test_that("isSheetVeryHidden identifies very hidden sheets correctly in XLS", {
  wb.xls <- loadWorkbook("resources/testWorkbookHiddenSheets.xls", create = FALSE)
  expect_true(isSheetVeryHidden(wb.xls, 4))
  expect_true(isSheetVeryHidden(wb.xls, "DDD"))
})

test_that("isSheetVeryHidden identifies non-very hidden sheets correctly in XLS", {
  wb.xls <- loadWorkbook("resources/testWorkbookHiddenSheets.xls", create = FALSE)
  expect_false(isSheetVeryHidden(wb.xls, 1))
  expect_false(isSheetVeryHidden(wb.xls, "AAA"))
  expect_false(isSheetVeryHidden(wb.xls, 2)) # Sheet is actually hidden only!
  expect_false(isSheetVeryHidden(wb.xls, "BBB")) # Sheet is actually hidden only!
  expect_false(isSheetVeryHidden(wb.xls, 3))
  expect_false(isSheetVeryHidden(wb.xls, "CCC"))
})

test_that("isSheetVeryHidden throws errors for invalid/non-existing sheets in XLS", {
  wb.xls <- loadWorkbook("resources/testWorkbookHiddenSheets.xls", create = FALSE)
  expect_error(isSheetVeryHidden(wb.xls, 200))
  expect_error(isSheetVeryHidden(wb.xls, "Sheet does not exist"))
  expect_error(isSheetVeryHidden(wb.xls, "'Illegal sheet name"))
})

test_that("isSheetVeryHidden identifies very hidden sheets correctly in XLSX", {
  wb.xlsx <- loadWorkbook("resources/testWorkbookHiddenSheets.xlsx", create = FALSE)
  expect_true(isSheetVeryHidden(wb.xlsx, 4))
  expect_true(isSheetVeryHidden(wb.xlsx, "DDD"))
})

test_that("isSheetVeryHidden identifies non-very hidden sheets correctly in XLSX", {
  wb.xlsx <- loadWorkbook("resources/testWorkbookHiddenSheets.xlsx", create = FALSE)
  expect_false(isSheetVeryHidden(wb.xlsx, 1))
  expect_false(isSheetVeryHidden(wb.xlsx, "AAA"))
  expect_false(isSheetVeryHidden(wb.xlsx, 2)) # Sheet is actually hidden only!
  expect_false(isSheetVeryHidden(wb.xlsx, "BBB")) # Sheet is actually hidden only!
  expect_false(isSheetVeryHidden(wb.xlsx, 3))
  expect_false(isSheetVeryHidden(wb.xlsx, "CCC"))
})

test_that("isSheetVeryHidden throws errors for invalid/non-existing sheets in XLSX", {
  wb.xlsx <- loadWorkbook("resources/testWorkbookHiddenSheets.xlsx", create = FALSE)
  expect_error(isSheetVeryHidden(wb.xlsx, 200))
  expect_error(isSheetVeryHidden(wb.xlsx, "Sheet does not exist"))
  expect_error(isSheetVeryHidden(wb.xlsx, "'Illegal sheet name"))
})