Fixed issue where a ns_provider could be passed None instead of its correct cmd2.Cmd or CommandSet value.

Author: kmvanbrunt

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.3.2 (November 22, 2021)
+* Bug Fixes
+  * Fixed issue where a `ns_provider` could be passed `None` instead of its correct `cmd2.Cmd` or `CommandSet` value.
+
 ## 2.3.1 (November 18, 2021)
 * Bug Fixes
   * Fixed issue introduced in 2.3.0 with `AlternatingTable`, `BorderedTable`, and `SimpleTable` that caused

cmd2/cmd2.py

@@ -5418,7 +5418,6 @@ def _resolve_func_self(
 
         :param cmd_support_func: command support function. This could be a completer or namespace provider
         :param cmd_self: The `self` associated with the command or subcommand
-        :return:
         """
         # figure out what class the command support function was defined in
         func_class: Optional[Type[Any]] = get_defining_class(cmd_support_func)

cmd2/decorators.py

@@ -276,9 +276,9 @@ def with_argparser(
     with the given instance of argparse.ArgumentParser.
 
     :param parser: unique instance of ArgumentParser
-    :param ns_provider: An optional function that accepts a cmd2.Cmd object as an argument and returns an
-                        argparse.Namespace. This is useful if the Namespace needs to be prepopulated with
-                        state data that affects parsing.
+    :param ns_provider: An optional function that accepts a cmd2.Cmd or cmd2.CommandSet object as an argument and returns an
+                        argparse.Namespace. This is useful if the Namespace needs to be prepopulated with state data that
+                        affects parsing.
     :param preserve_quotes: if ``True``, then arguments passed to argparse maintain their quotes
     :param with_unknown_args: if true, then capture unknown args
     :return: function that gets passed argparse-parsed args in a ``Namespace``
@@ -351,7 +351,7 @@ def cmd_wrapper(*args: Any, **kwargs: Dict[str, Any]) -> Optional[bool]:
                 # functions are registered with the command argparser before anything is instantiated, we
                 # need to find an instance at runtime that matches the types during declaration
                 provider_self = cmd2_app._resolve_func_self(ns_provider, args[0])
-                namespace = ns_provider(provider_self if not None else cmd2_app)
+                namespace = ns_provider(provider_self if provider_self is not None else cmd2_app)
 
             try:
                 new_args: Union[Tuple[argparse.Namespace], Tuple[argparse.Namespace, List[str]]]

tests_isolated/test_commandset/test_commandset.py

@@ -1104,3 +1104,46 @@ def __init__(self):
                 settable_attrib_name='some_value',
             )
         )
+
+
+class NsProviderSet(cmd2.CommandSet):
+    # CommandSet which implements a namespace provider
+    def __init__(self, dummy):
+        # Use dummy argument so this won't be autoloaded by other tests
+        super(NsProviderSet, self).__init__()
+
+    def ns_provider(self) -> argparse.Namespace:
+        ns = argparse.Namespace()
+        # Save what was passed as self from with_argparser().
+        ns.self = self
+        return ns
+
+
+class NsProviderApp(cmd2.Cmd):
+    # Used to test namespace providers in CommandSets
+    def __init__(self, *args, **kwargs) -> None:
+        super().__init__(*args, **kwargs)
+        super(NsProviderApp, self).__init__(*args, **kwargs)
+
+    @cmd2.with_argparser(cmd2.Cmd2ArgumentParser(), ns_provider=NsProviderSet.ns_provider)
+    def do_test_ns(self, args: argparse.Namespace) -> None:
+        # Save args.self so the unit tests can read it.
+        self.last_result = args.self
+
+
+def test_ns_provider():
+    """This exercises code in with_argparser() decorator that calls namespace providers"""
+    ns_provider_set = NsProviderSet(1)
+    app = NsProviderApp(auto_load_commands=False)
+
+    # First test the case in which a namespace provider function resides in a CommandSet class which is registered.
+    # with_argparser() will pass the CommandSet instance to the ns_provider() function.
+    app.register_command_set(ns_provider_set)
+    run_cmd(app, "test_ns")
+    assert app.last_result == ns_provider_set
+
+    # Now test the case in which a namespace provider function resides in a CommandSet class which is not registered.
+    # with_argparser() will receive None from cmd2.Cmd._resolve_func_self() and therefore pass app as self to ns_provider().
+    app.unregister_command_set(ns_provider_set)
+    run_cmd(app, "test_ns")
+    assert app.last_result == app