Skip to content

fix(middleware): always honor js_wait after selenium page load #103

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
tharropoulos merged 2 commits into from
May 27, 2026
Merged

fix(middleware): always honor js_wait after selenium page load #103

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
9012de5
test(middlware): add coverage for js wait behavior in downloader midd…
tharropoulos May 27, 2026
e09489f
fix: honor js wait after selenium page load timeout
tharropoulos May 27, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 6 additions & 2 deletions scraper/src/custom_downloader_middleware.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -27,15 +27,19 @@ def process_request(self, request, spider):

print("Getting " + request.url + " from selenium")

self.driver.get(unquote_plus(
request.url)) # Decode url otherwise firefox is not happy. Ex /#%21/ => /#!/%21
self.driver.get(
unquote_plus(request.url)
) # Decode url otherwise firefox is not happy. Ex /#%21/ => /#!/%21

try:
# Wait for DOM ready
WebDriverWait(self.driver, 10).until(
lambda d: d.execute_script("return document.readyState") == "complete"
)
except TimeoutException:
pass

if spider.js_wait:
time.sleep(spider.js_wait)

body = self.driver.page_source.encode("utf-8")
Expand Down
67 changes: 67 additions & 0 deletions scraper/src/tests/custom_downloader_middleware_test.py
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,67 @@
from types import SimpleNamespace
from unittest.mock import MagicMock, patch

from selenium.common.exceptions import TimeoutException

from ..custom_downloader_middleware import CustomDownloaderMiddleware


def _make_driver(ready_states):
"""Driver whose document.readyState returns the next value on each call."""
states = iter(ready_states)
driver = MagicMock()
driver.execute_script.side_effect = lambda *_: next(states)
driver.page_source = "<html></html>"
driver.current_url = "https://example.com/"
return driver


def _make_request(url="https://example.com/"):
return SimpleNamespace(url=url, replace=_make_request)


def test_js_wait_is_honored_when_ready_state_completes_quickly():
"""js_wait must apply even when readyState=complete."""
CustomDownloaderMiddleware.driver = _make_driver(["complete"])
middleware = CustomDownloaderMiddleware()
spider = SimpleNamespace(js_render=True, js_wait=3, remove_get_params=False)

with patch("scraper.src.custom_downloader_middleware.time.sleep") as sleep:
middleware.process_request(_make_request(), spider)

sleep.assert_called_once_with(3)


def test_js_wait_is_honored_on_ready_state_timeout():
CustomDownloaderMiddleware.driver = _make_driver(["loading"])
middleware = CustomDownloaderMiddleware()
spider = SimpleNamespace(js_render=True, js_wait=2, remove_get_params=False)

with (
patch("scraper.src.custom_downloader_middleware.time.sleep") as sleep,
patch("scraper.src.custom_downloader_middleware.WebDriverWait") as wait,
):
wait.return_value.until.side_effect = TimeoutException()
middleware.process_request(_make_request(), spider)

sleep.assert_called_once_with(2)


def test_zero_js_wait_skips_sleep():
CustomDownloaderMiddleware.driver = _make_driver(["complete"])
middleware = CustomDownloaderMiddleware()
spider = SimpleNamespace(js_render=True, js_wait=0, remove_get_params=False)

with patch("scraper.src.custom_downloader_middleware.time.sleep") as sleep:
middleware.process_request(_make_request(), spider)

sleep.assert_not_called()


def test_js_render_disabled_short_circuits():
CustomDownloaderMiddleware.driver = MagicMock()
middleware = CustomDownloaderMiddleware()
spider = SimpleNamespace(js_render=False, js_wait=5, remove_get_params=False)

assert middleware.process_request(_make_request(), spider) is None
middleware.driver.get.assert_not_called()
Loading