[PATCH v2 2/4] python: replace avocado tests with pytest

[John Snow <jsnow@redhat.com>]

Following suit with the rest of this repository, drop avocado and
replace it with the Python standard "pytest" package.

In this case, we do not truly need pytest as all we are using it for is
running other python processes formerly launched by shell scripts, but
this matches how the standalone python-qemu-qmp package does things,
which keeps things simple on my end.

(pytest version chosen based off of Debian 11's package version as queried by
repology; under the assumption that this is the likely the oldest
version we currently leverage in testing.)

Signed-off-by: John Snow <jsnow@redhat.com>
---
 python/Makefile          |  4 +-
 python/setup.cfg         |  1 +
 python/tests/linters.py  | 89 ++++++++++++++++++++++++++++++++++++++++
 python/tests/minreqs.txt |  1 +
 4 files changed, 93 insertions(+), 2 deletions(-)
 create mode 100644 python/tests/linters.py

diff --git a/python/Makefile b/python/Makefile
index b6c9cd1bce2..42994d39618 100644
--- a/python/Makefile
+++ b/python/Makefile
@@ -105,7 +105,7 @@ develop:
 
 .PHONY: check
 check:
-	@avocado --config avocado.cfg run tests/
+	@pytest -v tests/*.py
 
 .PHONY: check-tox
 check-tox:
@@ -113,7 +113,7 @@ check-tox:
 
 .PHONY: check-coverage
 check-coverage:
-	@coverage run -m avocado --config avocado.cfg run tests/*.py
+	@coverage run -m pytest -v tests/*.py
 	@coverage combine
 	@coverage html
 	@coverage report
diff --git a/python/setup.cfg b/python/setup.cfg
index c46a95f8d41..03344526730 100644
--- a/python/setup.cfg
+++ b/python/setup.cfg
@@ -43,6 +43,7 @@ devel =
     mypy >= 1.4.0
     pylint >= 2.17.3
     pylint != 3.2.4; python_version<"3.9"
+    pytest >= 6.0.2
     tox >= 3.18.0
     sphinx >= 3.4.3
 
diff --git a/python/tests/linters.py b/python/tests/linters.py
new file mode 100644
index 00000000000..28556c09910
--- /dev/null
+++ b/python/tests/linters.py
@@ -0,0 +1,89 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+import os
+import subprocess
+import sys
+
+
+def pyrun(*args):
+    subprocess.run((sys.executable, *args), check=True)
+
+
+class TestLinters:
+
+    def test_flake8_pkg(self):
+        pyrun("-m", "flake8", "qemu/")
+
+    def test_flake8_scripts(self):
+        pyrun("-m", "flake8", "scripts/")
+
+    def test_flake8_qapi(self):
+        pyrun("-m", "flake8",
+              "../scripts/qapi/",
+              "../docs/sphinx/qapidoc.py",
+              "../docs/sphinx/qapi_domain.py")
+
+    def test_isort_pkg(self):
+        pyrun("-m", "isort", "-c", "qemu/")
+
+    def test_isort_scripts(self):
+        pyrun("-m", "isort", "-c", "scripts/")
+
+    def test_isort_qapi(self):
+        pyrun("-m", "isort", "--sp", ".", "-c", "../scripts/qapi/")
+
+    def test_isort_qapi_sphinx(self):
+        # Force isort to recognize 'compat' as a local module and not
+        # third-party
+        pyrun("-m", "isort", "--sp", ".", "-c", "-p", "compat",
+              "../docs/sphinx/qapi_domain.py",
+              "../docs/sphinx/qapidoc.py")
+
+    def test_mypy_pkg(self):
+        pyrun("-m", "mypy", "-p", "qemu")
+
+    def test_mypy_scripts(self):
+        pyrun("-m", "mypy", "scripts/")
+
+    def test_mypy_qapi(self):
+        pyrun("-m", "mypy", "../scripts/qapi")
+
+    def test_mypy_iotests(self):
+        cwd = os.getcwd()
+        try:
+            os.chdir("../tests/qemu-iotests/")
+            pyrun("-m", "linters", "--mypy")
+        finally:
+            os.chdir(cwd)
+
+    # Setuptools v60 introduced the SETUPTOOLS_USE_DISTUTILS=stdlib
+    # workaround; stdlib distutils was fully removed in Python
+    # 3.12+. Once we are on >=3.12+ exclusively, this workaround can be
+    # dropped safely. Until then, it is needed for some versions on
+    # Fedora/Debian distributions which relied upon distro-patched
+    # setuptools present in CPython, but not within setuptools itself.
+
+    def test_pylint_pkg(self):
+        os.environ['SETUPTOOLS_USE_DISTUTILS'] = 'stdlib'
+        pyrun("-m", "pylint", "qemu/")
+
+    def test_pylint_scripts(self):
+        os.environ['SETUPTOOLS_USE_DISTUTILS'] = 'stdlib'
+        pyrun("-m", "pylint", "qemu/")
+
+    def test_pylint_qapi(self):
+        os.environ['SETUPTOOLS_USE_DISTUTILS'] = 'stdlib'
+        pyrun("-m", "pylint",
+              "--rcfile=../scripts/qapi/pylintrc",
+              "../scripts/qapi/",
+              "../docs/sphinx/qapidoc.py",
+              "../docs/sphinx/qapi_domain.py")
+
+    def test_pylint_iotests(self):
+        os.environ['SETUPTOOLS_USE_DISTUTILS'] = 'stdlib'
+        cwd = os.getcwd()
+        try:
+            os.chdir("../tests/qemu-iotests/")
+            pyrun("-m", "linters", "--pylint")
+        finally:
+            os.chdir(cwd)
diff --git a/python/tests/minreqs.txt b/python/tests/minreqs.txt
index 38b17d17e14..19912027076 100644
--- a/python/tests/minreqs.txt
+++ b/python/tests/minreqs.txt
@@ -32,6 +32,7 @@ fusepy==2.0.4
 
 # Test-runners, utilities, etc.
 avocado-framework==90.0
+pytest==6.0.2
 
 # Linters
 flake8==5.0.4
-- 
2.53.0