Added test for poorly specified tags.

2 files changed, 10 insertions, 1 deletions

diff --git a/python/subunit/_output.py b/python/subunit/_output.py
index 24d63dc..66ff5df 100644
--- a/python/subunit/_output.py
+++ b/python/subunit/_output.py
@@ -150,12 +150,14 @@ def set_status_cb(option, opt_str, value, parser, status_name):
         raise OptionValueError("argument %s: Only one status may be specified at once." % option)
 
     if len(parser.rargs) == 0:
-        raise OptionValueError("argument %s: must specify a single TEST_ID.")
+        raise OptionValueError("argument %s: must specify a single TEST_ID." % option)
     parser.values.action = status_name
     parser.values.test_id = parser.rargs.pop(0)
 
 
 def set_tags_cb(option, opt_str, value, parser):
+    if not parser.rargs:
+        raise OptionValueError("Must specify at least one tag with --tags")
     parser.values.tags = parser.rargs.pop(0).split(',')
 
 
diff --git a/python/subunit/tests/test_output_filter.py b/python/subunit/tests/test_output_filter.py
index f3000ad..a31ae2b 100644
--- a/python/subunit/tests/test_output_filter.py
+++ b/python/subunit/tests/test_output_filter.py
@@ -187,6 +187,13 @@ class ArgParserTests(TestCaseWithPatchedStderr):
                 '--tags without a status command\n'))
         )
 
+    def test_must_specify_tags_with_tags_options(self):
+        fn = lambda: safe_parse_arguments(['--fail', 'foo', '--tags'])
+        self.assertThat(
+            fn,
+            raises(RuntimeError('subunit-output: error: Must specify at least one tag with --tags\n'))
+        )
+
 
 def get_result_for(commands):
     """Get a result object from *commands.