Test with Python 3.9 as well

.github/workflows/main.yaml

@@ -22,14 +22,17 @@ jobs:
         - py36-tox35
         - py37-tox35
         - py38-tox35
+        - py39-tox35
 
         - py36-toxrelease
         - py37-toxrelease
         - py38-toxrelease
+        - py39-toxrelease
 
         - py36-toxmaster
         - py37-toxmaster
         - py38-toxmaster
+        - py39-toxmaster
 
     # Use GitHub's Linux Docker host
     runs-on: ubuntu-latest

README.rst

@@ -214,8 +214,8 @@ or send Pull Requests.
 Tests
 ~~~~~
 
-In order to run the tests, you'll need ``tox`` and Python 3.6, 3.7 and 3.8 installed.
-The integration tests assume all three are available.
+In order to run the tests, you'll need ``tox`` and Python 3.6, 3.7, 3.8 and 3.9 installed.
+The integration tests assume all four are available.
 On Fedora, you just need to ``dnf install tox``.
 
 Run ``tox`` to invoke the tests.

setup.py

@@ -30,6 +30,7 @@ setup(
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: Implementation :: CPython",
         "Topic :: Software Development :: Testing",
     ],

tests/fixtures/tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py36,py37,py38
+envlist = py36,py37,py38,py39
 
 [testenv]
 deps =

tests/test_integration.py

@@ -49,17 +49,14 @@ def is_available(python):
 
 
 TOX_VERSION = version.parse(tox("--version").stdout.split(" ")[0])
+TOX38 = TOX_VERSION >= version.parse("3.8")
+needs_tox38 = pytest.mark.skipif(not TOX38, reason="This test needs at least tox 3.8")
 
-needs_py3678 = pytest.mark.skipif(
-    not is_available("python3.6")
-    or not is_available("python3.7")
-    or not is_available("python3.8"),
-    reason="This test needs all of python3.6, python3.7 and python3.8 to be available in $PATH",
+needs_py36789 = pytest.mark.skipif(
+    not all((is_available(f"python3.{x}") for x in range(6, 10))),
+    reason="This test needs python3.6, 3.7, 3.8 and 3.9 available in $PATH",
 )
 
-needs_tox38 = pytest.mark.skipif(
-    TOX_VERSION < version.parse("3.8"), reason="This test needs at least tox 3.8"
-)
 
 
 def test_native_toxenv_current_env():
@@ -68,7 +65,7 @@ def test_native_toxenv_current_env():
     assert not (DOT_TOX / NATIVE_TOXENV / "lib").is_dir()
 
 
-@needs_py3678
+@needs_py36789
 def test_all_toxenv_current_env():
     result = tox("--current-env", check=False)
     assert NATIVE_EXEC_PREFIX_MSG in result.stdout.splitlines()
@@ -87,7 +84,7 @@ def test_missing_toxenv_current_env(python):
     assert result.returncode > 0
 
 
-@needs_py3678
+@needs_py36789
 def test_all_toxenv_current_env_skip_missing():
     result = tox("--current-env", "--skip-missing-interpreters", check=False)
     assert "InterpreterMismatch:" in result.stdout
@@ -95,7 +92,7 @@ def test_all_toxenv_current_env_skip_missing():
     assert result.returncode == 0
 
 
-@pytest.mark.parametrize("toxenv", ["py36", "py37", "py38"])
+@pytest.mark.parametrize("toxenv", ["py36", "py37", "py38", "py39"])
 def test_print_deps_only(toxenv):
     result = tox("-e", toxenv, "--print-deps-only")
     expected = textwrap.dedent(
@@ -120,17 +117,20 @@ def test_allenvs_print_deps_only():
         py
         six
         py
+        six
+        py
         ___________________________________ summary ____________________________________
           py36: commands succeeded
           py37: commands succeeded
           py38: commands succeeded
+          py39: commands succeeded
           congratulations :)
         """
     ).lstrip()
     assert result.stdout == expected
 
 
-@pytest.mark.parametrize("toxenv", ["py36", "py37", "py38"])
+@pytest.mark.parametrize("toxenv", ["py36", "py37", "py38", "py39"])
 def test_print_deps_to_file(toxenv, tmp_path):
     depspath = tmp_path / "deps"
     result = tox("-e", toxenv, "--print-deps-to-file", str(depspath))
@@ -148,13 +148,14 @@ def test_print_deps_to_file(toxenv, tmp_path):
 def test_allenvs_print_deps_to_file(tmp_path):
     depspath = tmp_path / "deps"
     result = tox("--print-deps-to-file", str(depspath))
-    assert depspath.read_text().splitlines() == ["six", "py"] * 3
+    assert depspath.read_text().splitlines() == ["six", "py"] * 4
     expected = textwrap.dedent(
         """
         ___________________________________ summary ____________________________________
           py36: commands succeeded
           py37: commands succeeded
           py38: commands succeeded
+          py39: commands succeeded
           congratulations :)
         """
     ).lstrip()
@@ -184,15 +185,19 @@ def test_print_deps_only_print_deps_to_file_are_mutually_exclusive():
     assert "cannot be used together" in result.stderr
 
 
-@needs_py3678
+@needs_py36789
 def test_regular_run():
     result = tox()
-    lines = sorted(result.stdout.splitlines()[:3])
+    lines = sorted(result.stdout.splitlines()[:4])
     assert "/.tox/py36 is the exec_prefix" in lines[0]
     assert "/.tox/py37 is the exec_prefix" in lines[1]
     assert "/.tox/py38 is the exec_prefix" in lines[2]
+    assert "/.tox/py39 is the exec_prefix" in lines[3]
     assert "congratulations" in result.stdout
-    for y in 6, 7, 8:
+    for y in 6, 7, 8, 9:
+        if y == 9 and not TOX38:
+            # tox 3.5 cannot handle Python 3.9 venvs
+            continue
         for pkg in "py", "six", "test":
             sitelib = DOT_TOX / f"py3{y}/lib/python3.{y}/site-packages"
             assert sitelib.is_dir()

tox.ini

@@ -2,7 +2,7 @@
 
 # This information is repeated in .github/workflows/main.yaml
 # (see https://github.com/fedora-python/tox-github-action/issues/8)
-envlist = {py36,py37,py38}-tox{35,release,master}
+envlist = {py36,py37,py38,py39}-tox{35,release,master}
 
 [testenv]
 deps=