Suppresses stdout and stderr output by default when calling an application command from pyscript.

Added support for tab completing application commands in ipython shell
Updated unit tests scripts to set cmd_echo to True to validate command output.

Author: anselor

cmd2/pyscript_bridge.py

@@ -41,13 +41,15 @@ def __bool__(self):
 
 class CopyStream(object):
     """Copies all data written to a stream"""
-    def __init__(self, inner_stream):
+    def __init__(self, inner_stream, echo):
         self.buffer = ''
         self.inner_stream = inner_stream
+        self.echo = echo
 
     def write(self, s):
         self.buffer += s
-        self.inner_stream.write(s)
+        if self.echo:
+            self.inner_stream.write(s)
 
     def read(self):
         raise NotImplementedError
@@ -62,12 +64,12 @@ def __getattr__(self, item):
             return getattr(self.inner_stream, item)
 
 
-def _exec_cmd(cmd2_app, func):
+def _exec_cmd(cmd2_app, func, echo):
     """Helper to encapsulate executing a command and capturing the results"""
-    copy_stdout = CopyStream(sys.stdout)
-    copy_stderr = CopyStream(sys.stderr)
+    copy_stdout = CopyStream(sys.stdout, echo)
+    copy_stderr = CopyStream(sys.stderr, echo)
 
-    copy_cmd_stdout = CopyStream(cmd2_app.stdout)
+    copy_cmd_stdout = CopyStream(cmd2_app.stdout, echo)
 
     cmd2_app._last_result = None
 
@@ -80,7 +82,7 @@ def _exec_cmd(cmd2_app, func):
         cmd2_app.stdout = copy_cmd_stdout.inner_stream
 
     # if stderr is empty, set it to None
-    stderr = copy_stderr if copy_stderr.buffer else None
+    stderr = copy_stderr.buffer if copy_stderr.buffer else None
 
     outbuf = copy_cmd_stdout.buffer if copy_cmd_stdout.buffer else copy_stdout.buffer
     result = CommandResult(stdout=outbuf, stderr=stderr, data=cmd2_app._last_result)
@@ -91,7 +93,8 @@ class ArgparseFunctor:
     """
     Encapsulates translating python object traversal
     """
-    def __init__(self, cmd2_app, item, parser):
+    def __init__(self, echo: bool, cmd2_app, item, parser):
+        self._echo = echo
         self._cmd2_app = cmd2_app
         self._item = item
         self._parser = parser
@@ -101,6 +104,14 @@ def __init__(self, cmd2_app, item, parser):
         # argparse object for the current command layer
         self.__current_subcommand_parser = parser
 
+    def __dir__(self):
+        """Returns a custom list of attribute names to match the sub-commands"""
+        commands = []
+        for action in self.__current_subcommand_parser._actions:
+            if not action.option_strings and isinstance(action, argparse._SubParsersAction):
+                commands.extend(action.choices)
+        return commands
+
     def __getattr__(self, item):
         """Search for a subcommand matching this item and update internal state to track the traversal"""
         # look for sub-command under the current command/sub-command layer
@@ -114,7 +125,6 @@ def __getattr__(self, item):
                     return self
 
         raise AttributeError(item)
-        # return super().__getattr__(item)
 
     def __call__(self, *args, **kwargs):
         """
@@ -251,16 +261,16 @@ def traverse_parser(parser):
 
         traverse_parser(self._parser)
 
-        # print('Command: {}'.format(cmd_str[0]))
+        return _exec_cmd(self._cmd2_app, functools.partial(func, cmd_str[0]), self._echo)
 
-        return _exec_cmd(self._cmd2_app, functools.partial(func, cmd_str[0]))
 
 class PyscriptBridge(object):
     """Preserves the legacy 'cmd' interface for pyscript while also providing a new python API wrapper for
     application commands."""
     def __init__(self, cmd2_app):
         self._cmd2_app = cmd2_app
         self._last_result = None
+        self.cmd_echo = False
 
     def __getattr__(self, item: str):
         """Check if the attribute is a command. If so, return a callable."""
@@ -274,13 +284,19 @@ def __getattr__(self, item: str):
             except AttributeError:
                 # Command doesn't, we will accept parameters in the form of a command string
                 def wrap_func(args=''):
-                    return _exec_cmd(self._cmd2_app, functools.partial(func, args))
+                    return _exec_cmd(self._cmd2_app, functools.partial(func, args), self.cmd_echo)
                 return wrap_func
             else:
                 # Command does use argparse, return an object that can traverse the argparse subcommands and arguments
-                return ArgparseFunctor(self._cmd2_app, item, parser)
+                return ArgparseFunctor(self.cmd_echo, self._cmd2_app, item, parser)
 
-        raise AttributeError(item)
+        return super().__getattr__(item)
+
+    def __dir__(self):
+        """Return a custom set of attribute names to match the available commands"""
+        commands = list(self._cmd2_app.get_all_commands())
+        commands.insert(0, 'cmd_echo')
+        return commands
 
     def __call__(self, args):
-        return _exec_cmd(self._cmd2_app, functools.partial(self._cmd2_app.onecmd_plus_hooks, args + '\n'))
+        return _exec_cmd(self._cmd2_app, functools.partial(self._cmd2_app.onecmd_plus_hooks, args + '\n'), self.cmd_echo)

tests/pyscript/bar1.py

@@ -1 +1,2 @@
+app.cmd_echo = True
 app.bar('11', '22')

tests/pyscript/custom_echo.py

@@ -0,0 +1,2 @@
+custom.cmd_echo = True
+custom.echo('blah!')

tests/pyscript/foo1.py

@@ -1 +1,2 @@
+app.cmd_echo = True
 app.foo('aaa', 'bbb', counter=3, trueval=True, constval=True)

tests/pyscript/foo2.py

@@ -1 +1,2 @@
+app.cmd_echo = True
 app.foo('11', '22', '33', '44', counter=3, trueval=True, constval=True)

tests/pyscript/foo3.py

@@ -1 +1,2 @@
+app.cmd_echo = True
 app.foo('11', '22', '33', '44', '55', '66', counter=3, trueval=False, constval=False)

tests/pyscript/foo4.py

@@ -1,3 +1,4 @@
+app.cmd_echo = True
 result = app.foo('aaa', 'bbb', counter=3)
 out_text = 'Fail'
 if result:

tests/pyscript/help.py

@@ -1 +1,2 @@
-app.help()
+app.cmd_echo = True
+app.help()

tests/pyscript/help_media.py

@@ -1 +1,2 @@
+app.cmd_echo = True
 app.help('media')

tests/pyscript/media_movies_add1.py

@@ -1 +1,2 @@
+app.cmd_echo = True
 app.media.movies.add('My Movie', 'PG-13', director=('George Lucas', 'J. J. Abrams'))