class BlockChainTests(unittest.TestCase):
def setUp(self):
self.chain = BlockChain()
def test_is_valid_genesis_correctness(self):
genesis = self.chain.get_latest_block()
fake_genesis = Block(
0,
hashlib.sha256(
str(round(time.time() * 1000)).encode('utf-8') +
b"The Genesis block"), None, int(round(time.time() * 1000)),
"The Genesis block")
self.assertTrue(self.chain.is_valid_genesis(genesis))
self.assertFalse(self.chain.is_valid_genesis(fake_genesis))
def test_is_valid_new_block_correctness(self):
timestamp = str(round(time.time() * 1000))
previous_block = self.chain.get_latest_block()
correct_block = Block(
1,
self.chain.calculate_hash(1, previous_block.hash, timestamp,
"The correct block"),
self.chain.get_latest_block().hash, int(round(time.time() * 1000)),
"The correct block")
incorrect_index = Block(
2,
self.chain.calculate_hash(2, previous_block.hash, timestamp,
"The incorrect block"),
self.chain.get_latest_block().hash, int(round(time.time() * 1000)),
"The incorrect block")
incorrect_hash = Block(
1,
self.chain.calculate_hash(
1,
hashlib.sha256('hi'.encode('utf-8')).hexdigest(), timestamp,
"The correct block"),
self.chain.get_latest_block().hash, int(round(time.time() * 1000)),
"The correct block")
self.assertTrue(
self.chain.is_valid_new_block(correct_block,
self.chain.get_latest_block()))
self.assertFalse(
self.chain.is_valid_new_block(incorrect_index,
self.chain.get_latest_block()))
self.assertFalse(
self.chain.is_valid_new_block(incorrect_hash,
self.chain.get_latest_block()))
def test_generate_next_block_correctness(self):
next_block = self.chain.generate_next_block('new data')
previous_block = self.chain.get_latest_block()
self.assertEqual(next_block.data, 'new data')
self.assertEqual(next_block.index, previous_block.index + 1)
self.assertEqual(
next_block.hash,
self.chain.calculate_hash(next_block.index, previous_block.hash,
next_block.timestamp, next_block.data))
def test_adding_correct_block(self):
next_block = self.chain.generate_next_block('new data')
self.chain.add_block(next_block)
latest_block = self.chain.get_latest_block()
self.assertEqual(len(self.chain), 2)
self.assertEqual(latest_block.index, next_block.index)
self.assertEqual(latest_block.hash, next_block.hash)
self.assertEqual(latest_block.data, next_block.data)
self.assertEqual(latest_block.timestamp, next_block.timestamp)
self.assertEqual(latest_block.previous_hash, next_block.previous_hash)
def test_adding_incorrect_block(self):
next_block = self.chain.generate_next_block('new data')
self.chain.add_block(next_block)
incorrect_block = Block(
2,
hashlib.sha256('wrong'.encode('utf-8')).hexdigest(),
next_block.hash, int(round(time.time() * 1000)),
"Not correct block")
self.chain.add_block(incorrect_block)
self.assertEqual(len(self.chain), 2)
verbose=True) else "Blockchain invalid"
def _create_validator_chain(self):
'''
Create a chain with the same genesis block. Blocks from the test chain will be added to this chain by verifying the validity of the chain.
'''
self.validator_chain_ = BlockChain(
chain=[self.blockchain_.genesis_block])
#################
### TEST CODE ###
#################
if __name__ == '__main__':
# ----- Create the blockchain and add the genesis block
blockchain = BlockChain()
num_of_blocks_to_add = 20
# ----- Gernerate a block chain by adding blocks to the chain
for i in range(0, num_of_blocks_to_add):
data = "Hey! I'm block " + str(blockchain.latest_block.index + 1)
blockchain.generate_next_block(data)
# ----- validate the blockchain
BlockChainTester(blockchain).validate()
