test_that("elementary polygons get merged", {
  # two connected polygons get merged
  z <- matrix(c(0, 0, 1, 1, 1, 1), ncol = 3, nrow = 2, byrow = TRUE)
  out <- isobands(x = 1:3, y = 2:1, z, levels_low = 0.5, levels_high = 1.5)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(3.0, 2.0, 1.0, 1.0, 2.0, 2.5, 3.0) +
      c(1.0, 1.0, 1.0, 1.5, 1.5, 2.0, 2.0)
  )
  expect_equal(out[[1]]$id, rep(1, 7))
  #
  # two unconnected polygons don't get merged
  z <- matrix(c(1, 2, 1, 1, 2, 2), ncol = 3, nrow = 2, byrow = TRUE)
  out <- isobands(x = 1:3, y = 2:1, z, levels_low = 0.5, levels_high = 1.5)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(3.0, 2.5, 3.0, 1.0, 1.5, 1.5, 1.0) +
      c(1.5, 2.0, 2.0, 2.0, 2.0, 1.0, 1.0)
  )
  expect_setequal(out[[1]]$id, c(1:2))
  expect_equal(length(out[[1]]$id), 7)

  # two separate bands get merged in second row
  z <- matrix(c(1, 2, 1, 1, 2, 1, 0, 0, 0), ncol = 3, nrow = 3, byrow = TRUE)
  out <- isobands(x = 1:3, y = 3:1, z, levels_low = 0.5, levels_high = 1.5)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(3.0, 2.0, 1.0, 1.0, 1.0, 1.5, 1.5, 2.0, 2.5, 2.5, 3.0, 3.0) +
      c(1.50, 1.25, 1.50, 2.00, 3.00, 3.00, 2.00, 1.75, 2.00, 3.00, 3.00, 2.00)
  )
  expect_equal(out[[1]]$id, rep(1, 12))

  # circle gets closed
  z <- matrix(c(1, 1, 1, 1, 2, 1, 1, 1, 1), ncol = 3, nrow = 3, byrow = TRUE)
  out <- isobands(x = 1:3, y = 3:1, z, levels_low = 0.5, levels_high = 1.5)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(3.0, 2.0, 1.0, 1.0, 1.0, 2.0, 3.0, 3.0, 2.0, 2.5, 2.0, 1.5) +
      c(1.0, 1.0, 1.0, 2.0, 3.0, 3.0, 3.0, 2.0, 1.5, 2.0, 2.5, 2.0)
  )
  expect_setequal(out[[1]]$id, c(1:2))
  expect_equal(length(out[[1]]$id), 12)
})

test_that("NAs are handled correctly", {
  z <- matrix(c(NA, 1, 1, 1, 1, 1, 1, 1, 1), ncol = 3, nrow = 3, byrow = TRUE)
  out <- isobands(x = 1:3, y = 3:1, z, levels_low = 0.5, levels_high = 1.5)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 * c(3, 2, 1, 1, 2, 2, 3, 3) + c(1, 1, 1, 2, 2, 3, 3, 2)
  )
  expect_equal(out[[1]]$id, rep(1, 8))

  z <- matrix(c(NA, 1, 1, 1, 1, 1, 1, 1, NA), ncol = 3, nrow = 3, byrow = TRUE)
  out <- isobands(x = 1:3, y = 3:1, z, levels_low = 0.5, levels_high = 1.5)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 * c(1, 1, 2, 2, 2, 2, 3, 3) + c(1, 2, 2, 1, 2, 3, 3, 2)
  )
  expect_setequal(out[[1]]$id, c(1:2))
  expect_equal(length(out[[1]]$id), 8)
})


test_that("All elementary shapes are calculated correctly", {
  # a matrix that requires all elementary shapes for isobanding
  z <- matrix(
    c(
      0,
      0,
      0,
      1,
      0,
      2,
      1,
      0,
      1,
      1,
      1,
      2,
      2,
      0,
      2,
      1,
      2,
      2,
      0,
      0,
      0,
      1,
      0,
      2,
      1,
      0,
      1,
      1,
      1,
      2,
      2,
      0,
      2,
      1,
      2,
      2,
      0,
      1,
      0,
      2,
      1,
      0,
      1,
      1,
      1,
      2,
      2,
      0,
      2,
      1,
      2,
      2,
      0,
      0,
      1,
      0,
      1,
      1,
      1,
      2,
      2,
      0,
      2,
      1,
      2,
      2,
      0,
      0,
      0,
      1,
      0,
      2,
      2,
      0,
      2,
      1,
      2,
      2,
      0,
      0,
      0,
      1,
      0,
      2,
      1,
      0,
      1,
      1,
      1,
      2,
      0,
      1,
      0,
      2,
      1,
      0,
      1,
      1,
      1,
      2,
      2,
      0,
      2,
      1,
      2,
      2,
      0,
      0,
      2,
      0,
      2,
      1,
      2,
      2,
      0,
      0,
      0,
      1,
      0,
      2,
      1,
      0,
      1,
      1,
      1,
      2,
      1,
      0,
      1,
      1,
      1,
      2,
      2,
      0,
      2,
      1,
      2,
      2,
      0,
      0,
      0,
      1,
      0,
      2,
      0,
      1,
      0,
      2,
      1,
      0,
      1,
      1,
      1,
      2,
      2,
      0,
      2,
      1,
      2,
      2,
      0,
      0,
      0,
      0,
      0,
      1,
      0,
      2,
      1,
      0,
      1,
      1,
      1,
      2,
      2,
      0,
      2,
      1,
      2,
      2,
      0,
      0,
      0,
      1,
      0,
      2,
      1,
      0,
      1,
      1,
      1,
      2,
      2,
      0,
      2,
      1,
      2,
      2
    ),
    ncol = 18,
    nrow = 11,
    byrow = TRUE
  )
  out <- isobands(x = 1:18, y = 11:1, z, levels_low = 0.5, levels_high = 1.5)

  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(
        16.00,
        15.50,
        15.50,
        16.00,
        16.25,
        16.00,
        15.00,
        14.50,
        14.75,
        14.75,
        14.25,
        14.25,
        14.00,
        13.75,
        13.75,
        13.25,
        13.25,
        13.50,
        13.00,
        12.75,
        12.00,
        11.50,
        11.50,
        11.00,
        10.00,
        9.00,
        8.50,
        8.50,
        8.00,
        7.50,
        7.50,
        7.00,
        6.50,
        6.50,
        6.00,
        5.75,
        5.75,
        5.25,
        5.25,
        5.00,
        4.50,
        4.50,
        4.00,
        3.50,
        3.50,
        3.25,
        3.00,
        2.50,
        2.00,
        1.50,
        1.00,
        1.00,
        1.00,
        1.25,
        1.00,
        1.00,
        1.50,
        1.00,
        1.00,
        1.25,
        1.00,
        1.00,
        1.00,
        1.50,
        2.00,
        2.50,
        3.00,
        3.25,
        3.50,
        3.50,
        4.00,
        4.50,
        4.50,
        5.00,
        5.25,
        5.25,
        5.75,
        5.75,
        6.00,
        6.50,
        6.50,
        7.00,
        7.50,
        7.50,
        8.00,
        8.50,
        8.50,
        9.00,
        10.00,
        11.00,
        11.50,
        11.50,
        12.00,
        12.75,
        13.00,
        13.50,
        13.25,
        13.25,
        13.75,
        13.75,
        14.00,
        14.25,
        14.25,
        14.75,
        14.75,
        14.50,
        15.00,
        16.00,
        16.25,
        16.00,
        15.50,
        15.50,
        16.00,
        16.50,
        16.50,
        17.00,
        18.00,
        18.00,
        17.00,
        16.75,
        16.50,
        17.00,
        17.25,
        18.00,
        18.00,
        17.75,
        17.50,
        18.00,
        18.00,
        17.00,
        16.75,
        17.00,
        18.00,
        18.00,
        17.50,
        17.75,
        18.00,
        18.00,
        17.25,
        17.00,
        16.50,
        16.75,
        17.00,
        18.00,
        18.00,
        17.00,
        16.50,
        16.50,
        12.00,
        12.25,
        12.00,
        11.75,
        11.00,
        11.25,
        12.00,
        12.25,
        12.50,
        12.00,
        11.75,
        11.00,
        10.50,
        10.00,
        9.50,
        9.00,
        8.75,
        9.00,
        9.50,
        10.00,
        6.00,
        6.50,
        6.00,
        5.50,
        4.00,
        4.50,
        4.00,
        3.75,
        13.00,
        14.00,
        15.00,
        15.50,
        15.00,
        14.50,
        14.00,
        13.50,
        13.00,
        12.75,
        8.00,
        8.25,
        9.00,
        9.50,
        9.00,
        8.00,
        7.00,
        6.75,
        7.00,
        7.75,
        7.00,
        7.25,
        7.00,
        6.25,
        6.00,
        5.00,
        4.50,
        5.00,
        6.00,
        6.25,
        7.00,
        7.25,
        7.00,
        6.00,
        5.50,
        5.00,
        4.50,
        4.00,
        3.75,
        4.00,
        4.50,
        5.00,
        5.50,
        6.00,
        2.00,
        2.50,
        2.25,
        2.00,
        1.75,
        1.50,
        11.00,
        11.25,
        11.00,
        10.50,
        13.00,
        13.50,
        13.00,
        12.75,
        12.00,
        12.25,
        12.00,
        11.75,
        11.00,
        11.25,
        11.00,
        10.00,
        9.50,
        10.00,
        9.00,
        8.25,
        8.00,
        7.75,
        7.00,
        6.75,
        7.00,
        8.00,
        9.00,
        9.50,
        16.25,
        16.00,
        15.00,
        14.50,
        15.00,
        16.00,
        15.00,
        14.00,
        13.00,
        12.75,
        13.00,
        13.50,
        14.00,
        14.50,
        15.00,
        15.50,
        12.00,
        12.50,
        12.25,
        12.00,
        11.25,
        11.00,
        10.00,
        9.50,
        9.00,
        8.75,
        9.00,
        9.50,
        10.00,
        10.50,
        11.00,
        11.75,
        11.00,
        11.25,
        11.00,
        10.50,
        6.00,
        5.50,
        6.00,
        6.50,
        3.00,
        2.50,
        3.00,
        3.25,
        3.00,
        3.50,
        3.00,
        2.75,
        2.00,
        2.25,
        2.50,
        2.00,
        1.50,
        1.75,
        3.00,
        2.75,
        3.00,
        3.50,
        4.00,
        3.75,
        4.00,
        4.50,
        12.00,
        12.25,
        12.00,
        11.75,
        6.00,
        6.50,
        6.00,
        5.50
      ) +
      c(
        1.00,
        1.00,
        2.00,
        2.50,
        3.00,
        3.50,
        3.25,
        3.00,
        2.00,
        1.00,
        1.00,
        2.00,
        2.50,
        2.00,
        1.00,
        1.00,
        2.00,
        3.00,
        3.25,
        3.00,
        2.25,
        2.00,
        1.00,
        1.00,
        1.00,
        1.00,
        1.00,
        2.00,
        2.50,
        2.00,
        1.00,
        1.00,
        1.00,
        2.00,
        2.25,
        2.00,
        1.00,
        1.00,
        2.00,
        2.50,
        2.00,
        1.00,
        1.00,
        1.00,
        2.00,
        3.00,
        3.50,
        3.00,
        2.50,
        3.00,
        3.50,
        4.00,
        4.50,
        5.00,
        5.25,
        5.75,
        6.00,
        6.25,
        6.75,
        7.00,
        7.50,
        8.00,
        8.50,
        9.00,
        9.50,
        9.00,
        8.50,
        9.00,
        10.00,
        11.00,
        11.00,
        11.00,
        10.00,
        9.50,
        10.00,
        11.00,
        11.00,
        10.00,
        9.75,
        10.00,
        11.00,
        11.00,
        11.00,
        10.00,
        9.50,
        10.00,
        11.00,
        11.00,
        11.00,
        11.00,
        11.00,
        10.00,
        9.75,
        9.00,
        8.75,
        9.00,
        10.00,
        11.00,
        11.00,
        10.00,
        9.50,
        10.00,
        11.00,
        11.00,
        10.00,
        9.00,
        8.75,
        8.50,
        9.00,
        9.50,
        10.00,
        11.00,
        11.00,
        11.00,
        10.00,
        9.75,
        9.75,
        9.25,
        9.25,
        9.00,
        8.00,
        7.50,
        8.00,
        8.75,
        8.25,
        8.00,
        7.00,
        6.75,
        6.25,
        6.50,
        6.00,
        5.50,
        5.75,
        5.25,
        5.00,
        4.00,
        3.75,
        3.25,
        4.00,
        4.50,
        4.00,
        3.00,
        2.75,
        2.75,
        2.25,
        2.25,
        2.00,
        1.00,
        2.75,
        3.00,
        3.25,
        3.00,
        2.50,
        3.00,
        3.75,
        4.00,
        5.00,
        5.25,
        5.00,
        4.25,
        4.00,
        3.50,
        4.00,
        4.25,
        4.00,
        3.50,
        3.00,
        2.50,
        2.75,
        3.00,
        3.25,
        3.00,
        2.50,
        3.00,
        3.50,
        3.00,
        3.75,
        3.50,
        3.75,
        4.00,
        4.50,
        5.00,
        5.50,
        5.00,
        4.50,
        4.00,
        3.50,
        4.00,
        4.75,
        5.00,
        5.50,
        5.50,
        5.50,
        5.00,
        4.75,
        4.00,
        3.50,
        4.00,
        4.25,
        5.00,
        5.25,
        5.50,
        6.00,
        6.50,
        6.75,
        7.00,
        7.75,
        8.00,
        8.50,
        8.25,
        8.00,
        7.50,
        7.00,
        6.50,
        6.00,
        5.50,
        5.00,
        4.50,
        4.00,
        3.75,
        3.50,
        4.00,
        5.00,
        5.50,
        5.00,
        4.00,
        4.75,
        5.00,
        5.25,
        5.00,
        5.50,
        6.00,
        6.50,
        6.00,
        5.75,
        6.00,
        6.25,
        6.00,
        5.75,
        6.00,
        6.25,
        6.50,
        6.00,
        5.50,
        7.25,
        8.00,
        8.50,
        8.00,
        7.25,
        7.00,
        6.50,
        6.50,
        6.50,
        7.00,
        6.00,
        6.50,
        6.50,
        6.00,
        5.50,
        5.50,
        8.25,
        8.50,
        8.25,
        8.00,
        7.50,
        7.00,
        6.50,
        7.00,
        7.50,
        8.00,
        6.75,
        7.00,
        8.00,
        8.25,
        9.00,
        9.50,
        9.50,
        9.00,
        8.50,
        8.00,
        7.75,
        8.00,
        8.50,
        8.00,
        7.75,
        7.00,
        6.75,
        7.00,
        7.25,
        7.00,
        6.25,
        6.00,
        5.75,
        6.00,
        6.25,
        6.00,
        5.75,
        6.00,
        6.75,
        7.00,
        7.50,
        7.00,
        6.50,
        7.00,
        8.00,
        8.50,
        8.00,
        7.00,
        5.25,
        5.00,
        4.50,
        5.00,
        9.50,
        9.00,
        8.50,
        9.00,
        8.75,
        9.00,
        9.25,
        9.00,
        8.75,
        9.00,
        9.25,
        9.00
      )
  )
  expect_setequal(out[[1]]$id, c(1:26))
  expect_equal(length(out[[1]]$id), 324)
})


test_that("Six-sided saddles", {
  # a matrix that contains all six-sided saddles
  z <- matrix(
    c(0, 1, 1, 2, 1, 0, 2, 1, 0, 1, 1, 2),
    ncol = 4,
    nrow = 3,
    byrow = TRUE
  )
  # midpoint outside the band
  out <- isobands(x = 1:4, y = 3:1, z, levels_low = 0.6, levels_high = 1.4)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(
        3.0,
        2.0,
        1.6,
        2.0,
        2.3,
        2.0,
        1.6,
        2.0,
        3.0,
        3.4,
        3.0,
        2.7,
        3.0,
        3.4,
        1.0,
        1.0,
        1.0,
        1.4,
        4.0,
        4.0,
        4.0,
        3.6
      ) +
      c(
        1.0,
        1.0,
        1.0,
        1.4,
        2.0,
        2.6,
        3.0,
        3.0,
        3.0,
        3.0,
        2.6,
        2.0,
        1.4,
        1.0,
        1.6,
        2.0,
        2.4,
        2.0,
        2.4,
        2.0,
        1.6,
        2.0
      )
  )
  expect_setequal(out[[1]]$id, c(1:3))
  expect_equal(length(out[[1]]$id), 22)

  # midpoint inside the band
  out <- isobands(x = 1:4, y = 3:1, z, levels_low = 0.4, levels_high = 1.6)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(
        3.0,
        2.0,
        1.4,
        1.0,
        1.0,
        1.0,
        1.4,
        2.0,
        3.0,
        3.6,
        4.0,
        4.0,
        4.0,
        3.6,
        3.0,
        3.4,
        3.0,
        2.8,
        2.0,
        2.2,
        2.0,
        1.6
      ) +
      c(
        1.0,
        1.0,
        1.0,
        1.4,
        2.0,
        2.6,
        3.0,
        3.0,
        3.0,
        3.0,
        2.6,
        2.0,
        1.4,
        1.0,
        1.6,
        2.0,
        2.4,
        2.0,
        1.6,
        2.0,
        2.4,
        2.0
      )
  )
  expect_setequal(out[[1]]$id, c(1:3))
  expect_equal(length(out[[1]]$id), 22)
})


test_that("Seven-sided saddles", {
  # a matrix that contains all seven-sided saddles
  z <- matrix(
    c(0, 1, 0, 1, 2, 1, 2, 0, 2, 2, 0, 2, 0, 1, 0, 1, 2, 1),
    ncol = 6,
    nrow = 3,
    byrow = TRUE
  )
  # midpoint inside the band
  out <- isobands(x = 1:6, y = 3:1, z, levels_low = 0.5, levels_high = 1.5)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(
        6.00,
        6.00,
        5.50,
        5.00,
        4.50,
        4.00,
        3.50,
        3.00,
        2.50,
        2.00,
        1.50,
        1.00,
        1.00,
        1.25,
        1.00,
        1.00,
        1.50,
        2.00,
        2.50,
        3.00,
        3.50,
        4.00,
        4.50,
        5.00,
        5.50,
        6.00,
        6.00,
        5.75,
        4.00,
        4.25,
        4.00,
        3.00,
        2.75,
        3.00,
        2.00,
        2.25,
        2.00,
        1.75,
        5.00,
        5.25,
        5.00,
        4.75
      ) +
      c(
        1.50,
        1.00,
        1.00,
        1.25,
        1.00,
        1.00,
        1.00,
        1.25,
        1.00,
        1.00,
        1.00,
        1.25,
        1.75,
        2.00,
        2.25,
        2.75,
        3.00,
        3.00,
        3.00,
        2.75,
        3.00,
        3.00,
        3.00,
        2.75,
        3.00,
        3.00,
        2.50,
        2.00,
        1.50,
        2.00,
        2.50,
        2.25,
        2.00,
        1.75,
        1.50,
        2.00,
        2.50,
        2.00,
        1.75,
        2.00,
        2.25,
        2.00
      )
  )
  expect_setequal(out[[1]]$id, c(1:4))
  expect_equal(length(out[[1]]$id), 42)

  # midpoint outside the band
  out <- isobands(x = 1:6, y = 3:1, z, levels_low = 0.8, levels_high = 1.2)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(
        6.0,
        6.0,
        5.8,
        5.0,
        4.4,
        5.0,
        5.6,
        4.2,
        4.0,
        3.8,
        3.0,
        2.4,
        3.0,
        3.8,
        4.0,
        4.2,
        4.0,
        3.0,
        2.6,
        3.0,
        4.0,
        2.2,
        2.0,
        1.8,
        2.0,
        1.0,
        1.4,
        1.0,
        1.0,
        1.6,
        1.0,
        5.0,
        5.4,
        5.0,
        4.6,
        6.0,
        5.8,
        6.0,
        2.2,
        2.0,
        1.8,
        2.0
      ) +
      c(
        1.2,
        1.0,
        1.0,
        1.4,
        2.0,
        2.6,
        2.0,
        1.0,
        1.0,
        1.0,
        1.4,
        2.0,
        2.6,
        3.0,
        3.0,
        3.0,
        2.8,
        2.4,
        2.0,
        1.6,
        1.2,
        1.0,
        1.0,
        1.0,
        1.2,
        1.6,
        2.0,
        2.4,
        2.6,
        2.0,
        1.4,
        1.6,
        2.0,
        2.4,
        2.0,
        2.8,
        3.0,
        3.0,
        3.0,
        2.8,
        3.0,
        3.0
      )
  )
  expect_setequal(out[[1]]$id, c(1:8))
  expect_equal(length(out[[1]]$id), 42)
})

test_that("Eight-sided saddles", {
  # a matrix that contains all eight-sided saddles
  z <- matrix(c(0, 2, 0, 2, 0, 2), ncol = 3, nrow = 2, byrow = TRUE)
  # midpoint above the band
  out <- isobands(x = 1:3, y = 2:1, z, levels_low = 0.5, levels_high = 0.8)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(
        3.00,
        3.00,
        2.60,
        2.75,
        2.00,
        2.40,
        2.25,
        2.00,
        1.75,
        1.60,
        1.00,
        1.00,
        1.25,
        1.40
      ) +
      c(
        1.75,
        1.60,
        2.00,
        2.00,
        1.40,
        1.00,
        1.00,
        1.25,
        1.00,
        1.00,
        1.60,
        1.75,
        2.00,
        2.00
      )
  )
  expect_setequal(out[[1]]$id, c(1:3))
  expect_equal(length(out[[1]]$id), 14)

  # midpoint inside the band
  out <- isobands(x = 1:3, y = 2:1, z, levels_low = 0.5, levels_high = 1.5)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(
        2.75,
        2.25,
        2.00,
        1.75,
        1.25,
        1.00,
        1.00,
        1.25,
        1.75,
        2.00,
        2.25,
        2.75,
        3.00,
        3.00
      ) +
      c(
        1.00,
        1.00,
        1.25,
        1.00,
        1.00,
        1.25,
        1.75,
        2.00,
        2.00,
        1.75,
        2.00,
        2.00,
        1.75,
        1.25
      )
  )
  expect_equal(out[[1]]$id, rep(1, 14))

  # midpoint below the band
  out <- isobands(x = 1:3, y = 2:1, z, levels_low = 1.2, levels_high = 1.5)
  expect_setequal(
    10000 * out[[1]]$x + out[[1]]$y,
    10000 *
      c(
        3.00,
        3.00,
        2.75,
        2.60,
        2.40,
        2.00,
        1.60,
        1.75,
        2.00,
        2.25,
        1.40,
        1.25,
        1.00,
        1.00
      ) +
      c(
        1.40,
        1.25,
        1.00,
        1.00,
        2.00,
        1.60,
        2.00,
        2.00,
        1.75,
        2.00,
        1.00,
        1.00,
        1.25,
        1.40
      )
  )
  expect_setequal(out[[1]]$id, c(1:3))
  expect_equal(length(out[[1]]$id), 14)
})


test_that("Inconsistent numbers of isoband levels cause an error", {
  m <- matrix(
    c(0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0),
    4,
    4,
    byrow = TRUE
  )

  # single values are recycled
  expect_silent(
    isobands(1:4, 1:4, m, 0.5, c(0.5, 1.5))
  )

  expect_silent(
    isobands(1:4, 1:4, m, c(0.5, 1.5), 0.5)
  )

  # error, multiple values are not recycled
  expect_snapshot(
    isobands(1:4, 1:4, m, c(0.5, 1.5, 2.5), c(0.5, 1.5)),
    error = TRUE
  )

  expect_snapshot(
    isobands(1:4, 1:4, m, c(0.5, 1.5), c(0.5, 1.5, 2.5)),
    error = TRUE
  )
})


test_that("Swap isoband levels if given in the wrong order", {
  m <- matrix(
    c(0, 0, 1, 1, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0),
    4,
    4,
    byrow = TRUE
  )

  out1 <- isobands(1:4, 1:4, m, c(-.5, 0.5), c(0.5, 1.5))
  out2 <- isobands(1:4, 1:4, m, c(0.5, 1.5), c(-.5, 0.5))

  expect_equal(out1, out2)
})