feat: handle HEAD requests

stapler/handlers.py

@@ -153,7 +153,8 @@ class BaseHandler(abc.ABC, http.server.BaseHTTPRequestHandler):
         self.send_header("Content-Length", str(len(encoded)))
         self.send_header("Connection", "close")
         self.end_headers()
-        self.wfile.write(encoded)
+        if self.command != http.HTTPMethod.HEAD:
+            self.wfile.write(encoded)
         self.close_connection = True
 
     def send_status_only(
@@ -222,7 +223,7 @@ class BaseHandler(abc.ABC, http.server.BaseHTTPRequestHandler):
         self.send_header("Content-Length", str(out_size := len(response.content)))
         self.send_header("Connection", "close")
         self.end_headers()
-        if out_size > 0:
+        if out_size > 0 and self.command != http.HTTPMethod.HEAD:
             self.wfile.write(response.content)
         self.close_connection = True
 
@@ -387,9 +388,13 @@ class RequestHandler(http.server.SimpleHTTPRequestHandler, BaseHandler):
     def do_HEAD(self) -> None:
         with self.handle_errors():
             self._pre_log_request()
-            if not self._proxy_or_redirect():
+            if self._proxy_or_redirect():
-                super().do_HEAD()
+                return None
+            if self.path == "/" and self.host == self.default_host:
+                return self.send_basic_body(self.server_signature())
+            super().do_HEAD()
             self.close_connection = True
+            return None
 
     @typing.override
     def do_GET(self) -> None:

tests/test_handlers.py

@@ -36,6 +36,7 @@ class BaseHandlerTestCase(BaseTestCase, abc.ABC):
         code: int,
         message: str | None = None,
         headers: dict[str, str] | None = None,
+        content_length: int = 0,
     ) -> typing.Iterator[None]:
         if headers is None:
             headers = {}
@@ -46,7 +47,7 @@ class BaseHandlerTestCase(BaseTestCase, abc.ABC):
         send_response_mock.assert_called_once_with(code, message)
         send_header_mock.assert_has_calls(
             [
-                unittest.mock.call("Content-Length", "0"),
+                unittest.mock.call("Content-Length", str(content_length)),
             ]
             + [unittest.mock.call(header, value) for header, value in headers.items()],
             any_order=True,
@@ -192,9 +193,21 @@ class TestRequestHandler(BaseHandlerTestCase):
                 token_manager=self.token_manager,
             )
 
-    def test_do_head_forward(self) -> None:
+    def test_do_head_index(self) -> None:
         handler = self._get_handler()
         with (
+            self.expects_status_only(
+                handler, 200, content_length=len(handler.server_signature())
+            ),
+            self.patch("http.server.SimpleHTTPRequestHandler.do_HEAD", count=0),
+            self.seal_mocks(),
+        ):
+            handler.do_HEAD()
+
+    def test_do_head_forward(self) -> None:
+        handler = self._get_handler("/file")
+        with (
+            self.mock_call(self.registry.get_from_path, ["file"], Page("file")),
             self.patch("http.server.SimpleHTTPRequestHandler.do_HEAD"),
             self.seal_mocks(),
         ):