test_that("isSheetHidden identifies hidden sheets correctly in XLS", {
  # Check if sheets are hidden (*.xls)
  wb.xls <- loadWorkbook("resources/testWorkbookHiddenSheets.xls", create = FALSE)
  expect_true(isSheetHidden(wb.xls, 2))
  expect_true(isSheetHidden(wb.xls, "BBB"))
})

test_that("isSheetHidden identifies non-hidden sheets correctly in XLS", {
  wb.xls <- loadWorkbook("resources/testWorkbookHiddenSheets.xls", create = FALSE)
  expect_false(isSheetHidden(wb.xls, 1))
  expect_false(isSheetHidden(wb.xls, "AAA"))
  expect_false(isSheetHidden(wb.xls, 3))
  expect_false(isSheetHidden(wb.xls, "CCC"))
  expect_false(isSheetHidden(wb.xls, 4)) # Sheet is actually very hidden!
  expect_false(isSheetHidden(wb.xls, "DDD")) # Sheet is actually very hidden!
})

test_that("isSheetHidden throws errors for invalid/non-existing sheets in XLS", {
  # Check if quering invalid/non-existing sheets
  # causes an exception (*.xls)
  wb.xls <- loadWorkbook("resources/testWorkbookHiddenSheets.xls", create = FALSE)
  expect_error(isSheetHidden(wb.xls, 200))
  expect_error(isSheetHidden(wb.xls, "Sheet does not exist"))
  expect_error(isSheetHidden(wb.xls, "'Illegal sheet name"))
})

test_that("isSheetHidden identifies hidden sheets correctly in XLSX", {
  # Check if sheets are hidden (*.xlsx)
  wb.xlsx <- loadWorkbook("resources/testWorkbookHiddenSheets.xlsx", create = FALSE)
  expect_true(isSheetHidden(wb.xlsx, 2))
  expect_true(isSheetHidden(wb.xlsx, "BBB"))
})

test_that("isSheetHidden identifies non-hidden sheets correctly in XLSX", {
  wb.xlsx <- loadWorkbook("resources/testWorkbookHiddenSheets.xlsx", create = FALSE)
  expect_false(isSheetHidden(wb.xlsx, 1))
  expect_false(isSheetHidden(wb.xlsx, "AAA"))
  expect_false(isSheetHidden(wb.xlsx, 3))
  expect_false(isSheetHidden(wb.xlsx, "CCC"))
  expect_false(isSheetHidden(wb.xlsx, 4)) # Sheet is actually very hidden!
  expect_false(isSheetHidden(wb.xlsx, "DDD")) # Sheet is actually very hidden!
})

test_that("isSheetHidden throws errors for invalid/non-existing sheets in XLSX", {
  # Check if quering invalid/non-existing sheets
  # causes an exception (*.xlsx)
  wb.xlsx <- loadWorkbook("resources/testWorkbookHiddenSheets.xlsx", create = FALSE)
  expect_error(isSheetHidden(wb.xlsx, 200))
  expect_error(isSheetHidden(wb.xlsx, "Sheet does not exist"))
  expect_error(isSheetHidden(wb.xlsx, "'Illegal sheet name"))
})