Add a few more tests for error cases in option parser.

2 files changed, 35 insertions, 11 deletions

diff --git a/python/subunit/_output.py b/python/subunit/_output.py
index 6f111cc..bdea14f 100644
--- a/python/subunit/_output.py
+++ b/python/subunit/_output.py
@@ -43,8 +43,9 @@ def parse_arguments(args=None, ParserClass=OptionParser):
     command-line arguments. This is useful for testing.
     """
     parser = ParserClass(
-        prog='subunit-output',
+        prog="subunit-output",
         description="A tool to generate a subunit v2 result byte-stream",
+        usage="subunit-output [-h] [status test_id] [options]",
     )
     parser.set_default('tags', None)
 
@@ -131,6 +132,8 @@ def parse_arguments(args=None, ParserClass=OptionParser):
                 parser.error("Cannot open %s (%s)" % (options.attach_file, e.strerror))
     if options.tags and not options.action:
         parser.error("Cannot specify --tags without a status command")
+    if not (options.attach_file or options.action):
+        parser.error("Must specify either --attach-file or a status command")
 
     return options
 
@@ -139,6 +142,8 @@ def status_action(option, opt_str, value, parser, status_name):
     if getattr(parser.values, "action", None) is not None:
         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.")
     parser.values.action = status_name
     parser.values.test_id = parser.rargs.pop(0)
 
diff --git a/python/subunit/tests/test_output_filter.py b/python/subunit/tests/test_output_filter.py
index 658174c..21d8172 100644
--- a/python/subunit/tests/test_output_filter.py
+++ b/python/subunit/tests/test_output_filter.py
@@ -52,7 +52,19 @@ class SafeOptionParser(optparse.OptionParser):
 safe_parse_arguments = partial(parse_arguments, ParserClass=SafeOptionParser)
 
 
-class TestStatusArgParserTests(WithScenarios, TestCase):
+class TestCaseWithPatchedStderr(TestCase):
+
+    def setUp(self):
+        super(TestCaseWithPatchedStderr, self).setUp()
+        # prevent OptionParser from printing to stderr:
+        if sys.version[0] > '2':
+            self._stderr = StringIO()
+        else:
+            self._stderr = BytesIO()
+        self.patch(optparse.sys, 'stderr', self._stderr)
+
+
+class TestStatusArgParserTests(WithScenarios, TestCaseWithPatchedStderr):
 
     scenarios = [
         (cmd, dict(command=cmd, option='--' + cmd)) for cmd in (
@@ -122,17 +134,16 @@ class TestStatusArgParserTests(WithScenarios, TestCase):
 
         self.assertThat(args.file_name, Equals("foo"))
 
+    def test_requires_test_id(self):
+        fn = lambda: safe_parse_arguments(args=[self.option])
+        self.assertThat(
+            fn,
+            raises(RuntimeError('subunit-output: error: argument %s: must '
+                'specify a single TEST_ID.\n'))
+        )
 
-class ArgParserTests(TestCase):
 
-    def setUp(self):
-        super(ArgParserTests, self).setUp()
-        # prevent OptionParser from printing to stderr:
-        if sys.version[0] > '2':
-            self._stderr = StringIO()
-        else:
-            self._stderr = BytesIO()
-        self.patch(optparse.sys, 'stderr', self._stderr)
+class ArgParserTests(TestCaseWithPatchedStderr):
 
     def test_can_parse_attach_file_without_test_id(self):
         with NamedTemporaryFile() as tmp_file:
@@ -141,6 +152,14 @@ class ArgParserTests(TestCase):
             )
             self.assertThat(args.attach_file.name, Equals(tmp_file.name))
 
+    def test_must_specify_argument(self):
+        fn = lambda: safe_parse_arguments([])
+        self.assertThat(
+            fn,
+            raises(RuntimeError('subunit-output: error: Must specify either '
+                '--attach-file or a status command\n'))
+        )
+
     def test_cannot_specify_more_than_one_status_command(self):
         fn = lambda: safe_parse_arguments(['--fail', 'foo', '--skip', 'bar'])
         self.assertThat(