1 files changed, 70 insertions, 0 deletions
diff --git a/src/tests/test_config_diff.py b/src/tests/test_config_diff.py
new file mode 100644
index 000000000..f61cbc4a2
--- /dev/null
+++ b/src/tests/test_config_diff.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2023 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import os
+import vyos.configtree
+
+from unittest import TestCase
+
+class TestConfigDiff(TestCase):
+    def setUp(self):
+        with open('tests/data/config.left', 'r') as f:
+            config_string = f.read()
+            self.config_left = vyos.configtree.ConfigTree(config_string)
+
+        with open('tests/data/config.right', 'r') as f:
+            config_string = f.read()
+            self.config_right = vyos.configtree.ConfigTree(config_string)
+
+        self.config_null = vyos.configtree.ConfigTree('')
+
+    def test_unit(self):
+        diff = vyos.configtree.DiffTree(self.config_left, self.config_null)
+        sub = diff.sub
+        self.assertEqual(sub.to_string(), self.config_left.to_string())
+
+        diff = vyos.configtree.DiffTree(self.config_null, self.config_left)
+        add = diff.add
+        self.assertEqual(add.to_string(), self.config_left.to_string())
+
+    def test_symmetry(self):
+        lr_diff = vyos.configtree.DiffTree(self.config_left,
+                                           self.config_right)
+        rl_diff = vyos.configtree.DiffTree(self.config_right,
+                                           self.config_left)
+
+        sub = lr_diff.sub
+        add = rl_diff.add
+        self.assertEqual(sub.to_string(), add.to_string())
+        add = lr_diff.add
+        sub = rl_diff.sub
+        self.assertEqual(add.to_string(), sub.to_string())
+
+    def test_identity(self):
+        lr_diff = vyos.configtree.DiffTree(self.config_left,
+                                           self.config_right)
+
+        sub = lr_diff.sub
+        inter = lr_diff.inter
+        add = lr_diff.add
+
+        r_union = vyos.configtree.union(add, inter)
+        l_union = vyos.configtree.union(sub, inter)
+
+        self.assertEqual(r_union.to_string(),
+                         self.config_right.to_string(ordered_values=True))
+        self.assertEqual(l_union.to_string(),
+                         self.config_left.to_string(ordered_values=True))