describe("rotate",
{
    ee <- expect_equal

    test_that("rotate.Deque works correctly", {
        d <- deque(1, 2, 3, 4)
        ee(rotate(d), deque(4, 1, 2, 3))
        ee(rotate(d, 2), deque(3, 4, 1, 2))
        ee(rotate(d, -1), deque(2, 3, 4, 1))
    })

    test_that("ref_rotate.Deque modifies in place", {
        d <- deque(1, 2, 3, 4)

        # by reference
        ref_rotate(d)
        ee(d, deque(4, 1, 2, 3))

        ref_rotate(d, -1)
        ee(d, deque(1, 2, 3, 4))
    })
})