+
+[coverage:run]
+concurrency = multiprocessing
+source = qemu/
+parallel = true