Remove collect_violations(..., into=) argument (#365)

At risk of Chesterton's fencing myself, but I don't think this argument
is needed or ever used (other than in tests). I can't think of a reason
why someone would want to shove multiple validations into the same
validation, instead of simply calling `collect_violations` multiple
times and combining the lists afterwards.

I did some `git blame` spelunking and it looks like this originally
turned up in #32, but didn't see much reasoning for it in that PR. The
PR mentioned both Pydantic and making things closer to
protovalidate-go's API, but neither seem to have a similar style of
reusing a returned error/exception like this.

Stacked on #364 as these both munge with the exported API & docstrings;
will tag a `v0.15.0` release once all of this is merged.

Author: stefanvanburen

protovalidate/internal/rules.py

@@ -267,11 +267,9 @@ class RuleContext:
 
     _violations: list[Violation]
 
-    def __init__(self, *, fail_fast: bool = False, violations: typing.Optional[list[Violation]] = None):
+    def __init__(self, *, fail_fast: bool = False):
         self._fail_fast = fail_fast
-        if violations is None:
-            violations = []
-        self._violations = violations
+        self._violations = []
 
     @property
     def violations(self) -> list[Violation]:

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
@@ -63,7 +61,6 @@ def collect_violations(
         message: message.Message,
         *,
         fail_fast: bool = False,
-        into: typing.Optional[list[Violation]] = None,
     ) -> list[Violation]:
         """
         Validates the given message against the static rules defined in
@@ -77,12 +74,10 @@ def collect_violations(
         Parameters:
             message: The message to validate.
             fail_fast: If true, validation will stop after the first iteration.
-            into: If provided, any violations will be appended to the
-                Violations object and the same object will be returned.
         Raises:
             CompilationError: If the static rules could not be compiled.
         """
-        ctx = _rules.RuleContext(fail_fast=fail_fast, violations=into)
+        ctx = _rules.RuleContext(fail_fast=fail_fast)
         for rule in self._factory.get(message.DESCRIPTOR):
             rule.validate(ctx, message)
             if ctx.done:

test/test_validate.py

@@ -85,20 +85,6 @@ def test_oneofs(self):
 
         self._run_valid_tests(msg)
 
-    def test_collect_violations_into(self):
-        msg1 = validations_pb2.Oneof()
-        msg1.y = 123
-
-        msg2 = validations_pb2.Oneof()
-        msg2.z.val = True
-
-        for label, v in get_default_validator():
-            with self.subTest(label=label):
-                # Test collect_violations into
-                violations = v.collect_violations(msg1)
-                v.collect_violations(msg2, into=violations)
-                self.assertEqual(len(violations), 0)
-
     def test_protovalidate_oneof_valid(self):
         msg = validations_pb2.ProtovalidateOneof()
         msg.a = "A"