def test_init(self):
with self.subTest("An empty new chain creates a genesis block"):
self.assertEqual(Block.objects.count(), 0)
self.assertEqual(BlockChain().head, Block.objects.first())
self.assertEqual(Block.objects.count(), 1)
with self.subTest("An existing chain doesn't create more blocks"):
BlockChain()
self.assertEqual(Block.objects.count(), 1)
BlockChain()
self.assertEqual(Block.objects.count(), 1)
def post(self, request):
generator = serializers.deserialize('json', request.body)
chain = [block for block in generator]
chain_queryset = BlockChain().fork_choice(chain)
if self.unseen_chain(chain_queryset):
Gossip.all_about_it(chain)
return HttpResponse("Accepted new blocks.", status=200)
else:
return HttpResponse("Rejected blocks. Chain has been seen.",
status=202)
def test_blockchain_view(self):
with self.subTest("No blocks exist"):
response = self.client.get('/blockchain')
self.assertEqual(response.status_code, 200)
self.assertTemplateUsed(response, 'blockchain.html')
self.assertContains(response, "This must be a crap coin...")
with self.subTest("With many blocks, can view as a list"):
chain = BlockChain()
response = self.client.get('/blockchain')
self.assertEqual(response.status_code, 200)
self.assertTemplateUsed(response, 'blockchain.html')
self.assertContains(response, chain.head.hash_id)
def post(self, request):
""" Used for internal transactions where this node creates a
transaction. """
form = BlockCreateForm(request.POST)
if form.is_valid():
block = Block(
payee=form.data['payee'],
payer=form.data['payer'],
amount=form.data['amount'],
)
try:
chain = BlockChain().add_block(block)
Gossip.all_about_it(chain)
return redirect('blockchain')
except ValueError:
return HttpResponse("Invalid form--did you include all fields?")
def test_is_valid_block(self):
with self.subTest("True with valid pow solution"):
chain = BlockChain()
transaction = Faker().sha256()
new_block = chain.mint(transaction)
chain.is_valid_block(new_block)
with self.subTest("False with invalid pow solution"):
chain = BlockChain()
self.assertEqual(chain.is_valid_pow("fake_hash"))
with self.subTest("True if transaction output <= input"):
raise
with self.subTest("False if transaction output > input"):
raise
with self.subTest("False if doublespend"):
raise
def __init__(self):
chain = BlockChain()
for _ in range(0, 10):
content = Faker().sha256()
chain.mint(content)
return chain
def unseen_chain(self, chain):
current_head = BlockChain().last().hash_id
new_chain_head = chain.order_by('-number').first().hash_id
return current_head != new_chain_head
def test_mint(self):
with self.subTest("Can mine new blocks"):
transaction = Faker().sha256()
BlockChain().mint(transaction)
self.assertEqual(Block.objects.count(), 2)