def test_attributes_from_environment_variables():
""" Test that the default cluster environment takes the attributes from the environment variables. """
env = LightningEnvironment()
assert env.master_address() == "1.2.3.4"
assert env.master_port() == 500
assert env.world_size() is None
assert env.local_rank() == 2
assert env.node_rank() == 3
def test_default_attributes():
""" Test the default attributes when no environment variables are set. """
env = LightningEnvironment()
assert not env.creates_children()
assert env.master_address() == "127.0.0.1"
assert isinstance(env.master_port(), int)
assert env.world_size() == 1
assert env.local_rank() == 0
assert env.node_rank() == 0