Improve type checking in common module, and delete unused function

tests/test_base/test_base_common.py

@@ -33,9 +33,9 @@ from PyQt5.QtGui import QDesktopServices
 from PyQt5.QtCore import QUrl
 
 from novelwriter.common import (
-    checkBool, checkFloat, checkHandle, checkInt, checkIntTuple, checkPath,
-    checkString, checkStringNone, checkUuid, formatInt, formatTime,
-    formatTimeStamp, formatVersion, fuzzyTime, getFileSize, hexToInt, isHandle, isItemClass,
+    checkBool, checkFloat, checkInt, checkIntTuple, checkPath, checkString,
+    checkStringNone, checkUuid, formatInt, formatTime, formatTimeStamp,
+    formatVersion, fuzzyTime, getFileSize, hexToInt, isHandle, isItemClass,
     isItemLayout, isItemType, isTitleTag, jsonEncode, makeFileNameSafe, minmax,
     numberToRoman, NWConfigParser, openExternalPath, readTextFile, simplified,
     transferCase, xmlIndent, yesNo
@@ -151,19 +151,6 @@ def testBaseCommon_checkBool():
 # END Test testBaseCommon_checkBool
 
 
-@pytest.mark.base
-def testBaseCommon_checkHandle():
-    """Test the checkHandle function."""
-    assert checkHandle("None", 1, True) is None
-    assert checkHandle("None", 1, False) == 1
-    assert checkHandle(None, 1, True) is None
-    assert checkHandle(None, 1, False) == 1
-    assert checkHandle("47666c91c7ccf", None, False) == "47666c91c7ccf"
-    assert checkHandle("h7666c91c7ccf", None, False) is None
-
-# END Test testBaseCommon_checkHandle
-
-
 @pytest.mark.base
 def testBaseCommon_checkUuid():
     """Test the checkUuid function."""
@@ -236,7 +223,7 @@ def testBaseCommon_isItemClass():
 
     # Invalid
     assert isItemClass("None") is False
-    assert isItemClass(None) is False  # type: ignore
+    assert isItemClass(None) is False
     assert isItemClass("STUFF") is False
 
 # END Test testBaseCommon_isItemClass