library(igraph)
test_that("layout_spectral works", {
  g <- igraph::make_graph(~ a - -b - -c - -d:e:f)

  expect_is(layout_with_eigen(g, type = "adjacency", ev = "largest"), "matrix")
  expect_is(layout_with_eigen(g, type = "adjacency", ev = "smallest"), "matrix")
  expect_is(layout_with_eigen(g, type = "laplacian", ev = "largest"), "matrix")
  expect_is(layout_with_eigen(g, type = "laplacian", ev = "smallest"), "matrix")

  expect_warning(layout_with_eigen(igraph::as.directed(g)))
  expect_error(layout_with_eigen(igraph::graph.empty(10, directed = FALSE)))

  expect_error(layout_with_eigen(g, type = "laplacian", ev = "middlest"))
  expect_error(layout_with_eigen(g, type = "random"))
  expect_error(layout_with_eigen(1))
})