Issue #23964: Update idlelib/idle_test/README.txt. first patch by Al Sweigart.

Lib/idlelib/idle_test/README.txt

 README FOR IDLE TESTS IN IDLELIB.IDLE_TEST
 
+0. Quick Start
+
+Automated unit tests were added in 2.7 for Python 2.x and 3.3 for Python 3.x.
+To run the tests from a command line:
+
+python -m test.test_idle
+
+Human-mediated tests were added later in 2.7 and in 3.4.
+
+python -m idlelib.idle_test.htest
+
 
 1. Test Files
 
 The idle directory, idlelib, has over 60 xyz.py files. The idle_test
-subdirectory should contain a test_xyy.py for each. (For test modules, make
-'xyz' lower case, and possibly shorten it.) Each file should start with the
-something like the following template, with the blanks after after '.' and 'as',
-and before and after '_' filled in.
----
+subdirectory should contain a test_xyz.py for each, where 'xyz' is lowercased
+even if xyz.py is not. Here is a possible template, with the blanks after after
+'.' and 'as', and before and after '_' to be filled in.
+
 import unittest
 from test.support import requires
 import idlelib. as
@@ -18,33 +28,33 @@ class _Test(unittest.TestCase):
     def test_(self):
 
 if __name__ == '__main__':
-    unittest.main(verbosity=2, exit=2)
----
-Idle tests are run with unittest; do not use regrtest's test_main.
+    unittest.main(verbosity=2)
+
+Add the following at the end of xyy.py, with the appropriate name added after
+'test_'. Some files already have something like this for htest.  If so, insert
+the import and unittest.main lines before the htest lines.
 
-Once test_xyy is written, the following should go at the end of xyy.py,
-with xyz (lowercased) added after 'test_'.
----
 if __name__ == "__main__":
     import unittest
     unittest.main('idlelib.idle_test.test_', verbosity=2, exit=False)
----
 
 
-2. Gui Tests
 
-Gui tests need 'requires' from test.support (test.test_support in 2.7). A
-test is a gui test if it creates a Tk root or master object either directly
-or indirectly by instantiating a tkinter or idle class. For the benefit of
-test processes that either have no graphical environment available or are not
-allowed to use it, gui tests must be 'guarded' by "requires('gui')" in a
-setUp function or method. This will typically be setUpClass.
+2. GUI Tests
+
+When run as part of the Python test suite, Idle gui tests need to run
+test.support.requires('gui') (test.test_support in 2.7).  A test is a gui test
+if it creates a Tk root or master object either directly or indirectly by
+instantiating a tkinter or idle class.  For the benefit of test processes that
+either have no graphical environment available or are not allowed to use it, gui
+tests must be 'guarded' by "requires('gui')" in a setUp function or method.
+This will typically be setUpClass.
+
+To avoid interfering with other gui tests, all gui objects must be destroyed and
+deleted by the end of the test.  Widgets, such as a Tk root, created in a setUpX
+function, should be destroyed in the corresponding tearDownX.  Module and class
+widget attributes should also be deleted..
 
-To avoid interfering with other gui tests, all gui objects must be destroyed
-and deleted by the end of the test.  If a widget, such as a Tk root, is created
-in a setUpX function, destroy it in the corresponding tearDownX.  For module
-and class attributes, also delete the widget.
----
     @classmethod
     def setUpClass(cls):
         requires('gui')
@@ -54,49 +64,55 @@ and class attributes, also delete the widget.
     def tearDownClass(cls):
         cls.root.destroy()
         del cls.root
----
 
-Support.requires('gui') causes the test(s) it guards to be skipped if any of
+
+Requires('gui') causes the test(s) it guards to be skipped if any of
 a few conditions are met:
- - The tests are being run by regrtest.py, and it was started without
-   enabling the "gui" resource with the "-u" command line option.
+    
+ - The tests are being run by regrtest.py, and it was started without enabling
+   the "gui" resource with the "-u" command line option.
+   
  - The tests are being run on Windows by a service that is not allowed to
    interact with the graphical environment.
+   
  - The tests are being run on Mac OSX in a process that cannot make a window
    manager connection.
+   
  - tkinter.Tk cannot be successfully instantiated for some reason.
+ 
  - test.support.use_resources has been set by something other than
    regrtest.py and does not contain "gui".
+   
+Tests of non-gui operations should avoid creating tk widgets. Incidental uses of
+tk variables and messageboxes can be replaced by the mock classes in
+idle_test/mock_tk.py. The mock text handles some uses of the tk Text widget.
 
-Since non-gui tests always run, but gui tests only sometimes, tests of non-gui
-operations should best avoid needing a gui. Methods that make incidental use of
-tkinter (tk) variables and messageboxes can do this by using the mock classes in
-idle_test/mock_tk.py. There is also a mock text that will handle some uses of the
-tk Text widget.
 
+3. Running Unit Tests
 
-3. Running Tests
+Assume that xyz.py and test_xyz.py both end with a unittest.main() call.
+Running either from an Idle editor runs all tests in the test_xyz file with the
+version of Python running Idle.  Test output appears in the Shell window.  The
+'verbosity=2' option lists all test methods in the file, which is appropriate
+when developing tests. The 'exit=False' option is needed in xyx.py files when an
+htest follows.
 
-Assume that xyz.py and test_xyz.py end with the "if __name__" statements given
-above. In Idle, pressing F5 in an editor window with either loaded will run all
-tests in the test_xyz file with the version of Python running Idle.  The test
-report and any tracebacks will appear in the Shell window. The options in these
-"if __name__" statements are appropriate for developers running (as opposed to
-importing) either of the files during development: verbosity=2 lists all test
-methods in the file; exit=False avoids a spurious sys.exit traceback that would
-otherwise occur when running in Idle. The following command lines also run
-all test methods, including gui tests, in test_xyz.py. (The exceptions are that
-idlelib and idlelib.idle start Idle and idlelib.PyShell should (issue 18330).)
+The following command lines also run all test methods, including
+gui tests, in test_xyz.py. (Both '-m idlelib' and '-m idlelib.idle' start
+Idle and so cannot run tests.)
 
-python -m idlelib.xyz  # With the capitalization of the xyz module
+python -m idlelib.xyz
 python -m idlelib.idle_test.test_xyz
 
-To run all idle_test/test_*.py tests, either interactively
-('>>>', with unittest imported) or from a command line, use one of the
-following. (Notes: in 2.7, 'test ' (with the space) is 'test.regrtest ';
-where present, -v and -ugui can be omitted.)
+The following runs all idle_test/test_*.py tests interactively.
+
+>>> import unittest
+>>> unittest.main('idlelib.idle_test', verbosity=2)
+
+The following run all Idle tests at a command line.  Option '-v' is the same as
+'verbosity=2'.  (For 2.7, replace 'test' in the second line with
+'test.regrtest'.)
 
->>> unittest.main('idlelib.idle_test', verbosity=2, exit=False)
 python -m unittest -v idlelib.idle_test
 python -m test -v -ugui test_idle
 python -m test.test_idle
@@ -113,3 +129,15 @@ To run an individual Testcase or test method, extend the dotted name given to
 unittest on the command line.
 
 python -m unittest -v idlelib.idle_test.test_xyz.Test_case.test_meth
+
+
+4. Human-mediated Tests
+
+Human-mediated tests are widget tests that cannot be automated but need human
+verification. They are contained in idlelib/idle_test/htest.py, which has
+instructions.  (Some modules need an auxiliary function, identified with # htest
+# on the header line.)  The set is about complete, though some tests need
+improvement. To run all htests, run the htest file from an editor or from the
+command line with:
+
+python -m idlelib.idle_test.htest