Fixed transcript testing issues

Transcript testing no longer creates an unnecessary 2nd instance of the class derived from cmd2.Cmd.  This dramatically simplifies transcript testing for derived classes which have required parameters during construction.

As a side effect the, feedback_to_output attribute now defaults to false.  This had some minor ripple effects on various unit tests.

Author: Todd Leonhardt

cmd2.py

@@ -618,7 +618,7 @@ class Cmd(cmd.Cmd):
             for editor in ['vim', 'vi', 'emacs', 'nano', 'pico', 'gedit', 'kate', 'subl', 'geany', 'atom']:
                 if _which(editor):
                     break
-    feedback_to_output = False  # Do include nonessentials in >, | output
+    feedback_to_output = True  # Do include nonessentials in >, | output
     locals_in_py = True
     quiet = False  # Do not suppress nonessential output
     timing = False  # Prints elapsed time for each command
@@ -1691,7 +1691,7 @@ def run_transcript_tests(self, callargs):
         :param callargs: List[str] - list of transcript test file names
         """
         class TestMyAppCase(Cmd2TestCase):
-            CmdApp = self.__class__
+            cmdapp = self
 
         self.__class__.testfiles = callargs
         sys.argv = [sys.argv[0]]  # the --test argument upsets unittest.main()
@@ -1731,12 +1731,12 @@ def cmdloop(self, intro=None):
             if callopts.test:
                 self._transcript_files = callargs
 
+        # Always run the preloop first
+        self.preloop()
+
         if self._transcript_files is not None:
             self.run_transcript_tests(self._transcript_files)
         else:
-            # Always run the preloop first
-            self.preloop()
-
             # If an intro was supplied in the method call, allow it to override the default
             if intro is not None:
                 self.intro = intro
@@ -1754,8 +1754,8 @@ def cmdloop(self, intro=None):
             if not stop:
                 self._cmdloop()
 
-            # Run the postloop() no matter what
-            self.postloop()
+        # Run the postloop() no matter what
+        self.postloop()
 
 
 class HistoryItem(str):
@@ -1960,25 +1960,11 @@ def restore(self):
                 setattr(self.obj, attrib, getattr(self, attrib))
 
 
-class Borg(object):
-    """All instances of any Borg subclass will share state.
-    from Python Cookbook, 2nd Ed., recipe 6.16"""
-    _shared_state = {}
-
-    def __new__(cls, *a, **k):
-        obj = object.__new__(cls)
-        obj.__dict__ = cls._shared_state
-        return obj
-
-
-class OutputTrap(Borg):
-    """Instantiate  an OutputTrap to divert/capture ALL stdout output.  For use in unit testing.
-    Call `tearDown()` to return to normal output."""
+class OutputTrap(object):
+    """Instantiate an OutputTrap to divert/capture ALL stdout output.  For use in transcript testing."""
 
     def __init__(self):
         self.contents = ''
-        self.old_stdout = sys.stdout
-        sys.stdout = self
 
     def write(self, txt):
         """Add text to the internal contents.
@@ -1996,17 +1982,12 @@ def read(self):
         self.contents = ''
         return result
 
-    def tear_down(self):
-        """Restores normal output."""
-        sys.stdout = self.old_stdout
-        self.contents = ''
-
 
 class Cmd2TestCase(unittest.TestCase):
     """Subclass this, setting CmdApp, to make a unittest.TestCase class
        that will execute the commands in a transcript file and expect the results shown.
        See example.py"""
-    CmdApp = None
+    cmdapp = None
     regexPattern = pyparsing.QuotedString(quoteChar=r'/', escChar='\\', multiline=True, unquoteResults=True)
     regexPattern.ignore(pyparsing.cStyleComment)
     notRegexPattern = pyparsing.Word(pyparsing.printables)
@@ -2016,7 +1997,7 @@ class Cmd2TestCase(unittest.TestCase):
 
     def fetchTranscripts(self):
         self.transcripts = {}
-        for fileset in self.CmdApp.testfiles:
+        for fileset in self.cmdapp.testfiles:
             for fname in glob.glob(fileset):
                 tfile = open(fname)
                 self.transcripts[fname] = iter(tfile.readlines())
@@ -2025,17 +2006,15 @@ def fetchTranscripts(self):
             raise Exception("No test files found - nothing to test.")
 
     def setUp(self):
-        if self.CmdApp:
-            self.outputTrap = OutputTrap()
-            self.cmdapp = self.CmdApp()
+        if self.cmdapp:
             self.fetchTranscripts()
 
-            # Make sure any required initialization gets done and flush the output buffer
-            self.cmdapp.preloop()
-            self.outputTrap.read()
+            # Trap stdout
+            self._orig_stdout = self.cmdapp.stdout
+            self.cmdapp.stdout = OutputTrap()
 
     def runTest(self):  # was testall
-        if self.CmdApp:
+        if self.cmdapp:
             its = sorted(self.transcripts.items())
             for (fname, transcript) in its:
                 self._test_transcript(fname, transcript)
@@ -2071,7 +2050,7 @@ def _test_transcript(self, fname, transcript):
             # Send the command into the application and capture the resulting output
             # TODO: Should we get the return value and act if stop == True?
             self.cmdapp.onecmd_plus_hooks(command)
-            result = self.outputTrap.read()
+            result = self.cmdapp.stdout.read()
             # Read the expected result from transcript
             if line.startswith(self.cmdapp.prompt):
                 message = '\nFile %s, line %d\nCommand was:\n%r\nExpected: (nothing)\nGot:\n%r\n' % \
@@ -2098,11 +2077,9 @@ def _test_transcript(self, fname, transcript):
             self.assertTrue(re.match(expected, result, re.MULTILINE | re.DOTALL), message)
 
     def tearDown(self):
-        if self.CmdApp:
-            # Make sure any required cleanup gets done
-            self.cmdapp.postloop()
-
-            self.outputTrap.tear_down()
+        if self.cmdapp:
+            # Restore stdout
+            self.cmdapp.stdout = self._orig_stdout
 
 
 def namedtuple_with_two_defaults(typename, field_names, default_values=('', '')):

tests/conftest.py

@@ -55,7 +55,7 @@
 default_file_name: command.txt
 echo: False
 editor: vim
-feedback_to_output: False
+feedback_to_output: True
 locals_in_py: True
 prompt: (Cmd)
 quiet: False
@@ -75,7 +75,7 @@
 default_file_name: command.txt # for ``save``, ``load``, etc.
 echo: False                    # Echo command issued into output
 editor: vim                    # Program used by ``edit``
-feedback_to_output: False      # include nonessentials in `|`, `>` results
+feedback_to_output: True       # include nonessentials in `|`, `>` results
 locals_in_py: True             # Allow access to your application in py via self
 prompt: (Cmd)                  # The prompt issued to solicit input
 quiet: False                   # Don't print nonessential feedback

tests/test_cmd2.py

@@ -266,16 +266,15 @@ def test_base_relative_load(base_app, request):
     assert out == expected
 
 
-def test_base_save(base_app, capsys):
+def test_base_save(base_app):
     # TODO: Use a temporary directory for the file
     filename = 'deleteme.txt'
     run_cmd(base_app, 'help')
     run_cmd(base_app, 'help save')
 
     # Test the * form of save which saves all commands from history
-    run_cmd(base_app, 'save * {}'.format(filename))
-    out, err = capsys.readouterr()
-    assert out == 'Saved to {}\n'.format(filename)
+    out = run_cmd(base_app, 'save * {}'.format(filename))
+    assert out == normalize('Saved to {}\n'.format(filename))
     expected = normalize("""
 help
 
@@ -288,18 +287,16 @@ def test_base_save(base_app, capsys):
     assert content == expected
 
     # Test the N form of save which saves a numbered command from history
-    run_cmd(base_app, 'save 1 {}'.format(filename))
-    out, err = capsys.readouterr()
-    assert out == 'Saved to {}\n'.format(filename)
+    out = run_cmd(base_app, 'save 1 {}'.format(filename))
+    assert out == normalize('Saved to {}\n'.format(filename))
     expected = normalize('help')
     with open(filename) as f:
         content = normalize(f.read())
     assert content == expected
 
     # Test the blank form of save which saves the most recent command from history
-    run_cmd(base_app, 'save {}'.format(filename))
-    out, err = capsys.readouterr()
-    assert out == 'Saved to {}\n'.format(filename)
+    out = run_cmd(base_app, 'save {}'.format(filename))
+    assert out == normalize('Saved to {}\n'.format(filename))
     expected = normalize('save 1 {}'.format(filename))
     with open(filename) as f:
         content = normalize(f.read())
@@ -397,6 +394,7 @@ def test_send_to_paste_buffer(base_app):
 
 
 def test_base_timing(base_app, capsys):
+    base_app.feedback_to_output = False
     out = run_cmd(base_app, 'set timing True')
     expected = normalize("""timing - was: False
 now: True

tests/test_transcript.py

@@ -149,6 +149,7 @@ def test_base_with_transcript(_cmdline_app):
 -------------------------[6]
 say -ps --repeat=5 goodnight, Gracie
 (Cmd) run 4
+say -ps --repeat=5 goodnight, Gracie
 OODNIGHT, GRACIEGAY
 OODNIGHT, GRACIEGAY
 OODNIGHT, GRACIEGAY

tests/transcript_regex.txt

@@ -10,7 +10,7 @@ debug: False
 default_file_name: command.txt
 echo: False
 editor: /([^\s]+)/
-feedback_to_output: False
+feedback_to_output: True
 locals_in_py: True
 maxrepeats: 3
 prompt: (Cmd)