Issue18130: Test class idlelib.configSectionNameDialog.GetCfgSectionNameDialog.

Fix bug in existing human test and add instructions; fix two bugs in tested
code; remove redundancies, add spaces, and change two internal method names.
Add mock_tk with mocks for tkinter.Variable subclasses and tkinter.messagebox.
Use mocks in test_config_name to unittest methods that are otherwise gui-free.

Lib/idlelib/idle_test/test_config_name.py

@@ -0,0 +1,75 @@
+"""Unit tests for idlelib.configSectionNameDialog"""
+import unittest
+from idlelib.idle_test.mock_tk import Var, Mbox
+from idlelib import configSectionNameDialog as name_dialog_module
+
+name_dialog = name_dialog_module.GetCfgSectionNameDialog
+
+class Dummy_name_dialog:
+    # Mock for testing the following methods of name_dialog
+    name_ok = name_dialog.name_ok
+    Ok = name_dialog.Ok
+    Cancel = name_dialog.Cancel
+    # Attributes, constant or variable, needed for tests
+    used_names = ['used']
+    name = Var()
+    result = None
+    destroyed = False
+    def destroy(self):
+        self.destroyed = True
+
+# name_ok calls Mbox.showerror if name is not ok
+orig_mbox = name_dialog_module.tkMessageBox
+showerror = Mbox.showerror
+
+class TestConfigName(unittest.TestCase):
+    dialog = Dummy_name_dialog()
+   
+    @classmethod
+    def setUpClass(cls):
+        name_dialog_module.tkMessageBox = Mbox
+
+    @classmethod
+    def tearDownClass(cls):
+        name_dialog_module.tkMessageBox = orig_mbox
+
+    def test_blank_name(self):
+        self.dialog.name.set(' ')
+        self.assertEqual(self.dialog.name_ok(), '')
+        self.assertEqual(showerror.title, 'Name Error')
+        self.assertIn('No', showerror.message)
+        
+    def test_used_name(self):
+        self.dialog.name.set('used')
+        self.assertEqual(self.dialog.name_ok(), '')
+        self.assertEqual(showerror.title, 'Name Error')
+        self.assertIn('use', showerror.message)
+        
+    def test_long_name(self):
+        self.dialog.name.set('good'*8)
+        self.assertEqual(self.dialog.name_ok(), '')
+        self.assertEqual(showerror.title, 'Name Error')
+        self.assertIn('too long', showerror.message)
+
+    def test_good_name(self):
+        self.dialog.name.set('  good ')
+        showerror.title = 'No Error'  # should not be called
+        self.assertEqual(self.dialog.name_ok(), 'good')
+        self.assertEqual(showerror.title, 'No Error')
+        
+    def test_ok(self):
+        self.dialog.destroyed = False
+        self.dialog.name.set('good')
+        self.dialog.Ok()
+        self.assertEqual(self.dialog.result, 'good')
+        self.assertTrue(self.dialog.destroyed)
+
+    def test_cancel(self):
+        self.dialog.destroyed = False
+        self.dialog.Cancel()
+        self.assertEqual(self.dialog.result, '')
+        self.assertTrue(self.dialog.destroyed)
+        
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2, exit=False)