def test_LIFO_read():
buf = Buffer(yield_next="newest")
buf.write(["1", "2", "3"])
assert len(buf.data) == 3
assert buf.read() == ["3"]
assert buf.read() == ["2"]
assert buf.read() == ["1"]
assert len(buf.data) == 0
def test_FIFO_read():
buf = Buffer()
buf.write(["1", "2", "3"])
assert len(buf.data) == 3
assert buf.read() == ["1"]
assert buf.read() == ["2"]
assert buf.read() == ["3"]
assert len(buf.data) == 0
def test_read_empty():
buf = Buffer()
assert buf.read() == []
assert len(buf.data) == 0