Infra: Improve tests and coverage configuration (#4715)

Author: AA-Turner

.pytest.toml

@@ -0,0 +1,35 @@
+# https://docs.pytest.org/en/stable/reference/customize.html
+
+[pytest]
+minversion = "9.0"
+
+# https://docs.pytest.org/en/stable/reference/reference.html#command-line-flags
+addopts = [
+    # Show extra summary information for all non-passing tests
+    "-r a",
+    # https://docs.pytest.org/en/stable/explanation/pythonpath.html#import-modes
+    "--import-mode=importlib",
+    # https://pytest-cov.readthedocs.io/en/latest/config.html#reference
+    "--cov=check_peps",
+    "--cov=pep_sphinx_extensions",
+    "--cov-report=html",
+    "--cov-report=xml",
+]
+
+# Fail if pytest.mark.parametrize() has no parameters
+empty_parameter_set_mark = "fail_at_collect"
+
+filterwarnings = ["error"]
+
+testpaths = [
+    "pep_sphinx_extensions",
+]
+
+# https://docs.pytest.org/en/stable/reference/reference.html#confval-strict
+strict_config = true
+strict_markers = true
+strict_parametrization_ids = true
+strict_xfail = true
+
+# Various tests use Unicode in pytest.mark.parametrize().
+disable_test_id_escaping_and_forfeit_all_rights_to_community_support = true

pytest.ini

@@ -7,7 +7,7 @@ docutils >= 0.19.0
 sphinx-notfound-page >= 1.0.2
 
 # For tests
-pytest
+pytest>=9
 pytest-cov
 
 # For python-releases.toml

requirements.txt

@@ -12,3 +12,12 @@ pass_env =
     FORCE_COLOR
 commands =
     python -bb -X dev -W error -m pytest {posargs}
+
+[coverage:run]
+omit =
+    */__main__.py  # Ignore all __main__.py files
+    peps/*         # Ignore all files in the PEPs folder
+
+[coverage:report]
+exclude_also =
+    if __name__ == .__main__.: