Enhance entry addition process: implement immediate file save after adding an entry and handle save failure by removing the entry for improved reliability.

tests/test_manager.py

@@ -634,3 +634,58 @@ class TestHostsManager:
         finally:
             # Clean up
             Path(temp_path).unlink()
+
+    def test_add_entry_success(self):
+        """Test successfully adding an entry with immediate save."""
+        manager = HostsManager()
+        manager.edit_mode = True
+
+        # Mock the save operation to succeed
+        with patch.object(manager, "save_hosts_file") as mock_save:
+            mock_save.return_value = (True, "File saved successfully")
+
+            hosts_file = HostsFile()
+            test_entry = HostEntry(ip_address="192.168.1.100", hostnames=["testhost"])
+
+            success, message = manager.add_entry(hosts_file, test_entry)
+
+            assert success
+            assert "Entry added: testhost" in message
+            assert len(hosts_file.entries) == 1
+            assert hosts_file.entries[0] == test_entry
+            mock_save.assert_called_once_with(hosts_file)
+
+    def test_add_entry_save_failure(self):
+        """Test adding an entry when save fails."""
+        manager = HostsManager()
+        manager.edit_mode = True
+
+        # Mock the save operation to fail
+        with patch.object(manager, "save_hosts_file") as mock_save:
+            mock_save.return_value = (False, "Permission denied")
+
+            hosts_file = HostsFile()
+            test_entry = HostEntry(ip_address="192.168.1.100", hostnames=["testhost"])
+
+            success, message = manager.add_entry(hosts_file, test_entry)
+
+            assert not success
+            assert "Failed to save after adding entry" in message
+            assert (
+                len(hosts_file.entries) == 0
+            )  # Entry should be removed on save failure
+            mock_save.assert_called_once_with(hosts_file)
+
+    def test_add_entry_not_in_edit_mode(self):
+        """Test adding an entry when not in edit mode."""
+        manager = HostsManager()
+        # edit_mode defaults to False
+
+        hosts_file = HostsFile()
+        test_entry = HostEntry(ip_address="192.168.1.100", hostnames=["testhost"])
+
+        success, message = manager.add_entry(hosts_file, test_entry)
+
+        assert not success
+        assert "Not in edit mode" in message
+        assert len(hosts_file.entries) == 0