gh-155648: Fix IDLE tests that cannot fail (#156257)

test_autocomplete.py:241 passes when proper because any([]) is True is true. It would also pass if small only had underscored words because the filter got reversed. Change logic and replace filter with generator expression
using slice instead of startswith. Change line 242 to match.

test_editor.py:236 and test_configdialog.py:55 have empty tests ('pass'); skip them for now.
PR-#156260 add real tests.

template.py:25 tests True == True; skip it. With this, the bug scanner should be satisfied while allowing
setUpClass and tearDownClass to run and be verified.

Remove duplicate and confusing fetch_completions call.

Author: terryjreedy

Lib/idlelib/idle_test/template.py

@@ -21,6 +21,7 @@ def tearDownClass(cls):
         cls.root.destroy()
         del cls.root
 
+    @unittest.skip('Dummy test')
     def test_init(self):
         self.assertTrue(True)
 

Lib/idlelib/idle_test/test_autocomplete.py

@@ -230,16 +230,14 @@ def test_fetch_completions(self):
         # For file completion, a large list containing all files in the path,
         # and a small list containing files that do not start with '.'.
         acp = self.autocomplete
-        small, large = acp.fetch_completions(
-                '', ac.ATTRS)
-        if hasattr(__main__, '__file__') and __main__.__file__ != ac.__file__:
-            self.assertNotIn('AutoComplete', small)  # See issue 36405.
 
-        # Test attributes
-        s, b = acp.fetch_completions('', ac.ATTRS)
-        self.assertLess(len(small), len(large))
-        self.assertTrue(all(filter(lambda x: x.startswith('_'), s)))
-        self.assertTrue(any(filter(lambda x: x.startswith('_'), b)))
+        # Test current module (what='') attributes.
+        small, large = acp.fetch_completions('', ac.ATTRS)
+        if hasattr(__main__, '__file__') and __main__.__file__ != ac.__file__:
+            self.assertNotIn('AutoComplete', small)  # See gh-80586.
+        self.assertLess(len(small), len(large))  # Not equal
+        self.assertFalse(any(a[:1] == '_' for a in small))
+        self.assertTrue(any(a[:1] == '_' for a in large))
 
         # Test smalll should respect to __all__.
         with patch.dict('__main__.__dict__', {'__all__': ['a', 'b']}):

Lib/idlelib/idle_test/test_configdialog.py

@@ -50,6 +50,7 @@ def tearDownModule():
     root = dialog = None
 
 
+@unittest.skip('Empty tests')
 class ConfigDialogTest(unittest.TestCase):
 
     def test_deactivate_current_config(self):

Lib/idlelib/idle_test/test_editor.py

@@ -211,6 +211,7 @@ def test_searcher(self):
                 self.assertEqual(actual_pair, expected_pair)
 
 
+@unittest.skip('Empty test')
 class RMenuTest(unittest.TestCase):
 
     @classmethod