# HG changeset patch
# User John Mulligan <phlogistonjohn@asynchrono.us>
# Date 1257119230 18000
#      Sun Nov 01 18:47:10 2009 -0500
# Node ID 639b5a7f1ff64826da4b0f6be1ddd1ceeead2d53
# Parent  8f477e723d7ca5b73948efd20c3e8dfb04b5eb4f
commander: specific error for mismatched args

diff --git a/test/test_cli_commands.py b/test/test_cli_commands.py
--- a/test/test_cli_commands.py
+++ b/test/test_cli_commands.py
@@ -216,7 +216,6 @@
             commander.main(GOPT_A, CMDTABLE_A, arguments))
 
     def test_main_dispatch_special(self):
-        sys.stderr = StringIO.StringIO()
         try:
             commander.main(GOPT_A, CMDTABLE_A, 'foo -h'.split())
             caught = False
@@ -236,6 +235,15 @@
             caught = True
         self.assertTrue(caught)
 
+    def test_main_dispatch_badargs(self):
+        try:
+            commander.main(GOPT_A, CMDTABLE_A, 'foo x y z'.split())
+            caught = False
+        except:
+            caught = True
+        self.assertTrue(caught)
+        
+
 
             
 class Capture(list):
diff --git a/vanity/commander.py b/vanity/commander.py
--- a/vanity/commander.py
+++ b/vanity/commander.py
@@ -19,6 +19,7 @@
 
 from vanity import cli
 import sys
+import traceback
 
 
 class InvalidCommand(cli.CliError):
@@ -49,6 +50,13 @@
         self.args = args
 
 
+class InvalidArguments(cli.CliError):
+    """The user failed to give correct number of args"""
+    def __init__(self, name):
+        cli.CliError.__init__(self,
+            '%s: unexpected number of arguments' % name)
+
+
 def main(globalopts, cmdtable, arguments, generichelp=None):
     """Launch a subcommand based on the given arguments, automatically
     handling help and cli parsing errors. Will return the
@@ -207,7 +215,12 @@
         self.strict = strict
 
     def __call__(self, opts, args):
-        return self.target(*args, **opts)
+        try:
+            return self.target(*args, **opts)
+        except TypeError, err:
+            if len(traceback.extract_tb(sys.exc_info()[2])) == 1:
+                raise InvalidArguments(self.name)
+            raise
 
     def aliaslist(self):
         """Return a list of command aliases.