The saveWorkbook() routine always returns TRUE. Its return status is not documented, and rightfully so since it is constant!

However, on Windows platforms (precisely where openxlsx is likely to be used....), if you happen to have the targeted file opened in Excel, the write operation will fail!!

It would be useful for saveWorkbook() to at least return a boolean "success status" and yield FALSE when saving fails. Another option would be to add an argument (FALSE by default, to not overcomplicate the logic for those who do not care much) to trigger an exception when writing fails.