Make minimum Python version 3.9 again

Author: facutuesca

.github/workflows/tests.yml

@@ -11,6 +11,8 @@ jobs:
     strategy:
       matrix:
         python:
+          - "3.9"
+          - "3.10"
           - "3.11"
           - "3.12"
           - "3.13"

CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- The minimum Python version required has been brought back to `3.9`
+  ([#64](https://github.com/trailofbits/pypi-attestations/pull/64)).
+
 ### Fixed
 
 - `python -m pypi_attestations verify` now handles inputs like `dist/*`

pyproject.toml

@@ -17,7 +17,7 @@ dependencies = [
     "sigstore~=3.4",
     "sigstore-protobuf-specs",
 ]
-requires-python = ">=3.11"
+requires-python = ">=3.9"
 
 [tool.setuptools.dynamic]
 version = { attr = "pypi_attestations.__version__" }
@@ -57,6 +57,7 @@ omit = ["src/pypi_attestations/_cli.py", "src/pypi_attestations/__main__.py"]
 mypy_path = "src"
 packages = "pypi_attestations"
 plugins = ["pydantic.mypy"]
+python_version = "3.9"
 allow_redefinition = true
 check_untyped_defs = true
 disallow_incomplete_defs = true
@@ -75,7 +76,7 @@ warn_unused_ignores = true
 
 [tool.ruff]
 line-length = 100
-target-version = "py311"
+target-version = "py39"
 
 [tool.ruff.lint]
 select = ["E", "F", "I", "W", "UP", "ANN", "D", "COM", "ISC", "TCH", "SLF"]
@@ -84,6 +85,9 @@ select = ["E", "F", "I", "W", "UP", "ANN", "D", "COM", "ISC", "TCH", "SLF"]
 # COM812 and ISC001 can cause conflicts when using ruff as a formatter.
 # See https://docs.astral.sh/ruff/formatter/#conflicting-lint-rules.
 ignore = ["ANN101", "ANN102", "D203", "D213", "COM812", "ISC001"]
+# Needed since Pydantic relies on runtime type annotations, and we target Python versions
+# < 3.10. See https://docs.astral.sh/ruff/rules/non-pep604-annotation/#why-is-this-bad
+pyupgrade.keep-runtime-typing = true
 
 [tool.ruff.lint.per-file-ignores]
 

src/pypi_attestations/_impl.py

@@ -7,7 +7,7 @@
 
 import base64
 from enum import Enum
-from typing import TYPE_CHECKING, Annotated, Any, Literal, NewType
+from typing import TYPE_CHECKING, Annotated, Any, Literal, NewType, Optional, Union, get_args
 
 import sigstore.errors
 from annotated_types import MinLen  # noqa: TCH002
@@ -187,7 +187,7 @@ def verify(
         dist: Distribution,
         *,
         staging: bool = False,
-    ) -> tuple[str, dict[str, Any] | None]:
+    ) -> tuple[str, Optional[dict[str, Any]]]:
         """Verify against an existing Python distribution.
 
         The `identity` can be an object confirming to
@@ -203,7 +203,8 @@ def verify(
         # NOTE: Can't do `isinstance` with `Publisher` since it's
         # a `_GenericAlias`; instead we punch through to the inner
         # `_Publisher` union.
-        if isinstance(identity, _Publisher):
+        # Use of typing.get_args is needed for Python > 3.10
+        if isinstance(identity, get_args(_Publisher)):
             policy = identity._as_policy()  # noqa: SLF001
         else:
             policy = identity
@@ -387,7 +388,7 @@ class _PublisherBase(BaseModel):
     model_config = ConfigDict(alias_generator=to_snake)
 
     kind: str
-    claims: dict[str, Any] | None = None
+    claims: Optional[dict[str, Any]] = None
 
     def _as_policy(self) -> VerificationPolicy:
         """Return an appropriate `sigstore.policy.VerificationPolicy` for this publisher."""
@@ -483,7 +484,7 @@ class GitHubPublisher(_PublisherBase):
     action.
     """
 
-    environment: str | None = None
+    environment: Optional[str] = None
     """
     The optional name GitHub Actions environment that the publishing
     action was performed from.
@@ -505,7 +506,7 @@ class GitLabPublisher(_PublisherBase):
     `bar` owned by group `foo` and subgroup `baz`.
     """
 
-    environment: str | None = None
+    environment: Optional[str] = None
     """
     The optional environment that the publishing action was performed from.
     """
@@ -531,7 +532,7 @@ def _as_policy(self) -> VerificationPolicy:
         return policy.AllOf(policies)
 
 
-_Publisher = GitHubPublisher | GitLabPublisher
+_Publisher = Union[GitHubPublisher, GitLabPublisher]
 Publisher = Annotated[_Publisher, Field(discriminator="kind")]
 
 

test/test_impl.py

@@ -4,7 +4,7 @@
 import os
 from hashlib import sha256
 from pathlib import Path
-from typing import Any
+from typing import Any, Optional
 
 import pretend
 import pytest
@@ -133,7 +133,7 @@ def test_verify_github_attested(self) -> None:
         assert predicate == {}
 
     @pytest.mark.parametrize("claims", (None, {}, {"ref": "refs/tags/v0.0.4a2"}))
-    def test_verify_from_github_publisher(self, claims: dict | None) -> None:
+    def test_verify_from_github_publisher(self, claims: Optional[dict]) -> None:
         publisher = impl.GitHubPublisher(
             repository="trailofbits/pypi-attestation-models",
             workflow="release.yml",
@@ -556,7 +556,7 @@ def test_as_policy(self) -> None:
         assert len(pol._children) == 3
 
     @pytest.mark.parametrize("claims", [None, {}, {"something": "unrelated"}, {"ref": None}])
-    def test_as_policy_invalid(self, claims: dict | None) -> None:
+    def test_as_policy_invalid(self, claims: Optional[dict]) -> None:
         publisher = impl.GitLabPublisher(repository="fake/fake", claims=claims)
 
         with pytest.raises(impl.VerificationError, match="refusing to build a policy"):
@@ -600,7 +600,8 @@ class TestBase64Bytes:
     def test_decoding(self) -> None:
         # This raises when using our custom type. When using Pydantic's Base64Bytes,
         # this succeeds
-        with pytest.raises(ValueError, match="Only base64 data is allowed"):
+        # The exception message is different in Python 3.9 vs >=3.10
+        with pytest.raises(ValueError, match="Non-base64 digit found|Only base64 data is allowed"):
             DummyModel(base64_bytes=b"a\n\naaa")
 
     def test_encoding(self) -> None: