Error out for remaining args in custom commands

awscli/clidriver.py

@@ -194,6 +194,7 @@ def main(self, args=None):
             self._handle_top_level_args(parsed_args)
             return command_table[parsed_args.command](remaining, parsed_args)
         except UnknownArgumentError as e:
+            sys.stderr.write("\n")
             sys.stderr.write(str(e) + '\n')
             return 255
         except NoRegionError as e:

awscli/customizations/commands.py

@@ -176,6 +176,8 @@ def __call__(self, args, parsed_globals):
         elif getattr(parsed_args, 'subcommand', None) is None:
             # No subcommand was specified so call the main
             # function for this top level command.
+            if remaining:
+                raise ValueError("Unknown options: %s" % ','.join(remaining))
             return self._run_main(parsed_args, parsed_globals)
         else:
             return subcommand_table[parsed_args.subcommand](remaining,

tests/unit/customizations/s3/test_ls_command.py

@@ -14,6 +14,7 @@
 from awscli.testutils import BaseAWSCommandParamsTest
 from dateutil import parser, tz
 
+
 class TestLSCommand(BaseAWSCommandParamsTest):
 
     def test_operations_used_in_recursive_list(self):
@@ -34,6 +35,7 @@ def test_operations_used_in_recursive_list(self):
         self.assertEqual(
             stdout, '%s        100 foo/bar.txt\n'%time_local.strftime('%Y-%m-%d %H:%M:%S'))
 
-
-if __name__ == "__main__":
-    unittest.main()
+    def test_errors_out_with_extra_arguments(self):
+        stderr = self.run_cmd('s3 ls --extra-argument-foo', expected_rc=255)[1]
+        self.assertIn('Unknown options', stderr)
+        self.assertIn('--extra-argument-foo', stderr)