enable test for callable object usage

PiperOrigin-RevId: 260045817
Change-Id: I700cef5d0676fae7c79221beafcf07373f268a46

Author: dbieber

fire/helptext.py

@@ -498,7 +498,10 @@ def UsageText(component, trace=None, verbose=False):
 
   if callable(component):
     callable_items = _GetCallableUsageItems(spec, metadata)
-    continuations.append(' '.join(callable_items))
+    if callable_items:
+      continuations.append(' '.join(callable_items))
+    elif trace:
+      continuations.append(trace.separator)
     availability_lines.extend(_GetCallableAvailabilityLines(spec))
 
   if continuations:

fire/helptext_test.py

@@ -355,18 +355,16 @@ def testUsageOutputFunctionWithDocstring(self):
         textwrap.dedent(expected_output).lstrip('\n'),
         usage_output)
 
-  @testutils.skip('The functionality is not implemented yet')
   def testUsageOutputCallable(self):
-    # This is both a group and a command!
-    component = tc.CallableWithKeywordArgument
-    t = trace.FireTrace(component, name='CallableWithKeywordArgument')
-    usage_output = helptext.UsageText(component, trace=t, verbose=True)
-    # TODO(joejoevictor): We need to handle the case for keyword args as well
-    # i.e. __call__ method of CallableWithKeywordArgument
+    # This is both a group and a command.
+    component = tc.CallableWithKeywordArgument()
+    t = trace.FireTrace(component, name='CallableWithKeywordArgument',
+                        separator='@')
+    usage_output = helptext.UsageText(component, trace=t, verbose=False)
     expected_output = '''
-    Usage: CallableWithKeywordArgument <command>
-
-      Available commands:    print_msg
+    Usage: CallableWithKeywordArgument <command> | <flags>
+      available commands:    print_msg
+      flags are accepted
 
     For detailed information on this command, run:
       CallableWithKeywordArgument -- --help'''

fire/inspectutils.py

@@ -86,6 +86,16 @@ class with an __init__ method.
   return fn, skip_arg
 
 
+def Py2GetArgSpec(fn):
+  """A wrapper around getargspec that tries both fn and fn.__call__."""
+  try:
+    return inspect.getargspec(fn)  # pylint: disable=deprecated-method
+  except TypeError:
+    if hasattr(fn, '__call__'):
+      return inspect.getargspec(fn.__call__)  # pylint: disable=deprecated-method
+    raise
+
+
 def GetFullArgSpec(fn):
   """Returns a FullArgSpec describing the given callable."""
 
@@ -94,7 +104,7 @@ def GetFullArgSpec(fn):
 
   try:
     if six.PY2:
-      args, varargs, varkw, defaults = inspect.getargspec(fn)  # pylint: disable=deprecated-method
+      args, varargs, varkw, defaults = Py2GetArgSpec(fn)
       kwonlyargs = kwonlydefaults = None
       annotations = getattr(fn, '__annotations__', None)
     else:

fire/test_components.py

@@ -336,6 +336,9 @@ def print_msg(self, msg):
     print(msg)
 
 
+callable_with_keyword_argument = CallableWithKeywordArgument()
+
+
 class ClassWithDocstring(object):
   """Test class for testing help text output.