test_that("'EI' works for a matrix", {
  curves <- array(c(1, 0, 1, 0, 0, 1, 0, 1), dim = c(2, 4))
  expect_equal(EI(curves), 1 - c(0.5, 0.5))
})

test_that("'EI' works for a 3-dimensional array", {
  curves <- array(c(1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1), dim = c(2, 4, 2))
  expect_equal(EI(curves), 1 - c(0.5, 0.5))
})

test_that("'EI' does not work for a 4-dimensional array and (for example) for the print function", {
  curves <- array(c(1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1), dim = c(2, 2, 2, 2))
  expect_error(EI(curves))
  expect_error(EI(print))
})

test_that("'HI' works for a matrix", {
  curves <- array(c(1, 0, 1, 0, 0, 1, 0, 1), dim = c(2, 4))
  expect_equal(HI(curves), c(0.5, 0.5))
})

test_that("'HI' works for a 3-dimensional array", {
  curves <- array(c(1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1), dim = c(2, 4, 2))
  expect_equal(HI(curves), c(0.5, 0.5))
})

test_that("'HI' does not work for a string", {
  expect_error(HI("I will throw an error"))
})

test_that("'MEI' works for a matrix", {
  curves <- array(c(1, 0, 1, 0, 0, 1, 0, 1), dim = c(2, 4))
  expect_equal(MEI(curves), 1 - c(0.75, 0.75))
})

test_that("'MEI' works for a 3-dimensional array", {
  curves <- array(c(1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1), dim = c(2, 4, 2))
  expect_equal(MEI(curves), 1 - c(0.75, 0.75))
})

test_that("'MEI' does not work for a complex number", {
  expect_error(MEI(1 + 2i))
})

test_that("'MHI' works for a matrix", {
  curves <- array(c(1, 0, 1, 0, 0, 1, 0, 1), dim = c(2, 4))
  expect_equal(MHI(curves), c(0.75, 0.75))
})

test_that("'MHI' works for a 3-dimensional array", {
  curves <- array(c(1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1), dim = c(2, 4, 2))
  expect_equal(MHI(curves), c(0.75, 0.75))
})

test_that("'MEI' does not work for a boolean", {
  expect_error(MEI(FALSE))
})

test_that("'generate_indices' works for a matrix", {
  curves <- array(c(1, 0, 1, 0, 0, 1, 0, 1), dim = c(2, 4))

  res <- generate_indices(curves, indices = c("EI", "MHI"))

  expect_equal(dim(res), c(2, 6))
  expect_equal(res[2, 1], 0.5)
})

test_that("'generate_indices' works for a 3-dimnensional array", {
  curves <- array(c(1, 2, 3, 3, 2, 1, 5, 2, 3, 9, 8, 7, -1, -5, -6, 2, 3, 0, -1, 0, 2, -1, -2, 0),
    dim = c(3, 4, 2)
  )

  res <- suppressWarnings(generate_indices(curves, indices = c("EI", "MHI")))

  expect_equal(dim(res), c(3, 6))
  expect_equal(res[2, 1], 0.666666666666666740681)
})