refactor: move generate_pre_state to consensus_testing package root (#550)

The function was misplaced in test_types/, which is otherwise exclusively
Pydantic model definitions. Move it to consensus_testing/genesis.py,
alongside keys.py which it directly depends on.

Also improves the function:
- Replace assert with ValueError for input validation
- Clean up docstring (remove default value restating)
- Rename validator_list to validators

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: tcoratger

packages/testing/src/consensus_testing/__init__.py

@@ -3,6 +3,7 @@
 from typing import Type
 
 from . import forks
+from .genesis import generate_pre_state
 from .test_fixtures import (
     BaseConsensusFixture,
     ForkChoiceTest,
@@ -25,7 +26,6 @@
     StateExpectation,
     StoreChecks,
     TickStep,
-    generate_pre_state,
 )
 
 StateTransitionTestFiller = Type[StateTransitionTest]

…/consensus_testing/test_types/genesis.py …testing/src/consensus_testing/genesis.pypackages/testing/src/consensus_testing/test_types/genesis.py renamed to packages/testing/src/consensus_testing/genesis.py packages/testing/src/consensus_testing/test_types/genesis.py renamed to packages/testing/src/consensus_testing/genesis.py

@@ -4,7 +4,7 @@
 from lean_spec.subspecs.containers.validator import Validator, ValidatorIndex
 from lean_spec.types import Bytes52, Uint64
 
-from ..keys import XmssKeyManager
+from .keys import XmssKeyManager
 
 _DEFAULT_GENESIS_TIME = Uint64(0)
 
@@ -13,37 +13,33 @@ def generate_pre_state(
     genesis_time: Uint64 = _DEFAULT_GENESIS_TIME,
     num_validators: int = 4,
 ) -> State:
-    """
-    Generate a default pre-state for consensus tests.
+    """Generate a default pre-state for consensus tests.
 
     Args:
-        genesis_time: The genesis timestamp (defaults to Uint64(0)).
-        num_validators: Number of validators (defaults to 4).
+        genesis_time: The genesis timestamp.
+        num_validators: Number of validators to include.
 
     Returns:
         A properly initialized consensus state.
     """
     key_manager = XmssKeyManager.shared()
-    available_keys = len(key_manager)
 
-    assert num_validators <= available_keys, (
-        f"Not enough keys to generate state. "
-        f"Expecting a minimum of {num_validators} validators "
-        f"but the key manager has only {available_keys} keys"
-    )
+    if num_validators > len(key_manager):
+        raise ValueError(
+            f"Not enough keys: need {num_validators} validators "
+            f"but the key manager has only {len(key_manager)} keys"
+        )
 
-    validator_list = []
+    validators = []
     for i in range(num_validators):
         idx = ValidatorIndex(i)
         attestation_pubkey, proposal_pubkey = key_manager.get_public_keys(idx)
-        validator_list.append(
+        validators.append(
             Validator(
                 attestation_pubkey=Bytes52(attestation_pubkey.encode_bytes()),
                 proposal_pubkey=Bytes52(proposal_pubkey.encode_bytes()),
                 index=idx,
             )
         )
 
-    return State.generate_genesis(
-        genesis_time=genesis_time, validators=Validators(data=validator_list)
-    )
+    return State.generate_genesis(genesis_time=genesis_time, validators=Validators(data=validators))

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

@@ -2,7 +2,6 @@
 
 from .aggregated_attestation_spec import AggregatedAttestationSpec
 from .block_spec import BlockSpec
-from .genesis import generate_pre_state
 from .gossip_aggregated_attestation_spec import GossipAggregatedAttestationSpec
 from .gossip_attestation_spec import GossipAttestationSpec
 from .state_expectation import StateExpectation
@@ -31,5 +30,4 @@
     "AttestationStep",
     "ForkChoiceStep",
     "GossipAggregatedAttestationStep",
-    "generate_pre_state",
 ]