bpo-33855: More edits and new minimal tests for IDLE (GH-7761)

Part 2 of 3.  Continues PR #7689, changeset ee5ef30.
Edit and add tests for 18 modules, help_about to replace and run.

Lib/idlelib/idle_test/test_pyshell.py

@@ -0,0 +1,42 @@
+"Test pyshell, coverage 12%."
+# Plus coverage of test_warning.  Was 20% with test_openshell.
+
+from idlelib import pyshell
+import unittest
+from test.support import requires
+from tkinter import Tk
+
+
+class PyShellFileListTest(unittest.TestCase):
+
+    @classmethod
+    def setUpClass(cls):
+        requires('gui')
+        cls.root = Tk()
+        cls.root.withdraw()
+
+    @classmethod
+    def tearDownClass(cls):
+        #cls.root.update_idletasks()
+##        for id in cls.root.tk.call('after', 'info'):
+##            cls.root.after_cancel(id)  # Need for EditorWindow.
+        cls.root.destroy()
+        del cls.root
+
+    def test_init(self):
+        psfl = pyshell.PyShellFileList(self.root)
+        self.assertEqual(psfl.EditorWindow, pyshell.PyShellEditorWindow)
+        self.assertIsNone(psfl.pyshell)
+
+# The following sometimes causes 'invalid command name "109734456recolorize"'.
+# Uncommenting after_cancel above prevents this, but results in
+# TclError: bad window path name ".!listedtoplevel.!frame.text"
+# which is normally prevented by after_cancel.
+##    def test_openshell(self):
+##        pyshell.use_subprocess = False
+##        ps = pyshell.PyShellFileList(self.root).open_shell()
+##        self.assertIsInstance(ps, pyshell.PyShell)
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2)