Files
siftlode/backend/tests/test_facebook_impersonation.py
T
peter 90ee34a1b4 feat(downloads): a Facebook group post downloads its own video, or says it has none
Given a group post's link, yt-dlp either found no formats or took another
video from the page's feed data, so a "successful" retry of such a post was a
wrong download. With the user's cookie the Facebook adapter now reads the post
page, takes the single video node in the script blocks that carry the post id,
and downloads that video's watch link (the Chrome retry does the rest). No
single video in the post fails with its own message and the group-post copy,
reworded to say the post has no video; the post link is never handed to yt-dlp
as a fallback. Without a cookie nothing changes.
2026-09-13 23:38:11 +02:00

206 lines
8.1 KiB
Python

"""E11.5 S3 + S4 — the Facebook download path with the user's cookie.
S3, measured on dev (yt-dlp 2026.07.04, the owner's cookie): reel 806379462330494 fails with the cookie
alone and extracts 2560p with `--impersonate chrome`; the reels that already download with the cookie
keep their plain first attempt. These pin the attempt order through the real download loop
(`pipeline._extract_with_fallback`, with yt-dlp faked at the `YoutubeDL` boundary), and that the
LOCKED curl_cffi can actually impersonate — the pair only works inside yt-dlp's own version range, and
outside it every target silently reports "unavailable".
S4, measured on dev and in the owner's Chrome: given a group post's link, yt-dlp finds no formats or
downloads another video from the page's feed. The post's own video is the single Video node in the
page scripts that carry the post id (prod posts 66, 145, 140, 143, 221; text posts have none while the
page holds ~10 other videos), and its watch link downloads.
"""
import pytest
import yt_dlp
from yt_dlp.networking.impersonate import ImpersonateTarget
from app.downloads import adapters, pipeline
from app.downloads import errors as dlerrors
_URL = "https://www.facebook.com/reel/806379462330494/?fs=e&fs=e"
_POST = "1755988225525547"
_GROUP_LINK = f"https://www.facebook.com/groups/983554479435596/permalink/{_POST}/?"
_POST_VIDEO = "1408015447857753"
_FEED_VIDEO = "1056963063816966" # what yt-dlp downloaded from this post's link: a feed video
_CHROME = ImpersonateTarget.from_str("chrome")
def _video_node(video_id: str) -> str:
# The measured shape of a post's attachment in the page JSON.
return '{"media":{"__typename":"Video","id":"%s","__isNode":"Video"},"styles":{}}' % video_id
def _page(*post_videos: str, post: str = _POST) -> str:
attachments = ",".join(_video_node(v) for v in post_videos)
return (
'<html><script type="application/json" data-sjs>'
f'{{"post_id":"{post}","creation_time":1785084554,"attachments":[{attachments}]}}</script>'
'<script type="application/json" data-sjs>'
f'{{"feed":[{_video_node(_FEED_VIDEO)}]}}</script></html>'
)
_WALL = (
"ERROR: [facebook] 806379462330494: Cannot parse data; please report this issue on "
"https://github.com/yt-dlp/yt-dlp/issues?q= , filling out the appropriate issue template."
)
_NO_FORMATS = "ERROR: [facebook] 2541212983053999: No video formats found!"
def test_the_locked_curl_cffi_can_impersonate_chrome():
# YoutubeDL refuses to start when the target is unavailable — the same check a download makes.
with yt_dlp.YoutubeDL({"impersonate": ImpersonateTarget.from_str("chrome"), "quiet": True}):
pass
@pytest.fixture
def ydl(monkeypatch):
"""Fake `yt_dlp.YoutubeDL`: records each attempt's options and plays back `outcomes` in order;
`web["page"]` is what a page read returns, and `web` records the pages opened and links extracted."""
seen: list[dict] = []
outcomes: list = []
web: dict = {"page": "", "opened": [], "extracted": []}
class FakeYDL:
def __init__(self, opts):
seen.append(opts)
def __enter__(self):
return self
def __exit__(self, *exc):
return False
def urlopen(self, url):
web["opened"].append(url)
body = web["page"].encode()
class Response:
def read(self, amt=None):
return body
return Response()
def extract_info(self, url, download):
web["extracted"].append(url)
outcome = outcomes.pop(0)
if isinstance(outcome, str):
raise yt_dlp.utils.DownloadError(outcome)
return outcome
monkeypatch.setattr(pipeline.yt_dlp, "YoutubeDL", FakeYDL)
monkeypatch.setattr(pipeline, "_touch_job", lambda job_id: None)
monkeypatch.setattr(pipeline, "_set_job", lambda job_id, **fields: None)
return seen, outcomes, web
def _run(tmp_path, cookiefile, url=_URL):
return pipeline._extract_with_fallback(
1, 1, url, {}, tmp_path, adapters.FacebookAdapter(), cookiefile=cookiefile
)
def test_a_cookie_download_at_the_wall_is_retried_as_chrome(ydl, tmp_path):
seen, outcomes, web = ydl
outcomes += [_WALL, {"id": "806379462330494"}]
assert _run(tmp_path, "/cookies.txt") == {"id": "806379462330494"}
assert [o.get("impersonate") for o in seen] == [None, _CHROME]
assert all(o["cookiefile"] == "/cookies.txt" for o in seen) # the retry stays signed in
assert web["opened"] == [] # a reel is not a group post: no page read
def test_without_a_cookie_the_wall_is_the_login_wall_and_final(ydl, tmp_path):
seen, outcomes, _ = ydl
outcomes += [_WALL]
with pytest.raises(yt_dlp.utils.DownloadError):
_run(tmp_path, None)
assert len(seen) == 1 and "impersonate" not in seen[0]
def test_other_facebook_failures_are_not_retried_as_chrome(ydl, tmp_path):
seen, outcomes, _ = ydl
outcomes += [_NO_FORMATS]
with pytest.raises(yt_dlp.utils.DownloadError):
_run(tmp_path, "/cookies.txt")
assert len(seen) == 1 and "impersonate" not in seen[0]
# --- S4: a group post downloads ITS video, or fails saying it has none ----------------------------
def test_a_cookie_group_post_downloads_the_posts_own_video(ydl, tmp_path):
seen, outcomes, web = ydl
web["page"] = _page(_POST_VIDEO)
outcomes += [_WALL, {"id": _POST_VIDEO}] # the watch link needs Chrome too (measured)
assert _run(tmp_path, "/cookies.txt", _GROUP_LINK) == {"id": _POST_VIDEO}
assert web["opened"] == [_GROUP_LINK]
assert seen[0]["cookiefile"] == "/cookies.txt" # the post page is read signed in
watch = f"https://www.facebook.com/watch/?v={_POST_VIDEO}"
# Never the post link: that is where the feed video comes from.
assert web["extracted"] == [watch, watch]
assert [o.get("impersonate") for o in seen[1:]] == [None, _CHROME]
def test_a_group_post_without_a_single_video_fails_saying_so(ydl, tmp_path):
_, _, web = ydl
web["page"] = _page() # a text post: the only video on the page is the feed's
with pytest.raises(RuntimeError) as exc:
_run(tmp_path, "/cookies.txt", _GROUP_LINK)
assert web["extracted"] == [] # yt-dlp is not left to guess from the post link
assert dlerrors.diagnose(str(exc.value), url=_GROUP_LINK, cookie_attached=True) == (
"format_unavailable",
"facebook.group_post_video",
)
def test_without_a_cookie_the_group_post_link_goes_to_ytdlp_unchanged(ydl, tmp_path):
_, outcomes, web = ydl
outcomes += [_NO_FORMATS]
with pytest.raises(yt_dlp.utils.DownloadError):
_run(tmp_path, None, _GROUP_LINK)
assert web["opened"] == [] # signed out the page is the login wall: nothing to read
assert web["extracted"] == [_GROUP_LINK]
def test_the_group_post_link_forms_are_recognised():
for url in (
_GROUP_LINK,
f"https://www.facebook.com/groups/983554479435596/posts/{_POST}/",
f"https://m.facebook.com/groups/983554479435596/permalink/{_POST}/?",
f"https://www.facebook.com/groups/chatgptmagyarul/posts/{_POST}",
):
assert adapters.facebook_group_post_id(url) == _POST, url
for url in (
_URL,
f"https://www.facebook.com/watch/?v={_POST_VIDEO}",
f"https://facebook.com.evil/groups/x/permalink/{_POST}/",
"https://www.facebook.com/groups/983554479435596/",
):
assert adapters.facebook_group_post_id(url) is None, url
assert adapters.SourceAdapter().resolve_url(_GROUP_LINK, {"cookiefile": "/c"}) == _GROUP_LINK
def test_only_the_single_video_of_the_posts_own_blocks_counts():
assert adapters.facebook_post_video_id(_page(_POST_VIDEO), _POST) == _POST_VIDEO
# No video in the post, although the page has one elsewhere.
assert adapters.facebook_post_video_id(_page(), _POST) is None
# Two videos: guessing between them would be the wrong-video bug again.
assert adapters.facebook_post_video_id(_page(_POST_VIDEO, "2063302677911049"), _POST) is None
# A longer number that merely STARTS with the post id is another object.
assert adapters.facebook_post_video_id(_page(_POST_VIDEO, post=_POST + "0"), _POST) is None