fix: Add support for Python 3.11 (#329)

* Adjust to enum changes in Python 3.11.0b3

There are two changes:

Changes in the actual code:

 - _member_names changed from a list to a dict in python/cpython#28907
    - we instance-check and remove by list-specific or dict-specific way

Change in the tests only:

 - accessing other enum members via instance attributes is no longer possible
    - we access them via the class instead
    - we leave the original test in a try-except block

Some of the Python enum changes might get reverted,
see python/cpython#93910
But the fix is backwards compatible.

Fixes #326

* ci: unit test session with python 3.11.0-beta.3

* ci: add python v3.11.0-beta.3 to noxfile.py

* another attempt to get python 3.11.0b3 working in github actions

* ci: use python 3.8 for docs check

* ci: fix docs build

* fix ci

* mark python 3.11 tests as required

* add python 3.11 to setup.py

* fix docs build

* remove python 3.11 test for unitcpp

* remove python 3.11 test for unitcpp

* remove python 3.11 test for unitcpp

* attempt to fix exclude in github action

Co-authored-by: Anthonios Partheniou <partheniou@google.com>

.github/sync-repo-settings.yaml

@@ -16,6 +16,7 @@ branchProtectionRules:
     - 'unit (3.9)'
     - 'unit (3.10, cpp)'
     - 'unit (3.10)'
+    - 'unit (3.11)'
     - cover
     - OwlBot Post Processor
     - 'cla/google'

.github/workflows/tests.yml

@@ -30,20 +30,23 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - name: Set up Python 3.8
+      - name: Set up Python 3.9
         uses: actions/setup-python@v4
         with:
-          python-version: "3.10"
+          python-version: "3.9"
       - name: Install nox.
         run: python -m pip install nox
       - name: Build the documentation.
         run: nox -s docs
   unit:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     strategy:
       matrix:
-        python: ['3.6', '3.7', '3.8', '3.9', '3.10']
+        python: ['3.6', '3.7', '3.8', '3.9', '3.10', '3.11']
         variant: ['', 'cpp', 'upb']
+        exclude:
+          - variant: "cpp"
+            python: 3.11
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python ${{ matrix.python }}
@@ -53,16 +56,22 @@ jobs:
       - name: Install nox
         run: |
           pip install nox
+        # Trim the Python version string
+      - name: Trim python version
+        run: |
+          PYTHON_VERSION_TRIMMED=${{ matrix.python }}
+          PYTHON_VERSION_TRIMMED=$(echo $PYTHON_VERSION_TRIMMED | cut -c1-4)
+          echo "PYTHON_VERSION_TRIMMED=$PYTHON_VERSION_TRIMMED" >> $GITHUB_ENV
       - name: Run unit tests
         env:
-          COVERAGE_FILE: .coverage-${{ matrix.variant }}-${{ matrix.python }}
+          COVERAGE_FILE: .coverage-${{ matrix.variant }}-${{ env.PYTHON_VERSION_TRIMMED }}
         run: |
-          nox -s unit${{ matrix.variant }}-${{ matrix.python }}
+          nox -s unit${{ matrix.variant }}-${{ env.PYTHON_VERSION_TRIMMED }}
       - name: Upload coverage results
         uses: actions/upload-artifact@v3
         with:
           name: coverage-artifacts
-          path: .coverage-${{ matrix.variant }}-${{ matrix.python }}
+          path: .coverage-${{ matrix.variant }}-${{ env.PYTHON_VERSION_TRIMMED }}
   cover:
     runs-on: ubuntu-latest
     needs:

docs/conf.py

@@ -64,7 +64,7 @@
 #
 # This is also used if you do content translation via gettext catalogs.
 # Usually you set "language" from the command line for these cases.
-language = None
+language = "en"
 
 # List of patterns, relative to source directory, that match files and
 # directories to ignore when looking for source files.

noxfile.py

@@ -28,8 +28,12 @@
     "3.8",
     "3.9",
     "3.10",
+    "3.11",
 ]
 
+# Error if a python version is missing
+nox.options.error_on_missing_interpreters = True
+
 
 @nox.session(python=PYTHON_VERSIONS)
 def unit(session, proto="python"):
@@ -64,7 +68,7 @@ def unit(session, proto="python"):
 # Check if protobuf has released wheels for new python versions
 # https://pypi.org/project/protobuf/#files
 # This list will generally be shorter than 'unit'
-@nox.session(python=PYTHON_VERSIONS)
+@nox.session(python=["3.6", "3.7", "3.8", "3.9", "3.10"])
 def unitcpp(session):
     return unit(session, proto="cpp")
 
@@ -74,8 +78,7 @@ def unitupb(session):
     return unit(session, proto="upb")
 
 
-# Just use the most recent version for docs
-@nox.session(python=PYTHON_VERSIONS[-1])
+@nox.session(python="3.9")
 def docs(session):
     """Build the docs."""
 

proto/enums.py

@@ -58,8 +58,11 @@ def __new__(mcls, name, bases, attrs):
         # In 3.7 onwards, we can define an _ignore_ attribute and do some
         # mucking around with that.
         if pb_options in attrs._member_names:
-            idx = attrs._member_names.index(pb_options)
-            attrs._member_names.pop(idx)
+            if isinstance(attrs._member_names, list):
+                idx = attrs._member_names.index(pb_options)
+                attrs._member_names.pop(idx)
+            else:  # Python 3.11.0b3
+                del attrs._member_names[pb_options]
 
         # Make the descriptor.
         enum_desc = descriptor_pb2.EnumDescriptorProto(

setup.py

@@ -55,6 +55,7 @@
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
+        "Programming Language :: Python :: 3.11",
         "Topic :: Software Development :: Code Generators",
         "Topic :: Software Development :: Libraries :: Python Modules",
     ],

tests/test_enum_total_ordering.py

@@ -49,7 +49,11 @@ def test_total_ordering_w_other_enum_type():
 
     for item in enums_test.OtherEnum:
         assert not to_compare == item
-        assert to_compare.SOME_VALUE != item
+        assert type(to_compare).SOME_VALUE != item
+        try:
+            assert to_compare.SOME_VALUE != item
+        except AttributeError:  # Python 3.11.0b3
+            pass
         with pytest.raises(TypeError):
             assert not to_compare < item
         with pytest.raises(TypeError):