refactor(testing): type proof_setting as an IntEnum and fix its derivation

packages/testing/src/consensus_testing/pytest_plugins/filler.py

@@ -13,7 +13,12 @@
 from consensus_testing.crypto_mode import AggregationProver, CryptoMode
 from consensus_testing.forks import FORKS_BY_NAME
 from consensus_testing.keys import DEFAULT_MAX_SLOT, XmssKeyManager
-from consensus_testing.test_fixtures import FIXTURE_FORMATS, FixtureInfo
+from consensus_testing.test_fixtures import (
+    FIXTURE_FORMATS,
+    PROOF_FAILURE_REJECTION_REASONS,
+    FixtureInfo,
+    ProofSetting,
+)
 from lean_spec.spec.forks import Slot, ValidatorIndex
 from lean_spec.spec.ssz import Bytes32
 
@@ -450,15 +455,19 @@ def fill_and_collect(**spec_fields: Any) -> Any:
             else:
                 generated_fixture = test_spec.generate()
 
-            # - 0 mocked,
-            # - 1 real and must verify,
-            # - 2 real and must fail verification.
+            # A mocked proof is never verified.
+            # A real proof must fail only when the rejection is itself a proof failure.
+            # A non-crypto rejection (such as an unknown parent) still carries a valid proof.
+            expected_rejection = test_spec.expected_rejection
             if mock_prover:
-                proof_setting = 0
-            elif test_spec.expected_rejection is not None:
-                proof_setting = 2
+                proof_setting = ProofSetting.MOCKED
+            elif (
+                expected_rejection is not None
+                and expected_rejection.reason in PROOF_FAILURE_REJECTION_REASONS
+            ):
+                proof_setting = ProofSetting.REAL_AND_INVALID
             else:
-                proof_setting = 1
+                proof_setting = ProofSetting.REAL_AND_VALID
 
             filled_fixture = generated_fixture.with_info(
                 info=FixtureInfo(

packages/testing/src/consensus_testing/test_fixtures/__init__.py

@@ -2,10 +2,12 @@
 
 from consensus_testing.test_fixtures.api_endpoint import ApiEndpointFixture, ApiEndpointTest
 from consensus_testing.test_fixtures.base import (
+    PROOF_FAILURE_REJECTION_REASONS,
     BaseConsensusFixture,
     BaseTestSpec,
     ExpectedRejection,
     FixtureInfo,
+    ProofSetting,
 )
 from consensus_testing.test_fixtures.fork_choice import ForkChoiceFixture, ForkChoiceTest
 from consensus_testing.test_fixtures.gossipsub_handler import (
@@ -159,6 +161,8 @@
     "BaseTestSpec",
     "ExpectedRejection",
     "FixtureInfo",
+    "ProofSetting",
+    "PROOF_FAILURE_REJECTION_REASONS",
     "StateTransitionFixture",
     "StateTransitionTest",
     "ForkChoiceFixture",

packages/testing/src/consensus_testing/test_fixtures/base.py

@@ -3,6 +3,7 @@
 import hashlib
 import json
 from abc import abstractmethod
+from enum import IntEnum
 from functools import cached_property
 from typing import Any, ClassVar, Self
 
@@ -58,6 +59,25 @@ class ExpectedRejection(StrictBaseModel):
     """
 
 
+class ProofSetting(IntEnum):
+    """Aggregation proof regime emitted with each fixture."""
+
+    MOCKED = 0
+    """The proof is mocked and must not be verified."""
+
+    REAL_AND_VALID = 1
+    """The proof is real and must verify."""
+
+    REAL_AND_INVALID = 2
+    """The proof is real and must fail verification."""
+
+
+PROOF_FAILURE_REJECTION_REASONS: frozenset[RejectionReason] = frozenset(
+    {RejectionReason.INVALID_SIGNATURE, RejectionReason.INVALID_BLOCK_PROOF}
+)
+"""Rejection reasons whose direct cause is the aggregation proof failing to verify."""
+
+
 class BaseConsensusFixture(CamelModel):
     """
     Base class for all consensus test fixtures.
@@ -93,14 +113,8 @@ class BaseConsensusFixture(CamelModel):
     This is the field clients assert against.
     """
 
-    proof_setting: int = 0
-    """
-    Aggregation proof regime, mirroring eth2's bls_setting.
-
-    - 0 means the proof is mocked and must not be verified.
-    - 1 means the proof is real and must verify.
-    - 2 means the proof is real and must fail verification.
-    """
+    proof_setting: ProofSetting = ProofSetting.MOCKED
+    """Aggregation proof regime, emitted as an integer; each value documents its own meaning."""
 
     def with_info(self, info: FixtureInfo, network: str) -> Self:
         """