from plugins.host_agent.agent import RingBuffer


def test_ring_buffer_preserves_order():
    rb = RingBuffer(maxlen=3)
    rb.push(1); rb.push(2); rb.push(3)
    assert list(rb.drain()) == [1, 2, 3]
    assert len(rb) == 0


def test_ring_buffer_drops_oldest_when_full():
    rb = RingBuffer(maxlen=3)
    for v in (1, 2, 3, 4, 5):
        rb.push(v)
    assert list(rb.drain()) == [3, 4, 5]


def test_ring_buffer_drain_clears_and_is_atomic():
    rb = RingBuffer(maxlen=5)
    rb.push("a"); rb.push("b")
    out = list(rb.drain())
    rb.push("c")
    assert out == ["a", "b"]
    assert list(rb.drain()) == ["c"]