fix: cleanups from comments on PR leanEthereum#76

Author: fselmo

packages/tests/src/lean_spec_tests/pytest_plugins/filler.py

@@ -1,6 +1,10 @@
 """Pytest plugin for generating consensus test fixtures."""
 
 import json
+import shutil
+import sys
+import textwrap
+from collections import defaultdict
 from pathlib import Path
 from typing import Any, List
 
@@ -75,8 +79,6 @@ def write_fixtures(self) -> None:
         Groups fixtures by their base test function (stripping parameters)
         so all parametrized variations end up in the same JSON file.
         """
-        from collections import defaultdict
-
         # Group fixtures by (file_path, base_function_name, format)
         grouped: dict[tuple[str, str, str], list[tuple[str, Any, str]]] = defaultdict(list)
 
@@ -154,9 +156,6 @@ def pytest_addoption(parser: pytest.Parser) -> None:
 
 def pytest_configure(config: pytest.Config) -> None:
     """Setup fixture generation session."""
-    import sys
-    import textwrap
-
     # Register fork validity markers
     config.addinivalue_line(
         "markers",
@@ -227,8 +226,6 @@ def pytest_configure(config: pytest.Config) -> None:
                 returncode=pytest.ExitCode.USAGE_ERROR,
             )
         # Clean if requested
-        import shutil
-
         shutil.rmtree(output_dir)
 
     # Create output directory

packages/tests/src/lean_spec_tests/test_fixtures/fork_choice.py

@@ -9,6 +9,9 @@
 from lean_spec.subspecs.containers.block.types import Attestations
 from lean_spec.subspecs.containers.slot import Slot
 from lean_spec.subspecs.containers.state.state import State
+from lean_spec.subspecs.forkchoice import Store
+from lean_spec.subspecs.ssz import hash_tree_root
+from lean_spec.types import Uint64
 
 from ..test_types import AttestationStep, BlockStep, ForkChoiceStep, TickStep
 from .base import BaseConsensusFixture
@@ -64,8 +67,6 @@ def set_anchor_block_default(self) -> "ForkChoiceTest":
         anchor_state itself.
         """
         if self.anchor_block is None:
-            from lean_spec.subspecs.ssz.hash import hash_tree_root
-
             self.anchor_block = Block(
                 slot=self.anchor_state.latest_block_header.slot,
                 proposer_index=self.anchor_state.latest_block_header.proposer_index,
@@ -94,8 +95,6 @@ def make_fixture(self) -> "ForkChoiceTest":
         AssertionError
             If any step fails unexpectedly or checks don't match Store state.
         """
-        from lean_spec.subspecs.forkchoice.store import Store
-
         # Initialize Store from anchor
         # anchor_block is guaranteed to be set by the validator
         assert self.anchor_block is not None, "anchor_block must be set"
@@ -109,15 +108,10 @@ def make_fixture(self) -> "ForkChoiceTest":
             try:
                 if isinstance(step, TickStep):
                     # Advance time
-                    from lean_spec.types import Uint64
-
                     store.advance_time(Uint64(step.time), has_proposal=False)
 
                 elif isinstance(step, BlockStep):
                     # Automatically advance time to block's slot before processing
-                    # (Like consensus-specs' tick_and_add_block helper)
-                    from lean_spec.types import Uint64
-
                     block = step.block.message
                     block_time = store.config.genesis_time + block.slot * Uint64(SECONDS_PER_SLOT)
 

src/lean_spec/subspecs/forkchoice/helpers.py

@@ -55,15 +55,13 @@ def get_fork_choice_head(
                 children_map.setdefault(block.parent_root, []).append(block_hash)
 
     # Walk down tree, choosing child with most votes (tiebreak by lexicographic hash)
-    # Matches consensus-specs: (weight, root) for tie-breaking
     current = root
     while True:
         children = children_map.get(current, [])
         if not children:
             return current
 
         # Choose best child: most votes, then lexicographically highest hash
-        # Note: Removed slot tiebreaker to match consensus-specs
         current = max(children, key=lambda x: (vote_weights.get(x, 0), x))
 
 

src/lean_spec/subspecs/forkchoice/store.py

@@ -102,7 +102,7 @@ class method acts as a factory for creating a new Store instance.
         anchor_root = hash_tree_root(anchor_block)
         anchor_slot = anchor_block.slot
 
-        # Create checkpoint from anchor block (matches consensus-specs)
+        # Create checkpoint from anchor block
         # The anchor block becomes the initial justified and finalized checkpoint
         anchor_checkpoint = Checkpoint(root=anchor_root, slot=anchor_slot)