def test_replace_chain():
"""Test replace a chain"""
# Generate the genesis block
block = Block.genesis_block(timestamp=datetime(2000, 1, 1), difficulty=4, mining=True)
# Generate a old chain
old_chain = BlockChain(block)
# Generate longer chain
blockchain = BlockChain(block)
# Cannot be replace the chain
assert old_chain.replace_chain(blockchain) is False
# Add new block
assert blockchain.add_candidate(None, timestamp=datetime(2000, 1, 2))
assert blockchain.candidate_proof(4)
# Replace the chain
assert old_chain.replace_chain(blockchain)
# Check the chain values
assert old_chain.num_blocks == 2
assert old_chain.candidate_block is None
def test_validate_blockchain():
"""Test BlockChain validation"""
block = Block.genesis_block(timestamp=datetime(2000, 1, 1), difficulty=4, mining=True)
blockchain = BlockChain(block)
# Add a new candidate
assert blockchain.add_candidate(None, timestamp=datetime(2000, 1, 2))
assert blockchain.candidate_proof(4)
assert blockchain.is_valid
# Alter the index
blockchain.chain[1].index = 2
assert blockchain.chain[1].is_valid is False
assert blockchain.is_valid is False
# Mining new id
blockchain.chain[1].mining()
assert blockchain.chain[1].is_valid
assert blockchain.is_valid is False
# Change the block
blockchain.chain[1] = block
assert blockchain.is_valid is False
def test_add_candidates_prof():
"""Test to update the proof to a candidate"""
block = Block.genesis_block(timestamp=datetime(2000, 1, 1), difficulty=4, mining=True)
blockchain = BlockChain(block)
# Add a new candidate
assert blockchain.add_candidate(None, timestamp=datetime(2000, 1, 2))
# Add proof to candidate
assert blockchain.candidate_proof(3) is False
assert blockchain.candidate_proof(4)
# Add an empty candidate
assert blockchain.add_candidate(None)
# Add an invalid candidate (same date)
assert blockchain.add_candidate(None, timestamp=datetime(2000, 1, 1)) is False
assert blockchain.candidate_proof(3) is False
assert blockchain.candidate_proof(4) is False