def blockchain_validity(chain):
"""
Tests the validity of the blockchain using the following rules
- The blockchain must begin with the genesis block
- The blockchain must be formatted correctly
"""
if chain[0] != Block.genesis():
raise Exception(
"The chain does not begin with the genesis block !!!")
for i in range(1, len(chain)):
block = chain[i]
last_block = chain[i - 1]
Block.block_validity(last_block, block)
def test_hash_validity(last_block, block):
block.hash = '0000000000000000000000000aabbccdd'
with pytest.raises(Exception, match="The block hash is invalid !!!"):
Block.block_validity(last_block, block)
def test_difficulty_interval(last_block, block):
block.difficulty = 10
block.hash = "0000000000000000000000000aabbccdd"
with pytest.raises(Exception, match="The block difficulty adjustment is not 1 !!!"):
Block.block_validity(last_block, block)
def test_proof_of_work(last_block, block):
block.hash = 'aabbccdd'
with pytest.raises(Exception, match="The proof of work requirement was not met !!!"):
Block.block_validity(last_block, block)
def test_valid_last_hash(last_block, block):
block.last_hash = "foo bar"
with pytest.raises(Exception, match="The last hash is invalid !!!"):
Block.block_validity(last_block, block)
def test_valid_block(last_block, block):
Block.block_validity(last_block, block)