test(fc): add test for head-selection#590
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tcoratger merged 5 commits intoleanEthereum:mainfrom Apr 11, 2026
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@akronim26 Can you solve conflicts? |
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…tion - Add intermediate StoreChecks on every block (justified/finalized progression visible step by step) - Add head_root_label="block_5" to pin exact head identity - Add latest_justified_slot=Slot(4) to explain the mechanism: LMD-GHOST starts from the justified root (block_4), making the dead fork unreachable - Rewrite docstring: ASCII diagram of the fork, bullet-point justification chain, clear explanation of the unreachability mechanism - Rewrite inline comments: section headers, concrete finalization arithmetic, structured labels Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
…eight Rewrite the test to actually prove finalization constrains fork choice. The previous version had a zero-weight dead fork that would lose purely on weight comparison, making the test pass for the wrong reason. New design: 8 validators. - Canonical chain (V0-V5, 6/8): justifies slots 1-4, finalizes slot 3 - Dead fork from block_2 with 2 blocks (dead_6, dead_7) - dead_7 carries attestations from V3-V7 (5/8) targeting dead_6 - V3-V5's dead fork attestations (slot 7) override their canonical ones (slot 5), giving the dead fork MORE total weight - 5 attesters stay below 2/3 threshold (3*5=15 < 2*8=16), so no justification on the dead fork Result: dead fork has weight 5 vs canonical's 0 from the justified root, yet the head stays at block_5 because LMD-GHOST starts from block_4 (justified root) and the dead fork branches from block_2 (unreachable). Also fix framework bug: StoreChecks.validate_against_store() was missing the handler for latest_finalized_root_label. The field was declared on the model but silently ignored during validation. Added the handler following the same pattern as latest_justified_root_label. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
tcoratger
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Apr 11, 2026
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🗒️ Description
This PR introduces
test_fork_from_before_finalization_not_consideredto the fork choice test suite to verify a critical LMD-GHOST safety property: blocks belonging to a fork that originates before the latest finalized slot are ignored by the head selection.🔗 Related Issues or PRs
Closes #582
✅ Checklist
toxchecks to avoid unnecessary CI fails:uvx tox