cbuildbot_config: add a delete_key/delete_keys feature

BUG=chromium:433459
TEST=New unit test. Inspection of config dump diff.

Change-Id: Ia557a778a13c906d92033d045d73bdd2c32194f1
Reviewed-on: https://chromium-review.googlesource.com/231123
Reviewed-by: Yu-Ju Hong <yjhong@chromium.org>
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/cbuildbot/cbuildbot_config_unittest.py b/cbuildbot/cbuildbot_config_unittest.py
index b93fe623e..88d81c14e 100755
--- a/cbuildbot/cbuildbot_config_unittest.py
+++ b/cbuildbot/cbuildbot_config_unittest.py
@@ -65,6 +65,20 @@ class ConfigClassTest(cros_test_lib.TestCase):
 
     self.assertRaises(AttributeError, getattr, cfg, 'foobar')
 
+  # pylint: disable-msg=W0212
+  def testDeleteKey(self):
+    base_config = cbuildbot_config._config(foo='bar')
+    inherited_config = base_config.derive(foo=cbuildbot_config.delete_key())
+    self.assertTrue('foo' in base_config)
+    self.assertFalse('foo' in inherited_config)
+
+  def testDeleteKeys(self):
+    base_config = cbuildbot_config._config(foo='bar',
+                                           baz='bak')
+    inherited_config_1 = base_config.derive(qzr='flp')
+    inherited_config_2 = inherited_config_1.derive(
+        cbuildbot_config.delete_keys(base_config))
+    self.assertEqual(inherited_config_2, {'qzr': 'flp'})
 
 class CBuildBotTest(cros_test_lib.MoxTestCase):
   """General tests of cbuildbot_config with respect to cbuildbot."""