Added get_domain function

tests/unit/test_get_domain_filter.py

@@ -0,0 +1,69 @@
+# tests/unit/test_get_domain_filter.py
+import unittest
+import sys
+import os
+
+# Ensure filter_plugins directory is on the path
+sys.path.insert(
+    0,
+    os.path.abspath(
+        os.path.join(os.path.dirname(__file__), '../../filter_plugins')
+    )
+)
+
+from get_domain_filter import FilterModule
+from ansible.errors import AnsibleFilterError
+
+class TestGetDomainFilter(unittest.TestCase):
+    def setUp(self):
+        # Retrieve the get_domain filter function
+        self.get_domain = FilterModule().filters()['get_domain']
+
+    def test_string_value(self):
+        domains = {'app': 'example.com'}
+        self.assertEqual(self.get_domain(domains, 'app'), 'example.com')
+
+    def test_dict_value(self):
+        domains = {'app': {'primary': 'primary.com', 'secondary': 'secondary.com'}}
+        self.assertEqual(self.get_domain(domains, 'app'), 'primary.com')
+
+    def test_list_value(self):
+        domains = {'app': ['first.com', 'second.com']}
+        self.assertEqual(self.get_domain(domains, 'app'), 'first.com')
+
+    def test_missing_application_id(self):
+        domains = {'app': 'example.com'}
+        with self.assertRaises(AnsibleFilterError):
+            self.get_domain(domains, 'missing')
+
+    def test_domains_not_dict(self):
+        with self.assertRaises(AnsibleFilterError):
+            self.get_domain(['not', 'a', 'dict'], 'app')
+
+    def test_empty_string(self):
+        domains = {'app': ''}
+        with self.assertRaises(AnsibleFilterError):
+            self.get_domain(domains, 'app')
+
+    def test_empty_dict(self):
+        domains = {'app': {}}
+        with self.assertRaises(AnsibleFilterError):
+            self.get_domain(domains, 'app')
+
+    def test_empty_list(self):
+        domains = {'app': []}
+        with self.assertRaises(AnsibleFilterError):
+            self.get_domain(domains, 'app')
+
+    def test_non_string_in_dict(self):
+        domains = {'app': {'key': 123}}
+        with self.assertRaises(AnsibleFilterError):
+            self.get_domain(domains, 'app')
+
+    def test_non_string_in_list(self):
+        domains = {'app': [123]}
+        with self.assertRaises(AnsibleFilterError):
+            self.get_domain(domains, 'app')
+
+if __name__ == '__main__':
+    unittest.main()