[dconf: 3/4] tests: Add a simple test case for help and update.

[Philip Withnall <pwithnall src gnome org>]

commit 50e95fbf8b35526fb962393813ed74806b70c187
Author: Tomasz Miąsko <tomasz miasko gmail com>
Date:   Mon Jan 7 00:00:00 2019 +0000

    tests: Add a simple test case for help and update.

 tests/test-dconf.py | 12 ++++++++++++
 1 file changed, 12 insertions(+)
---
diff --git a/tests/test-dconf.py b/tests/test-dconf.py
index aa04ec7..51e522b 100755
--- a/tests/test-dconf.py
+++ b/tests/test-dconf.py
@@ -237,6 +237,9 @@ class DBusTest(unittest.TestCase):
             ['write', '/key', 'not-a-gvariant-value'],
             # Too many arguments:
             ['write', '/key', '1', '2'],
+
+            # Too many arguments:
+            ['update', 'a', 'b'],
         ]
 
         for args in cases:
@@ -245,6 +248,15 @@ class DBusTest(unittest.TestCase):
                     dconf(*args, stderr=subprocess.PIPE)
                 self.assertRegex(cm.exception.stderr, 'Usage:')
 
+    def test_help(self):
+        """Help show usage information on stdout and exits with success."""
+
+        stdout = dconf('help', 'write').stdout
+        self.assertRegex(stdout, 'dconf write KEY VALUE')
+
+        stdout = dconf('help', 'help').stdout
+        self.assertRegex(stdout, 'dconf help COMMAND')
+
     def test_read_nonexisiting(self):
         """Reading missing key produces no output. """