revert(forks): drop SigScheme capability and @requires marker (#715)

packages/testing/src/framework/__init__.py

@@ -4,7 +4,3 @@
 This module provides base classes and utilities that are common across
 both consensus and execution layer testing.
 """
-
-from .markers import requires_capability
-
-__all__ = ["requires_capability"]

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

@@ -1,6 +1,5 @@
 """Layer-agnostic pytest plugin for generating Ethereum test fixtures."""
 
-import functools
 import importlib
 import json
 import shutil
@@ -13,13 +12,6 @@
 import pytest
 
 
-@functools.cache
-def _spec_instance_for(fork_class: type) -> Any:
-    """Build the active fork's spec instance once and reuse across collection."""
-    spec_class_method: Any = fork_class.spec_class  # ty: ignore[unresolved-attribute]
-    return spec_class_method()()
-
-
 class FixtureCollector:
     """Collects generated fixtures and writes them to disk."""
 
@@ -234,11 +226,6 @@ def pytest_configure(config: pytest.Config) -> None:
         "markers",
         "valid_at(fork): specifies at which fork a test case is valid",
     )
-    config.addinivalue_line(
-        "markers",
-        "requires(*capabilities): only collect when the active fork "
-        "advertises every listed runtime-checkable Protocol",
-    )
 
     # Get options
     output_dir = Path(config.getoption("--output"))
@@ -326,14 +313,6 @@ def _check_markers_valid_for_fork(
     """Check if test markers indicate validity for the given fork.
 
     Shared logic for both collection-time and parametrization-time fork filtering.
-
-    Composition rules:
-
-    - Fork-range markers form an intersection across kinds and a union
-      within a kind.
-    - The exact-fork marker short-circuits to a single-fork match.
-    - The capability marker AND-composes on top of either branch — the
-      active fork must satisfy every listed capability Protocol.
     """
     has_valid_from = False
     has_valid_until = False
@@ -342,7 +321,6 @@ def _check_markers_valid_for_fork(
     valid_from_forks = []
     valid_until_forks = []
     valid_at_forks = []
-    required_capabilities: list[type] = []
 
     for marker in markers:
         if marker.name == "valid_from":
@@ -363,21 +341,12 @@ def _check_markers_valid_for_fork(
                 target_fork = get_fork_by_name(fork_name)
                 if target_fork:
                     valid_at_forks.append(target_fork)
-        elif marker.name == "requires":
-            required_capabilities.extend(marker.args)
-
-    def _capability_check() -> bool:
-        """Active fork must structurally satisfy every required capability."""
-        if not required_capabilities:
-            return True
-        spec = _spec_instance_for(fork_class)
-        return all(isinstance(spec, cap) for cap in required_capabilities)
 
-    if not (has_valid_from or has_valid_until or has_valid_at or required_capabilities):
+    if not (has_valid_from or has_valid_until or has_valid_at):
         return True
 
     if has_valid_at:
-        return fork_class in valid_at_forks and _capability_check()
+        return fork_class in valid_at_forks
 
     from_valid = True
     if has_valid_from:
@@ -387,7 +356,7 @@ def _capability_check() -> bool:
     if has_valid_until:
         until_valid = any(fork_class <= until_fork for until_fork in valid_until_forks)
 
-    return from_valid and until_valid and _capability_check()
+    return from_valid and until_valid
 
 
 def _is_test_item_valid_for_fork(

pyproject.toml

@@ -111,10 +111,7 @@ addopts = [
 ]
 markers = [
     "slow: marks tests as slow (deselect with '-m \"not slow\"')",
-    "valid_from: marks tests as valid from a specific fork version",
     "valid_until: marks tests as valid until a specific fork version",
-    "valid_at: marks tests as valid only at a specific fork version",
-    "requires: marks tests as requiring one or more fork capabilities",
     "interop: integration tests for multiple leanSpec nodes",
     "num_validators: number of validators for interop test cluster",
 ]

src/lean_spec/forks/__init__.py

@@ -1,7 +1,5 @@
 """Multi-fork dispatch layer for leanSpec consensus specification."""
 
-from . import capabilities
-from .capabilities import SigScheme
 from .lstar.containers import (
     AggregatedAttestation,
     AggregatedAttestations,
@@ -48,7 +46,6 @@
     "ForkRegistry",
     "LstarSpec",
     "LstarStore",
-    "SigScheme",
     "SignedAggregatedAttestation",
     "SignedAttestation",
     "SignedBlock",
@@ -58,5 +55,4 @@
     "Store",
     "Validator",
     "Validators",
-    "capabilities",
 ]

src/lean_spec/forks/lstar/spec.py

@@ -43,7 +43,7 @@
     TypeTwoMultiSignature,
 )
 from lean_spec.subspecs.xmss.containers import PublicKey
-from lean_spec.subspecs.xmss.interface import TARGET_SIGNATURE_SCHEME, GeneralizedXmssScheme
+from lean_spec.subspecs.xmss.interface import TARGET_SIGNATURE_SCHEME
 from lean_spec.types import (
     ZERO_HASH,
     Boolean,
@@ -72,9 +72,6 @@ class LstarSpec(ForkProtocol):
 
     previous: ClassVar[type[ForkProtocol] | None] = None
 
-    # Capabilities advertised by this fork.
-    sig_scheme: ClassVar[GeneralizedXmssScheme] = TARGET_SIGNATURE_SCHEME
-
     state_class: type[State] = State
     block_class: type[Block] = Block
     block_body_class: type[BlockBody] = BlockBody
@@ -874,7 +871,6 @@ def verify_signatures(
         The block envelope holds one SSZ-encoded Type-2 proof binding
         every body attestation plus the proposer's signature over the
         block root.
-        The signing scheme is read from this fork's capability.
 
         Args:
             signed_block: The signed block whose merged proof is checked.
@@ -1109,7 +1105,7 @@ def on_gossip_attestation(
 
         This method:
 
-        1. Verifies the XMSS signature using this fork's capability
+        1. Verifies the XMSS signature
         2. Stores the signature when the node is in aggregator mode
 
         Subnet filtering happens at the p2p subscription layer — only
@@ -1148,7 +1144,7 @@ def on_gossip_attestation(
             )
             public_key = key_state.validators[validator_id].get_attestation_pubkey()
 
-            assert self.sig_scheme.verify(
+            assert TARGET_SIGNATURE_SCHEME.verify(
                 public_key, attestation_data.slot, hash_tree_root(attestation_data), signature
             ), "Signature verification failed"
 
@@ -1251,8 +1247,6 @@ def on_block(
         3. Processing attestations included in the block body (on-chain)
         4. Updating the forkchoice head
 
-        Signatures are verified using this fork's capability.
-
         Raises:
             AssertionError: If parent block/state not found in store.
         """