Issue 18910: Edit idle_test/README.txt to add 'requires' usage at module scope.

Uppercase 'GUI', remove 2.7 references and reflow text.

Lib/idlelib/idle_test/README.txt

@@ -2,12 +2,12 @@ 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.
+Automated unit tests were added in 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.
+Human-mediated tests were added later in 3.4.
 
 python -m idlelib.idle_test.htest
 
@@ -15,9 +15,10 @@ 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_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.
+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
@@ -30,9 +31,9 @@ class _Test(unittest.TestCase):
 if __name__ == '__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.
+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.
 
 if __name__ == "__main__":
     import unittest
@@ -42,18 +43,25 @@ if __name__ == "__main__":
 
 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.
+When run as part of the Python test suite, Idle GUI tests need to run
+test.support.requires('gui').  A test is a GUI test if it creates a
+tkinter.Tk root or master object either directly or indirectly by
+instantiating a tkinter or idle class.  GUI tests cannot run in test
+processes that either have no graphical environment available or are not
+allowed to use it.
 
-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 guard a module consisting entirely of GUI tests, start with
+
+from test.support import requires
+requires('gui')
+
+To guard a test class, put "requires('gui')" in its setUpClass function.
+
+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.
 
     @classmethod
     def setUpClass(cls):
@@ -69,37 +77,38 @@ widget attributes should also be deleted..
 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 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.
+ - 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.
+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.
 
 
 3. Running Unit 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.
+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.
 
 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.)
+gui tests, in test_xyz.py. (Both '-m idlelib' and '-m idlelib.idle'
+start Idle and so cannot run tests.)
 
 python -m idlelib.xyz
 python -m idlelib.idle_test.test_xyz
@@ -109,35 +118,35 @@ 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'.)
+The following run all Idle tests at a command line.  Option '-v' is the
+same as 'verbosity=2'.
 
 python -m unittest -v idlelib.idle_test
 python -m test -v -ugui test_idle
 python -m test.test_idle
 
-The idle tests are 'discovered' by idlelib.idle_test.__init__.load_tests,
-which is also imported into test.test_idle. Normally, neither file should be
-changed when working on individual test modules. The third command runs
-unittest indirectly through regrtest. The same happens when the entire test
-suite is run with 'python -m test'. So that command must work for buildbots
-to stay green. Idle tests must not disturb the environment in a way that
-makes other tests fail (issue 18081).
+The idle tests are 'discovered' by
+idlelib.idle_test.__init__.load_tests, which is also imported into
+test.test_idle. Normally, neither file should be changed when working on
+individual test modules. The third command runs unittest indirectly
+through regrtest. The same happens when the entire test suite is run
+with 'python -m test'. So that command must work for buildbots to stay
+green. Idle tests must not disturb the environment in a way that makes
+other tests fail (issue 18081).
 
-To run an individual Testcase or test method, extend the dotted name given to
-unittest on the command line.
+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:
+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