improve the command-line interface of json.tool (closes #21000)

A patch from Berker Peksag.

1 files changed, 8 insertions, 0 deletions

diff --git a/Lib/test/test_json/test_tool.py b/Lib/test/test_json/test_tool.py
index 0c39e56..5484a8a 100644
--- a/Lib/test/test_json/test_tool.py
+++ b/Lib/test/test_json/test_tool.py
@@ -55,6 +55,7 @@ class TestTool(unittest.TestCase):
     def test_infile_stdout(self):
         infile = self._create_infile()
         rc, out, err = assert_python_ok('-m', 'json.tool', infile)
+        self.assertEqual(rc, 0)
         self.assertEqual(out.splitlines(), self.expect.encode().splitlines())
         self.assertEqual(err, b'')
 
@@ -65,5 +66,12 @@ class TestTool(unittest.TestCase):
         self.addCleanup(os.remove, outfile)
         with open(outfile, "r") as fp:
             self.assertEqual(fp.read(), self.expect)
+        self.assertEqual(rc, 0)
         self.assertEqual(out, b'')
         self.assertEqual(err, b'')
+
+    def test_help_flag(self):
+        rc, out, err = assert_python_ok('-m', 'json.tool', '-h')
+        self.assertEqual(rc, 0)
+        self.assertTrue(out.startswith(b'usage: '))
+        self.assertEqual(err, b'')