eth2.0-specs/test_libs/pyspec/eth2spec/test/test_finality.py

222 lines
8.1 KiB
Python

from copy import deepcopy
from eth2spec.test.context import spec_state_test, never_bls, with_all_phases
from eth2spec.test.helpers.state import next_epoch, state_transition_and_sign_block
from eth2spec.test.helpers.block import build_empty_block_for_next_slot, apply_empty_block
from eth2spec.test.helpers.attestations import get_valid_attestation
def check_finality(spec,
state,
prev_state,
current_justified_changed,
previous_justified_changed,
finalized_changed):
if current_justified_changed:
assert state.current_justified_checkpoint.epoch > prev_state.current_justified_checkpoint.epoch
assert state.current_justified_checkpoint.root != prev_state.current_justified_checkpoint.root
else:
assert state.current_justified_checkpoint == prev_state.current_justified_checkpoint
if previous_justified_changed:
assert state.previous_justified_checkpoint.epoch > prev_state.previous_justified_checkpoint.epoch
assert state.previous_justified_checkpoint.root != prev_state.previous_justified_checkpoint.root
else:
assert state.previous_justified_checkpoint == prev_state.previous_justified_checkpoint
if finalized_changed:
assert state.finalized_checkpoint.epoch > prev_state.finalized_checkpoint.epoch
assert state.finalized_checkpoint.root != prev_state.finalized_checkpoint.root
else:
assert state.finalized_checkpoint == prev_state.finalized_checkpoint
def next_epoch_with_attestations(spec,
state,
fill_cur_epoch,
fill_prev_epoch):
assert state.slot % spec.SLOTS_PER_EPOCH == 0
post_state = deepcopy(state)
blocks = []
for _ in range(spec.SLOTS_PER_EPOCH):
block = build_empty_block_for_next_slot(spec, post_state)
if fill_cur_epoch and post_state.slot >= spec.MIN_ATTESTATION_INCLUSION_DELAY:
slot_to_attest = post_state.slot - spec.MIN_ATTESTATION_INCLUSION_DELAY + 1
if slot_to_attest >= spec.compute_start_slot_of_epoch(spec.get_current_epoch(post_state)):
cur_attestation = get_valid_attestation(spec, post_state, slot_to_attest)
block.body.attestations.append(cur_attestation)
if fill_prev_epoch:
slot_to_attest = post_state.slot - spec.SLOTS_PER_EPOCH + 1
prev_attestation = get_valid_attestation(spec, post_state, slot_to_attest)
block.body.attestations.append(prev_attestation)
state_transition_and_sign_block(spec, post_state, block)
blocks.append(block)
return state, blocks, post_state
@with_all_phases
@never_bls
@spec_state_test
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
@with_all_phases
@never_bls
@spec_state_test
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
@with_all_phases
@never_bls
@spec_state_test
def test_finality_rule_1(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):
prev_state, new_blocks, state = next_epoch_with_attestations(spec, state, False, True)
blocks += new_blocks
if epoch == 0:
check_finality(spec, state, prev_state, True, False, False)
elif epoch == 1:
check_finality(spec, state, prev_state, True, True, False)
elif epoch == 2:
# finalized by rule 1
check_finality(spec, state, prev_state, True, True, True)
assert state.finalized_checkpoint == prev_state.previous_justified_checkpoint
yield 'blocks', blocks
yield 'post', state
@with_all_phases
@never_bls
@spec_state_test
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
@with_all_phases
@never_bls
@spec_state_test
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