Add unit tests for loopbacks; While here, fix a bug in get_by_name(), yaay

validator/test_loopback.py

@@ -0,0 +1,26 @@
+import unittest
+import yaml
+import validator.loopback as loopback
+
+class TestLoopbackMethods(unittest.TestCase):
+    def setUp(self):
+        with open("unittest/test_loopback.yaml", "r") as f:
+            self.cfg = yaml.load(f, Loader = yaml.FullLoader)
+
+    def test_get_by_name(self):
+        ifname, iface = loopback.get_by_name(self.cfg, "loop1")
+        self.assertIsNotNone(iface)
+        self.assertEqual("loop1", ifname)
+        self.assertEqual(iface['mtu'], 2000)
+
+        ifname, iface = loopback.get_by_name(self.cfg, "loop-noexist")
+        self.assertIsNone(ifname)
+        self.assertIsNone(iface)
+
+    def test_enumerators(self):
+        ifs = loopback.get_loopbacks(self.cfg)
+        self.assertEqual(len(ifs), 3)
+        self.assertIn("loop0", ifs)
+        self.assertIn("loop1", ifs)
+        self.assertIn("loop2", ifs)
+        self.assertNotIn("loop-noexist", ifs)