Drop Python 3.8 support (#209)

Python 3.8 is [EOL as of 2024-10-07][1]. This patch:

* Drops support for Python 3.8
* Upgrades our syntax to 3.9
* Re-locks our deps to 3.9

Assuming we do this, our next release should be `v0.6`.

Fixes #202.

[1]: https://devguide.python.org/versions/#unsupported-versions

.github/workflows/ci.yaml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
+        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
     steps:
       - name: Checkout code
         uses: actions/checkout@v4

.github/workflows/conformance.yaml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12", "3.13"]
+        python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
     steps:
       - name: Checkout code
         uses: actions/checkout@v4

protovalidate/internal/constraints.py

@@ -86,7 +86,7 @@ def __getitem__(self, name):
         return super().__getitem__(name)
 
 
-def _msg_to_cel(msg: message.Message) -> typing.Dict[str, celtypes.Value]:
+def _msg_to_cel(msg: message.Message) -> dict[str, celtypes.Value]:
     ctor = _MSG_TYPE_URL_TO_CTOR.get(msg.DESCRIPTOR.full_name)
     if ctor is not None:
         return ctor(msg)
@@ -247,7 +247,7 @@ def validate(self, ctx: ConstraintContext, message: message.Message):  # noqa: A
 class CelConstraintRules(ConstraintRules):
     """A constraint that has rules written in CEL."""
 
-    _runners: typing.List[typing.Tuple[celpy.Runner, validate_pb2.Constraint, typing.Optional[celtypes.Value]]]
+    _runners: list[tuple[celpy.Runner, validate_pb2.Constraint, typing.Optional[celtypes.Value]]]
     _rules_cel: celtypes.Value = None
 
     def __init__(self, rules: typing.Optional[message.Message]):
@@ -259,7 +259,7 @@ def _validate_cel(
         self,
         ctx: ConstraintContext,
         field_name: str,
-        activation: typing.Dict[str, typing.Any],
+        activation: dict[str, typing.Any],
         *,
         for_key: bool = False,
     ):
@@ -280,7 +280,7 @@ def _validate_cel(
     def add_rule(
         self,
         env: celpy.Environment,
-        funcs: typing.Dict[str, celpy.CELFunction],
+        funcs: dict[str, celpy.CELFunction],
         rules: validate_pb2.Constraint,
         *,
         rule: typing.Optional[celtypes.Value] = None,
@@ -335,7 +335,7 @@ class FieldConstraintRules(CelConstraintRules):
     def __init__(
         self,
         env: celpy.Environment,
-        funcs: typing.Dict[str, celpy.CELFunction],
+        funcs: dict[str, celpy.CELFunction],
         field: descriptor.FieldDescriptor,
         field_level: validate_pb2.FieldConstraints,
         *,
@@ -395,13 +395,13 @@ def _validate_value(self, ctx: ConstraintContext, field_path: str, val: typing.A
 class AnyConstraintRules(FieldConstraintRules):
     """Rules for an Any field."""
 
-    _in: typing.List[str] = []  # noqa: RUF012
-    _not_in: typing.List[str] = []  # noqa: RUF012
+    _in: list[str] = []  # noqa: RUF012
+    _not_in: list[str] = []  # noqa: RUF012
 
     def __init__(
         self,
         env: celpy.Environment,
-        funcs: typing.Dict[str, celpy.CELFunction],
+        funcs: dict[str, celpy.CELFunction],
         field: descriptor.FieldDescriptor,
         field_level: validate_pb2.FieldConstraints,
     ):
@@ -437,7 +437,7 @@ class EnumConstraintRules(FieldConstraintRules):
     def __init__(
         self,
         env: celpy.Environment,
-        funcs: typing.Dict[str, celpy.CELFunction],
+        funcs: dict[str, celpy.CELFunction],
         field: descriptor.FieldDescriptor,
         field_level: validate_pb2.FieldConstraints,
         *,
@@ -469,7 +469,7 @@ class RepeatedConstraintRules(FieldConstraintRules):
     def __init__(
         self,
         env: celpy.Environment,
-        funcs: typing.Dict[str, celpy.CELFunction],
+        funcs: dict[str, celpy.CELFunction],
         field: descriptor.FieldDescriptor,
         field_level: validate_pb2.FieldConstraints,
         item_rules: typing.Optional[FieldConstraintRules],
@@ -505,7 +505,7 @@ class MapConstraintRules(FieldConstraintRules):
     def __init__(
         self,
         env: celpy.Environment,
-        funcs: typing.Dict[str, celpy.CELFunction],
+        funcs: dict[str, celpy.CELFunction],
         field: descriptor.FieldDescriptor,
         field_level: validate_pb2.FieldConstraints,
         key_rules: typing.Optional[FieldConstraintRules],
@@ -557,15 +557,15 @@ class ConstraintFactory:
     """Factory for creating and caching constraints."""
 
     _env: celpy.Environment
-    _funcs: typing.Dict[str, celpy.CELFunction]
-    _cache: typing.Dict[descriptor.Descriptor, typing.Union[typing.List[ConstraintRules], Exception]]
+    _funcs: dict[str, celpy.CELFunction]
+    _cache: dict[descriptor.Descriptor, typing.Union[list[ConstraintRules], Exception]]
 
-    def __init__(self, funcs: typing.Dict[str, celpy.CELFunction]):
+    def __init__(self, funcs: dict[str, celpy.CELFunction]):
         self._env = celpy.Environment(runner_class=InterpretedRunner)
         self._funcs = funcs
         self._cache = {}
 
-    def get(self, descriptor: descriptor.Descriptor) -> typing.List[ConstraintRules]:
+    def get(self, descriptor: descriptor.Descriptor) -> list[ConstraintRules]:
         if descriptor not in self._cache:
             try:
                 self._cache[descriptor] = self._new_constraints(descriptor)
@@ -726,8 +726,8 @@ def _new_field_constraint(
             item_rule = self._new_scalar_field_constraint(field, rules.repeated.items)
         return RepeatedConstraintRules(self._env, self._funcs, field, rules, item_rule)
 
-    def _new_constraints(self, desc: descriptor.Descriptor) -> typing.List[ConstraintRules]:
-        result: typing.List[ConstraintRules] = []
+    def _new_constraints(self, desc: descriptor.Descriptor) -> list[ConstraintRules]:
+        result: list[ConstraintRules] = []
         constraint: typing.Optional[ConstraintRules] = None
         if validate_pb2.message in desc.GetOptions().Extensions:
             message_level = desc.GetOptions().Extensions[validate_pb2.message]

protovalidate/internal/extra_func.py

@@ -226,7 +226,7 @@ def unique(val: celtypes.Value) -> celpy.Result:
     return celtypes.BoolType(len(val) == len(set(val)))
 
 
-def make_extra_funcs(locale: str) -> typing.Dict[str, celpy.CELFunction]:
+def make_extra_funcs(locale: str) -> dict[str, celpy.CELFunction]:
     string_fmt = string_format.StringFormat(locale)
     return {
         # Missing standard functions

protovalidate/validator.py

@@ -12,8 +12,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import typing
-
 from google.protobuf import message
 
 from buf.validate import validate_pb2  # type: ignore
@@ -100,7 +98,7 @@ def __init__(self, msg: str, violations: validate_pb2.Violations):
         super().__init__(msg)
         self.violations = violations
 
-    def errors(self) -> typing.List[validate_pb2.Violation]:
+    def errors(self) -> list[validate_pb2.Violation]:
         """
         Returns the validation errors as a simple Python list, rather than the
         Protobuf-specific collection type used by Violations.

pyproject.toml

@@ -8,9 +8,8 @@ description = "Protocol Buffer Validation for Python"
 readme = "README.md"
 license = { file = "LICENSE" }
 keywords = ["validate", "protobuf", "protocol buffer"]
-requires-python = ">=3.8"
+requires-python = ">=3.9"
 classifiers = [
-  "Programming Language :: Python :: 3.8",
   "Programming Language :: Python :: 3.9",
   "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
@@ -31,7 +30,6 @@ Issues = "https://github.com/bufbuild/protovalidate-python/issues"
 source = "vcs"
 
 [tool.ruff]
-target-version = "py38"
 line-length = 120
 lint.select = [
   "A",