Refactor _static_request_handler (#2533)

Co-authored-by: Adam Hopkins <adam@amhopkins.com>

sanic/mixins/routes.py

@@ -1,12 +1,12 @@
 from ast import NodeVisitor, Return, parse
 from contextlib import suppress
+from email.utils import formatdate
 from functools import partial, wraps
 from inspect import getsource, signature
 from mimetypes import guess_type
 from os import path
 from pathlib import Path, PurePath
 from textwrap import dedent
-from time import gmtime, strftime
 from typing import (
     Any,
     Callable,
@@ -31,7 +31,7 @@ from sanic.handlers import ContentRangeHandler
 from sanic.log import error_logger
 from sanic.models.futures import FutureRoute, FutureStatic
 from sanic.models.handler_types import RouteHandler
-from sanic.response import HTTPResponse, file, file_stream
+from sanic.response import HTTPResponse, file, file_stream, validate_file
 from sanic.types import HashableDict
 
 
@@ -790,24 +790,9 @@ class RouteMixin(metaclass=SanicMeta):
 
         return name
 
-    async def _static_request_handler(
-        self,
-        file_or_directory,
-        use_modified_since,
-        use_content_range,
-        stream_large_files,
-        request,
-        content_type=None,
-        __file_uri__=None,
-    ):
-        # Merge served directory and requested file if provided
+    async def _get_file_path(self, file_or_directory, __file_uri__, not_found):
         file_path_raw = Path(unquote(file_or_directory))
         root_path = file_path = file_path_raw.resolve()
-        not_found = FileNotFound(
-            "File not found",
-            path=file_or_directory,
-            relative_url=__file_uri__,
-        )
 
         if __file_uri__:
             # Strip all / that in the beginning of the URL to help prevent
@@ -834,6 +819,29 @@ class RouteMixin(metaclass=SanicMeta):
                     f"relative_url={__file_uri__}"
                 )
                 raise not_found
+        return file_path
+
+    async def _static_request_handler(
+        self,
+        file_or_directory,
+        use_modified_since,
+        use_content_range,
+        stream_large_files,
+        request,
+        content_type=None,
+        __file_uri__=None,
+    ):
+        not_found = FileNotFound(
+            "File not found",
+            path=file_or_directory,
+            relative_url=__file_uri__,
+        )
+
+        # Merge served directory and requested file if provided
+        file_path = await self._get_file_path(
+            file_or_directory, __file_uri__, not_found
+        )
+
         try:
             headers = {}
             # Check if the client has been sent this file before
@@ -841,15 +849,13 @@ class RouteMixin(metaclass=SanicMeta):
             stats = None
             if use_modified_since:
                 stats = await stat_async(file_path)
-                modified_since = strftime(
-                    "%a, %d %b %Y %H:%M:%S GMT", gmtime(stats.st_mtime)
+                modified_since = stats.st_mtime
+                response = await validate_file(request.headers, modified_since)
+                if response:
+                    return response
+                headers["Last-Modified"] = formatdate(
+                    modified_since, usegmt=True
                 )
-                if (
-                    request.headers.getone("if-modified-since", None)
-                    == modified_since
-                ):
-                    return HTTPResponse(status=304)
-                headers["Last-Modified"] = modified_since
             _range = None
             if use_content_range:
                 _range = None
@@ -864,8 +870,7 @@ class RouteMixin(metaclass=SanicMeta):
                         pass
                     else:
                         del headers["Content-Length"]
-                        for key, value in _range.headers.items():
-                            headers[key] = value
+                        headers.update(_range.headers)
 
             if "content-type" not in headers:
                 content_type = (

tests/test_response.py

@@ -4,8 +4,8 @@ import os
 import time
 
 from collections import namedtuple
-from datetime import datetime
-from email.utils import formatdate
+from datetime import datetime, timedelta
+from email.utils import formatdate, parsedate_to_datetime
 from logging import ERROR, LogRecord
 from mimetypes import guess_type
 from pathlib import Path
@@ -665,13 +665,11 @@ def test_multiple_responses(
 
     with caplog.at_level(ERROR):
         _, response = app.test_client.get("/4")
-        print(response.json)
         assert response.status == 200
         assert "foo" not in response.text
         assert "one" in response.headers
         assert response.headers["one"] == "one"
 
-        print(response.headers)
         assert message_in_records(caplog.records, error_msg2)
 
     with caplog.at_level(ERROR):
@@ -841,10 +839,10 @@ def test_file_validate(app: Sanic, static_file_directory: str):
     time.sleep(1)
     with open(file_path, "a") as f:
         f.write("bar\n")
-
     _, response = app.test_client.get(
         "/validate", headers={"If-Modified-Since": last_modified}
     )
+
     assert response.status == 200
     assert response.body == b"foo\nbar\n"
 
@@ -921,3 +919,28 @@ def test_file_validating_304_response(
     )
     assert response.status == 304
     assert response.body == b""
+
+
+@pytest.mark.parametrize(
+    "file_name", ["test.file", "decode me.txt", "python.png"]
+)
+def test_file_validating_304_response(
+    app: Sanic, file_name: str, static_file_directory: str
+):
+    app.static("static", Path(static_file_directory) / file_name)
+
+    _, response = app.test_client.get("/static")
+    assert response.status == 200
+    assert response.body == get_file_content(static_file_directory, file_name)
+    last_modified = parsedate_to_datetime(response.headers["Last-Modified"])
+    last_modified += timedelta(seconds=1)
+    _, response = app.test_client.get(
+        "/static",
+        headers={
+            "if-modified-since": formatdate(
+                last_modified.timestamp(), usegmt=True
+            )
+        },
+    )
+    assert response.status == 304
+    assert response.body == b""