def test_finality_rule_2(spec, state): # get past first two epochs that finality does not run on next_epoch(spec, state) apply_empty_block(spec, state) next_epoch(spec, state) apply_empty_block(spec, state) yield 'pre', state blocks = [] for epoch in range(3): if epoch == 0: prev_state, new_blocks, state = next_epoch_with_attestations(spec, state, True, False) check_finality(spec, state, prev_state, True, False, False) elif epoch == 1: prev_state, new_blocks, state = next_epoch_with_attestations(spec, state, False, False) check_finality(spec, state, prev_state, False, True, False) elif epoch == 2: prev_state, new_blocks, state = next_epoch_with_attestations(spec, state, False, True) # finalized by rule 2 check_finality(spec, state, prev_state, True, False, True) assert state.finalized_checkpoint == prev_state.previous_justified_checkpoint blocks += new_blocks yield 'blocks', blocks yield 'post', state
def test_finality_rule_3(spec, state): """ Test scenario described here https://github.com/ethereum/eth2.0-specs/issues/611#issuecomment-463612892 """ # get past first two epochs that finality does not run on next_epoch(spec, state) apply_empty_block(spec, state) next_epoch(spec, state) apply_empty_block(spec, state) yield 'pre', state blocks = [] prev_state, new_blocks, state = next_epoch_with_attestations( spec, state, True, False) blocks += new_blocks check_finality(spec, state, prev_state, True, False, False) # In epoch N, JE is set to N, prev JE is set to N-1 prev_state, new_blocks, state = next_epoch_with_attestations( spec, state, True, False) blocks += new_blocks check_finality(spec, state, prev_state, True, True, True) # In epoch N+1, JE is N, prev JE is N-1, and not enough messages get in to do anything prev_state, new_blocks, state = next_epoch_with_attestations( spec, state, False, False) blocks += new_blocks check_finality(spec, state, prev_state, False, True, False) # In epoch N+2, JE is N, prev JE is N, and enough messages from the previous epoch get in to justify N+1. # N+1 now becomes the JE. Not enough messages from epoch N+2 itself get in to justify N+2 prev_state, new_blocks, state = next_epoch_with_attestations( spec, state, False, True) blocks += new_blocks # rule 2 check_finality(spec, state, prev_state, True, False, True) # In epoch N+3, LJE is N+1, prev LJE is N, and enough messages get in to justify epochs N+2 and N+3. prev_state, new_blocks, state = next_epoch_with_attestations( spec, state, True, True) blocks += new_blocks # rule 3 check_finality(spec, state, prev_state, True, True, True) assert state.finalized_checkpoint == prev_state.current_justified_checkpoint yield 'blocks', blocks yield 'post', state
def apply_next_epoch_with_attestations(spec, state, store): _, new_blocks, post_state = next_epoch_with_attestations( spec, state, True, False) for block in new_blocks: block_root = signing_root(block) store.blocks[block_root] = block store.block_states[block_root] = post_state last_block = block spec.on_tick(store, store.time + state.slot * spec.SECONDS_PER_SLOT) return post_state, store, last_block
def test_finality_no_updates_at_genesis(spec, state): assert spec.get_current_epoch(state) == spec.GENESIS_EPOCH yield 'pre', state blocks = [] for epoch in range(2): prev_state, new_blocks, state = next_epoch_with_attestations(spec, state, True, False) blocks += new_blocks # justification/finalization skipped at GENESIS_EPOCH if epoch == 0: check_finality(spec, state, prev_state, False, False, False) # justification/finalization skipped at GENESIS_EPOCH + 1 elif epoch == 1: check_finality(spec, state, prev_state, False, False, False) yield 'blocks', blocks yield 'post', state
def test_finality_rule_4(spec, state): # get past first two epochs that finality does not run on next_epoch(spec, state) apply_empty_block(spec, state) next_epoch(spec, state) apply_empty_block(spec, state) yield 'pre', state blocks = [] for epoch in range(2): prev_state, new_blocks, state = next_epoch_with_attestations(spec, state, True, False) blocks += new_blocks if epoch == 0: check_finality(spec, state, prev_state, True, False, False) elif epoch == 1: # rule 4 of finality check_finality(spec, state, prev_state, True, True, True) assert state.finalized_checkpoint == prev_state.current_justified_checkpoint yield 'blocks', blocks yield 'post', state
def test_filtered_block_tree(spec, state): # Initialization genesis_state_root = state.hash_tree_root() store = spec.get_genesis_store(state) genesis_block = spec.BeaconBlock(state_root=genesis_state_root) # transition state past initial couple of epochs next_epoch(spec, state) next_epoch(spec, state) assert spec.get_head(store) == spec.hash_tree_root(genesis_block) # fill in attestations for entire epoch, justifying the recent epoch prev_state, signed_blocks, state = next_epoch_with_attestations( spec, state, True, False) attestations = [ attestation for signed_block in signed_blocks for attestation in signed_block.message.body.attestations ] assert state.current_justified_checkpoint.epoch > prev_state.current_justified_checkpoint.epoch # tick time forward and add blocks and attestations to store current_time = state.slot * spec.SECONDS_PER_SLOT + store.genesis_time spec.on_tick(store, current_time) for signed_block in signed_blocks: spec.on_block(store, signed_block) for attestation in attestations: spec.on_attestation(store, attestation) assert store.justified_checkpoint == state.current_justified_checkpoint # the last block in the branch should be the head expected_head_root = spec.hash_tree_root(signed_blocks[-1].message) assert spec.get_head(store) == expected_head_root # # create branch containing the justified block but not containing enough on # chain votes to justify that block # # build a chain without attestations off of previous justified block non_viable_state = store.block_states[ store.justified_checkpoint.root].copy() # ensure that next wave of votes are for future epoch next_epoch(spec, non_viable_state) next_epoch(spec, non_viable_state) next_epoch(spec, non_viable_state) assert spec.get_current_epoch( non_viable_state) > store.justified_checkpoint.epoch # create rogue block that will be attested to in this non-viable branch rogue_block = build_empty_block_for_next_slot(spec, non_viable_state) signed_rogue_block = state_transition_and_sign_block( spec, non_viable_state, rogue_block) # create an epoch's worth of attestations for the rogue block next_epoch(spec, non_viable_state) attestations = [] for i in range(spec.SLOTS_PER_EPOCH): slot = rogue_block.slot + i for index in range( spec.get_committee_count_at_slot(non_viable_state, slot)): attestation = get_valid_attestation(spec, non_viable_state, rogue_block.slot + i, index) attestations.append(attestation) # tick time forward to be able to include up to the latest attestation current_time = (attestations[-1].data.slot + 1) * spec.SECONDS_PER_SLOT + store.genesis_time spec.on_tick(store, current_time) # include rogue block and associated attestations in the store spec.on_block(store, signed_rogue_block) for attestation in attestations: spec.on_attestation(store, attestation) # ensure that get_head still returns the head from the previous branch assert spec.get_head(store) == expected_head_root