logos-blockchain-specs/cryptarchia/test_ledger_state_update.py

109 lines
3.3 KiB
Python

from unittest import TestCase
import numpy as np
from .cryptarchia import (
Follower,
TimeConfig,
BlockHeader,
Config,
Coin,
LedgerState,
MockLeaderProof,
Slot,
Id,
)
def mk_genesis_state(initial_stake_distribution: list[Coin]) -> LedgerState:
return LedgerState(
block=bytes(32),
nonce=bytes(32),
total_stake=sum(c.value for c in initial_stake_distribution),
commitments={c.commitment() for c in initial_stake_distribution},
nullifiers=set(),
)
def mk_block(parent: Id, slot: int, coin: Coin, content=bytes(32)) -> BlockHeader:
from hashlib import sha256
return BlockHeader(
slot=Slot(slot),
parent=parent,
content_size=len(content),
content_id=sha256(content).digest(),
leader_proof=MockLeaderProof.from_coin(coin),
)
def config() -> Config:
return Config(
k=10,
active_slot_coeff=0.05,
time=TimeConfig(slots_per_epoch=1000, slot_duration=1, chain_start_time=0),
)
class TestLedgerStateUpdate(TestCase):
def test_ledger_state_prevents_coin_reuse(self):
leader_coin = Coin(pk=0, value=100)
genesis = mk_genesis_state([leader_coin])
follower = Follower(genesis, config())
block = mk_block(slot=0, parent=genesis.block, coin=leader_coin)
follower.on_block(block)
# Follower should have accepted the block
assert follower.local_chain.length() == 1
assert follower.local_chain.tip() == block
# Follower should have updated their ledger state to mark the leader coin as spent
assert follower.ledger_state.verify_unspent(leader_coin.nullifier()) == False
reuse_coin_block = mk_block(slot=1, parent=block.id, coin=leader_coin)
follower.on_block(block)
# Follower should *not* have accepted the block
assert follower.local_chain.length() == 1
assert follower.local_chain.tip() == block
def test_ledger_state_is_properly_updated_on_reorg(self):
coin_1 = Coin(pk=0, value=100)
coin_2 = Coin(pk=1, value=100)
coin_3 = Coin(pk=1, value=100)
genesis = mk_genesis_state([coin_1, coin_2, coin_3])
follower = Follower(genesis, config())
# 1) coin_1 & coin_2 both concurrently win slot 0
block_1 = mk_block(parent=genesis.block, slot=0, coin=coin_1)
block_2 = mk_block(parent=genesis.block, slot=0, coin=coin_2)
# 2) follower sees block 1 first
follower.on_block(block_1)
assert follower.tip_id() == block_1.id()
assert not follower.ledger_state.verify_unspent(coin_1.nullifier())
# 3) then sees block 2, but sticks with block_1 as the tip
follower.on_block(block_2)
assert follower.tip_id() == block_1.id()
assert len(follower.forks) == 1, f"{len(follower.forks)}"
# 4) then coin_3 wins slot 1 and chooses to extend from block_2
block_3 = mk_block(parent=block_2.id(), slot=0, coin=coin_3)
follower.on_block(block_3)
# the follower should have switched over to the block_2 fork
assert follower.tip_id() == block_3.id()
# and the original coin_1 should now be removed from the spent pool
assert follower.ledger_state.verify_unspent(coin_1.nullifier())