url_file: fix non-200 files being cached (#30886)

* fix + test

* fix unclosed

* easier to read

Co-authored-by: Shane Smiskol <shane@smiskol.com>

* fix that

---------

Co-authored-by: Shane Smiskol <shane@smiskol.com>

tools/lib/tests/test_caching.py

@@ -1,15 +1,58 @@
 #!/usr/bin/env python3
+from functools import wraps
+import http.server
 import os
+import threading
+import time
 import unittest
 
-from pathlib import Path
 from parameterized import parameterized
-from unittest import mock
 
-from openpilot.system.hardware.hw import Paths
 from openpilot.tools.lib.url_file import URLFile
 
 
+class CachingTestRequestHandler(http.server.BaseHTTPRequestHandler):
+  FILE_EXISTS = True
+
+  def do_GET(self):
+    if self.FILE_EXISTS:
+      self.send_response(200, b'1234')
+    else:
+      self.send_response(404)
+    self.end_headers()
+
+  def do_HEAD(self):
+    if self.FILE_EXISTS:
+      self.send_response(200)
+      self.send_header("Content-Length", "4")
+    else:
+      self.send_response(404)
+    self.end_headers()
+
+
+class CachingTestServer(threading.Thread):
+  def run(self):
+    self.server = http.server.HTTPServer(("127.0.0.1", 0), CachingTestRequestHandler)
+    self.port = self.server.server_port
+    self.server.serve_forever()
+
+  def stop(self):
+    self.server.server_close()
+    self.server.shutdown()
+
+def with_caching_server(func):
+  @wraps(func)
+  def wrapper(*args, **kwargs):
+    server = CachingTestServer()
+    server.start()
+    time.sleep(0.25) # wait for server to get it's port
+    try:
+      func(*args, **kwargs, port=server.port)
+    finally:
+      server.stop()
+  return wrapper
+
+
 class TestFileDownload(unittest.TestCase):
 
   def compare_loads(self, url, start=0, length=None):
@@ -66,32 +109,20 @@ class TestFileDownload(unittest.TestCase):
     self.compare_loads(large_file_url)
 
   @parameterized.expand([(True, ), (False, )])
-  def test_recover_from_missing_file(self, cache_enabled):
+  @with_caching_server
+  def test_recover_from_missing_file(self, cache_enabled, port):
     os.environ["FILEREADER_CACHE"] = "1" if cache_enabled else "0"
 
-    file_url = "http://localhost:5001/test.png"
-
-    file_exists = False
+    file_url = f"http://localhost:{port}/test.png"
 
-    def get_length_online_mock(self):
-      if file_exists:
-        return 4
-      return -1
-
-    patch_length = mock.patch.object(URLFile, "get_length_online", get_length_online_mock)
-    patch_length.start()
-    try:
+    CachingTestRequestHandler.FILE_EXISTS = False
     length = URLFile(file_url).get_length()
     self.assertEqual(length, -1)
 
-      file_exists = True
+    CachingTestRequestHandler.FILE_EXISTS = True
     length = URLFile(file_url).get_length()
     self.assertEqual(length, 4)
-    finally:
-      tempfile_length = Path(Paths.download_cache_root()) / "ba2119904385654cb0105a2da174875f8e7648db175f202ecae6d6428b0e838f_length"
-      if tempfile_length.exists():
-        tempfile_length.unlink()
-      patch_length.stop()
+
 
 
 if __name__ == "__main__":

tools/lib/url_file.py

@@ -57,6 +57,8 @@ class URLFile:
   def get_length_online(self):
     timeout = Timeout(connect=50.0, read=500.0)
     response = self._http_client.request('HEAD', self._url, timeout=timeout, preload_content=False)
+    if not (200 <= response.status <= 299):
+      return -1
     length = response.headers.get('content-length', 0)
     return int(length)