Add management header to hosts files and enhance serialization formatting; update tests to reflect changes.

tests/test_parser.py

@@ -168,7 +168,12 @@ class TestHostsParser:
         parser = HostsParser()
         content = parser.serialize(hosts_file)
 
-        expected = """127.0.0.1\tlocalhost
+        expected = """# #
+# Host Database
+#
+# Managed by hosts - https://git.s1q.dev/phg/hosts
+# #
+127.0.0.1\tlocalhost
 192.168.1.1\trouter
 """
         assert content == expected
@@ -198,6 +203,7 @@ class TestHostsParser:
         
         expected = """# Header comment 1
 # Header comment 2
+# Managed by hosts - https://git.s1q.dev/phg/hosts
 127.0.0.1\tlocalhost\t# Loopback
 # 10.0.0.1\ttest
 
@@ -211,7 +217,13 @@ class TestHostsParser:
         parser = HostsParser()
         content = parser.serialize(hosts_file)
         
-        assert content == "\n"
+        expected = """# #
+# Host Database
+#
+# Managed by hosts - https://git.s1q.dev/phg/hosts
+# #
+"""
+        assert content == expected
     
     def test_write_hosts_file(self):
         """Test writing hosts file to disk."""
@@ -226,7 +238,14 @@ class TestHostsParser:
             # Read back and verify
             with open(f.name, 'r') as read_file:
                 content = read_file.read()
-                assert content == "127.0.0.1\tlocalhost\n"
+                expected = """# #
+# Host Database
+#
+# Managed by hosts - https://git.s1q.dev/phg/hosts
+# #
+127.0.0.1\tlocalhost
+"""
+                assert content == expected
         
         os.unlink(f.name)
     
@@ -259,7 +278,14 @@ class TestHostsParser:
             # Check new content
             with open(f.name, 'r') as new_file:
                 new_content = new_file.read()
-                assert new_content == "127.0.0.1\tlocalhost\n"
+                expected = """# #
+# Host Database
+#
+# Managed by hosts - https://git.s1q.dev/phg/hosts
+# #
+127.0.0.1\tlocalhost
+"""
+                assert new_content == expected
             
             # Cleanup
             os.unlink(backup_path)