Skip to content

Fix flaky test_submissions_are_random_by_user #4527

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
marcoacierno merged 1 commit into from
Jan 10, 2026
Merged

Fix flaky test_submissions_are_random_by_user #4527

Changes from all commits
Commits
Show all changes
1 commit
Select commit
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
52 changes: 36 additions & 16 deletions backend/api/submissions/tests/test_submissions.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,20 +10,29 @@


def test_submissions_are_random_by_user(graphql_client, mock_has_ticket):
"""Test that submissions are randomized differently per user.

The randomization is seeded by user.id, so each user gets a consistent
but different ordering. We test this by:
1. Creating enough submissions to reduce collision probability
2. Verifying the same user gets the same ordering on repeated queries
3. Verifying different users get different orderings
"""
user_1 = UserFactory()
user_2 = UserFactory()
user_3 = UserFactory()

graphql_client.force_login(user_1)

# Create 10 submissions to reduce collision probability
# With 10 items, there are 10! possible orderings, making collisions extremely unlikely
submission = SubmissionFactory()
SubmissionFactory(conference=submission.conference)
SubmissionFactory(conference=submission.conference)
for _ in range(9):
SubmissionFactory(conference=submission.conference)

mock_has_ticket(submission.conference)

query = """query Submissions($code: String!, $page: Int) {
submissions(code: $code, page: $page, pageSize: 3) {
submissions(code: $code, page: $page, pageSize: 10) {
pageInfo {
totalPages
totalItems
Expand All @@ -34,21 +43,32 @@ def test_submissions_are_random_by_user(graphql_client, mock_has_ticket):
}
}"""

submissions = {}

for user in [user_1, user_2, user_3]:
graphql_client.force_login(user)
# Test that user_1 gets consistent ordering
graphql_client.force_login(user_1)
resp_1a = graphql_client.query(
query,
variables={"code": submission.conference.code, "page": 1},
)
resp_1b = graphql_client.query(
query,
variables={"code": submission.conference.code, "page": 1},
)
user_1_submissions = resp_1a["data"]["submissions"]["items"]

resp = graphql_client.query(
query,
variables={"code": submission.conference.code, "page": 1},
)
# Same user should get same ordering
assert user_1_submissions == resp_1b["data"]["submissions"]["items"]

submissions[user] = resp["data"]["submissions"]["items"]
# Test that user_2 gets a different ordering
graphql_client.force_login(user_2)
resp_2 = graphql_client.query(
query,
variables={"code": submission.conference.code, "page": 1},
)
user_2_submissions = resp_2["data"]["submissions"]["items"]

assert submissions[user_1] != submissions[user_2]
assert submissions[user_1] != submissions[user_3]
assert submissions[user_2] != submissions[user_3]
# Different users should get different orderings
# With 10 submissions, the probability of collision is 1/10! which is negligible
assert user_1_submissions != user_2_submissions


def test_returns_submissions_paginated(graphql_client, user):
Expand Down
Loading