Find correct source for extended commands (#254)

Author: stefanv

spin/cmds/meta.py

@@ -29,7 +29,11 @@ def introspect(*, cmd):
 
     cmd_func = cmds[cmd]
     try:
-        code = inspect.getsource(cmd_func.callback)
+        if hasattr(cmd_func.callback, "_parent"):
+            # `util.extend_command` was used
+            code = inspect.getsource(cmd_func.callback._parent)
+        else:
+            code = inspect.getsource(cmd_func.callback)
     except TypeError:
         # Perhaps a partial, try again
         code = inspect.getsource(cmd_func.callback.func)

spin/cmds/util.py

@@ -160,6 +160,7 @@ def parent_cmd(*user_args, **user_kwargs):
             return user_func(*args, parent_callback=parent_cmd, **kwargs)
 
         my_cmd.callback = click.pass_context(callback_with_parent_callback)
+        my_cmd.callback._parent = user_func
 
         if doc is not None:
             my_cmd.help = doc