def test_slowly_mined_block():
    last_block = Block.mine_block(Block.genesis(), 'bar')

    time.sleep(MINE_RATE / SECONDS)

    mined_block = Block.mine_block(last_block, 'bar')

    assert mined_block.difficulty == last_block.difficulty - 1
def test_mine_block():
    last_block = Block.genesis()
    data = 'test-data'
    block = Block.mine_block(last_block, data)

    assert isinstance(block, Block)
    assert block.data == data
    assert block.last_hash == last_block.hash
    assert hex_to_binary(
        block.hash)[0:block.difficulty] == '0' * block.difficulty
def test_mined_block_difficulty_limits_at_1():
    last_block = Block(time.time_ns(), 'test_last_hash', 'test_hash',
                       'test_data', 1, 0)

    time.sleep(MINE_RATE / SECONDS)
    mined_block = Block.mine_block(last_block, 'bar')

    assert mined_block.difficulty == 1

    @pytest.fixture
    def last_block():
        return Block.genesis()

    @pytest.fixture
    def block(last_block):
        return Block.mine_block(last_block, 'test_data')

    def test_is_valid_block(last_block, block):
        Block.is_valid_block(last_block, block)

    def test_is_valid_block_bad_last_hash(last_block, block):
        block.last_hash = 'evil_last_hash'

        with pytest.raises(Exception, match='last_hash must be correct'):
            Block.is_valid_block(last_block, block)

    def test_is_valid_block_bad_proof_of_work(last_block, block):
        block.hash = 'fff'

        with pytest.raises(Exception,
                           match='proof of work requirement was not met'):
            Block.is_valid_block(last_block, block)

    def test_is_valid_block_jumped_difficulty(last_block, block):
        jumped_difficulty = 10
        block.difficulty = jumped_difficulty
        block.hash = f'{"0" * jumped_difficulty}111abc'

        with pytest.raises(Exception,
                           match='difficulty must only adjust by 1'):
            Block.is_valid_block(last_block, block)

    def test_is_valid_block_bad_block_hash(last_block, block):
        block.hash = '0000000000000000bbbabc'

        with pytest.raises(Exception, match='block hash must be correct'):
            Block.is_valid_block(last_block, block)
 def block(last_block):
     return Block.mine_block(last_block, 'test_data')
def test_quickly_mined_block():
    last_block = Block.mine_block(Block.genesis(), 'foo')
    mined_block = Block.mine_block(last_block, 'bar')

    assert mined_block.difficulty == last_block.difficulty + 1