pythongh-71339: Use new assertion methods in test_idle (pythonGH-129213)

Revise 10 tests in 7 files, with 1 test split into 2.
(cherry picked from commit dbb25ce)

Co-authored-by: Terry Jan Reedy <tjreedy@udel.edu>

Lib/idlelib/idle_test/test_configdialog.py

@@ -98,8 +98,8 @@ def test_click_help(self):
             dialog.buttons['Help'].invoke()
             title, contents = view.kwds['title'], view.kwds['contents']
         self.assertEqual(title, 'Help for IDLE preferences')
-        self.assertTrue(contents.startswith('When you click') and
-                        contents.endswith('a different name.\n'))
+        self.assertStartsWith(contents, 'When you click')
+        self.assertEndsWith(contents,'a different name.\n')
 
 
 class FontPageTest(unittest.TestCase):

Lib/idlelib/idle_test/test_debugger.py

@@ -256,7 +256,7 @@ def test_init(self):
         flist = None
         master_window = self.root
         sv = debugger.StackViewer(master_window, flist, gui)
-        self.assertTrue(hasattr(sv, 'stack'))
+        self.assertHasAttr(sv, 'stack')
 
     def test_load_stack(self):
         # Test the .load_stack() method against a fixed test stack.

Lib/idlelib/idle_test/test_grep.py

@@ -143,7 +143,7 @@ def test_found(self):
         self.assertIn(pat, lines[0])
         self.assertIn('py: 1:', lines[1])  # line number 1
         self.assertIn('2', lines[3])  # hits found 2
-        self.assertTrue(lines[4].startswith('(Hint:'))
+        self.assertStartsWith(lines[4], '(Hint:')
 
 
 class Default_commandTest(unittest.TestCase):

Lib/idlelib/idle_test/test_multicall.py

@@ -27,7 +27,7 @@ def tearDownClass(cls):
     def test_creator(self):
         mc = self.mc
         self.assertIs(multicall._multicall_dict[Text], mc)
-        self.assertTrue(issubclass(mc, Text))
+        self.assertIsSubclass(mc, Text)
         mc2 = multicall.MultiCallCreator(Text)
         self.assertIs(mc, mc2)
 

Lib/idlelib/idle_test/test_query.py

@@ -134,10 +134,10 @@ def test_c_source_name(self):
 
     def test_good_module_name(self):
         dialog = self.Dummy_ModuleName('idlelib')
-        self.assertTrue(dialog.entry_ok().endswith('__init__.py'))
+        self.assertEndsWith(dialog.entry_ok(), '__init__.py')
         self.assertEqual(dialog.entry_error['text'], '')
         dialog = self.Dummy_ModuleName('idlelib.idle')
-        self.assertTrue(dialog.entry_ok().endswith('idle.py'))
+        self.assertEndsWith(dialog.entry_ok(), 'idle.py')
         self.assertEqual(dialog.entry_error['text'], '')
 
 
@@ -389,7 +389,7 @@ def test_click_module_name(self):
         self.assertEqual(dialog.text0, 'idlelib')
         self.assertEqual(dialog.entry.get(), 'idlelib')
         dialog.button_ok.invoke()
-        self.assertTrue(dialog.result.endswith('__init__.py'))
+        self.assertEndsWith(dialog.result, '__init__.py')
         root.destroy()
 
 

Lib/idlelib/idle_test/test_redirector.py

@@ -34,7 +34,7 @@ def test_close(self):
         redir.register('insert', Func)
         redir.close()
         self.assertEqual(redir._operations, {})
-        self.assertFalse(hasattr(self.text, 'widget'))
+        self.assertNotHasAttr(self.text, 'widget')
 
 
 class WidgetRedirectorTest(unittest.TestCase):

Lib/idlelib/idle_test/test_sidebar.py

@@ -725,7 +725,7 @@ def test_copy(self):
 
         text.tag_add('sel', f'{first_line}.0', 'end-1c')
         selected_text = text.get('sel.first', 'sel.last')
-        self.assertTrue(selected_text.startswith('if True:\n'))
+        self.assertStartsWith(selected_text, 'if True:\n')
         self.assertIn('\n1\n', selected_text)
 
         text.event_generate('<<copy>>')
@@ -749,7 +749,7 @@ def test_copy_with_prompts(self):
 
         text.tag_add('sel', f'{first_line}.3', 'end-1c')
         selected_text = text.get('sel.first', 'sel.last')
-        self.assertTrue(selected_text.startswith('True:\n'))
+        self.assertStartsWith(selected_text, 'True:\n')
 
         selected_lines_text = text.get('sel.first linestart', 'sel.last')
         selected_lines = selected_lines_text.split('\n')