test_that("get roots directed", {
  graph <- graph_builder() |>
    add_path(c("A", "B", "C")) |>
    add_path(c("A", "D", "C")) |>
    add_path(c("Z", "B", "C")) |>
    build_directed()


  expect_equal(
    as.character(get_all_roots(graph)),
    c("A", "Z")
  )
  expect_equal(
    as.character(get_roots_over(graph, "D")),
    c("A")
  )
})

test_that("get leaves directed", {
  graph <- graph_builder() |>
    add_path(c("A", "B", "C")) |>
    add_path(c("A", "D", "C")) |>
    add_path(c("Z", "B", "C")) |>
    add_path(c("Z", "B", "H")) |>
    build_directed()

  expect_equal(
    as.character(get_all_leaves(graph)),
    c("C", "H")
  )
  expect_equal(
    as.character(get_leaves_under(graph, "D")),
    c("C")
  )
})

test_that("get roots acyclic", {
  graph <- graph_builder() |>
    add_path(c("A", "B", "C")) |>
    add_path(c("A", "D", "C")) |>
    add_path(c("Z", "B", "C")) |>
    build_acyclic()


  expect_equal(
    as.character(get_all_roots(graph)),
    c("A", "Z")
  )
  expect_equal(
    as.character(get_roots_over(graph, "D")),
    c("A")
  )
})

test_that("get leaves acyclic", {
  graph <- graph_builder() |>
    add_path(c("A", "B", "C")) |>
    add_path(c("A", "D", "C")) |>
    add_path(c("Z", "B", "C")) |>
    add_path(c("Z", "B", "H")) |>
    build_acyclic()

  expect_equal(
    as.character(get_all_leaves(graph)),
    c("C", "H")
  )
  expect_equal(
    as.character(get_leaves_under(graph, "D")),
    c("C")
  )
})