Initial, read-only support for GitHub Actions

See #22.

CHANGES.rst

@@ -1,10 +1,11 @@
 Changelog
 =========
 
-0.16.2 (unreleased)
+0.17.0 (unreleased)
 -------------------
 
-- Nothing changed yet.
+- Initial supprot for GitHub Actions (`issue 22
+  <https://github.com/mgedmin/check-python-versions/issues/22>`_).
 
 
 0.16.1 (2020-11-08)

src/check_python_versions/cli.py

@@ -255,6 +255,8 @@ def update_versions(
     replacements: ReplacementDict = {}
 
     for source in ALL_SOURCES:
+        if source.update is None:
+            continue
         if only and source.filename not in only:
             continue
         pathname = os.path.join(where, source.filename)

src/check_python_versions/sources/all.py

@@ -3,6 +3,7 @@
 from .setup_py import SetupClassifiers, SetupPythonRequires
 from .tox import Tox
 from .travis import Travis
+from .github import GitHubActions
 
 
 # The order here is only mildly important: it's used for presentation.
@@ -13,6 +14,7 @@
     SetupPythonRequires,
     Tox,
     Travis,
+    GitHubActions,
     Appveyor,
     Manylinux,
 ]

src/check_python_versions/sources/base.py

@@ -13,4 +13,4 @@ class Source(typing.NamedTuple):
     title: str
     filename: str
     extract: ExtractorFn
-    update: UpdaterFn
+    update: Optional[UpdaterFn] = None

src/check_python_versions/sources/github.py

@@ -0,0 +1,77 @@
+"""
+Support for GitHub Actions.
+
+GitHub Actions are very flexible, so this code is going to make some
+simplifying assumptions:
+
+- your workflow is in .github/workflows/tests.yml
+- you use a matrix strategy
+  - on 'python-version' that contains python versions, or
+  - on 'config' that contains lists of [python_version, tox_env]
+"""
+
+from typing import List, Union
+
+import yaml
+
+from .base import Source
+from ..utils import FileOrFilename, open_file
+from ..versions import SortedVersionList, Version
+
+
+GHA_WORKFLOW_FILE = '.github/workflows/tests.yml'
+
+
+def get_gha_python_versions(
+    filename: FileOrFilename = GHA_WORKFLOW_FILE,
+) -> SortedVersionList:
+    """Extract supported Python versions from a GitHub workflow."""
+    with open_file(filename) as fp:
+        conf = yaml.safe_load(fp)
+
+    versions: List[Version] = []
+    for job_name, job in conf.get('jobs', {}).items():
+        matrix = job.get('strategy', {}).get('matrix', {})
+        if 'python-version' in matrix:
+            versions.extend(
+                e for e in map(parse_gh_ver, matrix['python-version']) if e)
+        if 'config' in matrix:
+            versions.extend(
+                parse_gh_ver(c[0])
+                for c in matrix['config']
+                if isinstance(c, list)
+            )
+
+    return sorted(set(versions))
+
+
+def parse_gh_ver(v: Union[str, float]) -> Version:
+    """Parse Python versions used for actions/setup-python@v2.
+
+    This format is not fully well documented.  There's support for
+    specifying things like
+
+    - "3.x" (latest minor in Python 3.x; currently 3.9)
+    - "3.7" (latest bugfix in Python 3.7)
+    - "3.7.2" (specific version to be downloaded and installed)
+    - "pypy2"/"pypy3"
+
+    https://github.com/actions/python-versions/blob/main/versions-manifest.json
+    contains a list of supported CPython versions that can be downloaded
+    and installed; this includes prereleases, but doesn't include PyPy.
+    """
+    v = str(v)
+    if v.startswith('pypy3'):
+        return Version.from_string('PyPy3')
+    elif v.startswith('pypy2'):
+        return Version.from_string('PyPy')
+    else:
+        return Version.from_string(v)
+
+
+GitHubActions = Source(
+    title=GHA_WORKFLOW_FILE,
+    filename=GHA_WORKFLOW_FILE,
+    extract=get_gha_python_versions,
+    update=None,
+)

tests/sources/test_github.py

@@ -0,0 +1,115 @@
+import textwrap
+from io import StringIO
+from typing import List
+
+import pytest
+
+from check_python_versions.sources.github import (
+    get_gha_python_versions,
+    parse_gh_ver,
+)
+from check_python_versions.versions import Version
+
+
+def v(versions: List[str]) -> List[Version]:
+    return [Version.from_string(v) for v in versions]
+
+
+def test_get_gha_python_versions():
+    tests_yml = StringIO(textwrap.dedent("""\
+        name: Python package
+        on: [push]
+        jobs:
+          build:
+            runs-on: ubuntu-latest
+            strategy:
+              matrix:
+                python-version: [2.7, 3.5, 3.6, 3.7, 3.8]
+            steps:
+            - uses: actions/checkout@v2
+            - name: Set up Python ${{ matrix.python-version }}
+              uses: actions/setup-python@v2
+              with:
+                python-version: ${{ matrix.python-version }}
+            - name: Install dependencies
+              run: |
+                python -m pip install --upgrade pip
+                pip install pytest
+                pip install -r requirements.txt
+            - name: Test with pytest
+              run: |
+                pytest
+    """))
+    tests_yml.name = '.github/workflows/tests.yml'
+    assert get_gha_python_versions(tests_yml) == v([
+        '2.7', '3.5', '3.6', '3.7', '3.8',
+    ])
+
+
+def test_get_gha_python_versions_zopefoundation():
+    tests_yml = StringIO(textwrap.dedent("""\
+        name: tests
+        on:
+          push:
+            branches: [ master ]
+          pull_request:
+          schedule:
+            - cron: '0 12 * * 0'  # run once a week on Sunday
+        jobs:
+          build:
+            strategy:
+              matrix:
+                config:
+                # [Python version, tox env]
+                - ["3.8",   "lint"]
+                - ["2.7",   "py27"]
+                - ["3.5",   "py35"]
+                - ["3.6",   "py36"]
+                - ["3.7",   "py37"]
+                - ["3.8",   "py38"]
+                - ["3.9",   "py39"]
+                - ["pypy2", "pypy"]
+                - ["pypy3", "pypy3"]
+                - ["3.8",   "coverage"]
+
+            runs-on: ubuntu-latest
+            name: ${{ matrix.config[1] }}
+            steps:
+            - uses: actions/checkout@v2
+            - name: Set up Python
+              uses: actions/setup-python@v2
+              with:
+                python-version: ${{ matrix.config[0] }}
+            - ...
+    """))
+    tests_yml.name = '.github/workflows/tests.yml'
+    assert get_gha_python_versions(tests_yml) == v([
+        '2.7', '3.5', '3.6', '3.7', '3.8', '3.9', 'PyPy', 'PyPy3',
+    ])
+
+
+def test_get_gha_python_versions_no_version_matrix():
+    tests_yml = StringIO(textwrap.dedent("""\
+        name: Python package
+        on: [push]
+        jobs:
+          build:
+            runs-on: ${{ matrix.os }}
+            strategy:
+              matrix:
+                os: [ubuntu-latest, macos-latest, windows-latest]
+            steps:
+            - ...
+    """))
+    tests_yml.name = '.github/workflows/tests.yml'
+    assert get_gha_python_versions(tests_yml) == []
+
+
+@pytest.mark.parametrize('s, expected', [
+    (3.6, '3.6'),
+    ('3.7', '3.7'),
+    ('pypy2', 'PyPy'),
+    ('pypy3', 'PyPy3'),
+])
+def test_parse_gh_ver(s, expected):
+    assert parse_gh_ver(s) == Version.from_string(expected)

tests/test_cli.py

@@ -104,7 +104,7 @@ def test_check_unknown(tmp_path, capsys):
     """))
     assert cpv.check_versions(tmp_path) is True
     assert capsys.readouterr().out == textwrap.dedent("""\
-        setup.py says:              (empty)
+        setup.py says:                    (empty)
     """)
 
 
@@ -122,7 +122,7 @@ def test_check_minimal(tmp_path, capsys):
     """))
     assert cpv.check_versions(tmp_path) is True
     assert capsys.readouterr().out == textwrap.dedent("""\
-        setup.py says:              2.7, 3.6
+        setup.py says:                    2.7, 3.6
     """)
 
 
@@ -145,8 +145,8 @@ def test_check_mismatch(tmp_path, capsys):
     """))
     assert cpv.check_versions(tmp_path) is False
     assert capsys.readouterr().out == textwrap.dedent("""\
-        setup.py says:              2.7, 3.6
-        tox.ini says:               2.7
+        setup.py says:                    2.7, 3.6
+        tox.ini says:                     2.7
     """)
 
 
@@ -164,8 +164,8 @@ def test_check_expectation(tmp_path, capsys):
     """))
     assert not cpv.check_versions(tmp_path, expect=v(['2.7', '3.6', '3.7']))
     assert capsys.readouterr().out == textwrap.dedent("""\
-        setup.py says:              2.7, 3.6
-        expected:                   2.7, 3.6, 3.7
+        setup.py says:                    2.7, 3.6
+        expected:                         2.7, 3.6, 3.7
     """)
 
 
@@ -188,7 +188,7 @@ def test_check_only(tmp_path, capsys):
     """))
     assert cpv.check_versions(tmp_path, only='tox.ini')
     assert capsys.readouterr().out == textwrap.dedent("""\
-        tox.ini says:               2.7
+        tox.ini says:                     2.7
     """)
 
 
@@ -525,8 +525,8 @@ def test_main_only(monkeypatch, capsys, tmp_path):
     assert (
         capsys.readouterr().out + '\n'
     ).replace(str(tmp_path) + os.path.sep, 'tmp/') == textwrap.dedent("""\
-        setup.py says:              2.7, 3.6
-        tox.ini says:               2.7, 3.6
+        setup.py says:                    2.7, 3.6
+        tox.ini says:                     2.7, 3.6
 
     """)
 
@@ -556,8 +556,8 @@ def test_main_multiple(monkeypatch, capsys, tmp_path):
     ).replace(str(tmp_path) + os.path.sep, 'tmp/') == textwrap.dedent("""\
         tmp/a:
 
-        setup.py says:              2.7, 3.6
-        expected:                   3.6, 3.7
+        setup.py says:                    2.7, 3.6
+        expected:                         3.6, 3.7
 
 
         tmp/b:
@@ -640,7 +640,7 @@ def test_main_update(monkeypatch, capsys, tmp_path):
 
         Write changes to tmp/setup.py? [y/N]
 
-        setup.py says:              2.7, 3.6, 3.7, 3.8
+        setup.py says:                    2.7, 3.6, 3.7, 3.8
     """)
     assert (tmp_path / "setup.py").read_text() == textwrap.dedent("""\
         from setuptools import setup
@@ -693,7 +693,7 @@ def test_main_update_rejected(monkeypatch, capsys, tmp_path):
 
         Write changes to tmp/setup.py? [y/N]
 
-        setup.py says:              2.7, 3.6
+        setup.py says:                    2.7, 3.6
     """)
     assert (tmp_path / "setup.py").read_text() == textwrap.dedent("""\
         from setuptools import setup
@@ -779,7 +779,7 @@ def test_main_update_dry_run(monkeypatch, capsys, tmp_path):
         .expandtabs()
         .replace(' \n', '\n\n')
     ) == textwrap.dedent("""\
-        setup.py says:              2.7, 3.6, 3.7, 3.8
+        setup.py says:                    2.7, 3.6, 3.7, 3.8
     """)
     assert (tmp_path / "setup.py").read_text() == textwrap.dedent("""\
         from setuptools import setup