fix: apply score_threshold filtering after fusion queries in local mode

[cbcoutinho]

Summary

• Fixed score_threshold not being applied after RRF and DBSF fusion operations in local/memory mode
• Added local-only tests to verify fusion score_threshold filtering works correctly
• Added congruence tests for RRF and DBSF with score_threshold

Test plan

• test_fusion_rrf_score_threshold - verifies RRF fusion respects score_threshold
• test_fusion_dbsf_score_threshold - verifies DBSF fusion respects score_threshold
• Tests fail without the fix, pass with the fix
• Run congruence tests against remote Qdrant server

Fixes:

• [Local Mode] score_threshold not applied to FusionQuery results #1136

---

This PR was generated with the help of AI, and reviewed by a Human

[netlify]

✅ Deploy Preview for poetic-froyo-8baba7 ready!

Name	Link
🔨 Latest commit	69eadfb
🔍 Latest deploy log	https://app.netlify.com/projects/poetic-froyo-8baba7/deploys/694118545e492800088dada0
😎 Deploy Preview	https://deploy-preview-1137--poetic-froyo-8baba7.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[coderabbitai]

📝 Walkthrough

Walkthrough

Adds post-fusion score threshold filtering in qdrant_client/local/local_collection.py: after fusion (RRF/DBSF) produces fused scored points, if score_threshold is provided the code filters out points with score < score_threshold before retrieving payloads/vectors and applying offset/limit. No public signatures changed. Tests were added/updated to cover RRF and DBSF fusion behavior with thresholds.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

• Changes are localized: one functional edit in local_collection.py plus new tests.
• Review focus: correctness of the threshold comparison, interaction with subsequent payload/vector fetch and offset/limit handling, and that tests exercise both fusion methods.
• Files to pay attention to:
  • qdrant_client/local/local_collection.py
  • tests/test_in_memory.py
  • tests/congruence_tests/test_query.py

Possibly related issues

• [Local Mode] score_threshold not applied to FusionQuery results #1136 — The issue requests post-fusion score_threshold filtering; this PR implements that behavior.

Possibly related PRs

• new: queryless score 1 #1088 — Modifies scoring behavior in the same local_collection scoring/fusion area; conceptually related to how fused scores are produced and subsequently filtered.

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically describes the main change: applying score_threshold filtering after fusion queries in local mode.
Description check	✅ Passed	The description is directly related to the changeset, detailing the fix for score_threshold filtering in fusion operations, the tests added, and the issue addressed.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

---

📜 Recent review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between a62ec30 and 69eadfb.

📒 Files selected for processing (1)

• tests/congruence_tests/test_query.py (2 hunks)

🚧 Files skipped from review as they are similar to previous changes (1)

• tests/congruence_tests/test_query.py

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (3)

• GitHub Check: Redirect rules - poetic-froyo-8baba7
• GitHub Check: Header rules - poetic-froyo-8baba7
• GitHub Check: Pages changed - poetic-froyo-8baba7

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[joein]

Hey @cbcoutinho

Thanks for pointing this out and contributing a fix!
I've adjusted PR a bit to simplify some of the tests.

P.S. Base branch for new pull requests should be dev, not master. I think it'll be easier to recreate the PR from the proper branch. Would you like to do that or should I?

[cbcoutinho]

Hi @joein, thanks for the review - closing in favor of #1138 which targets the dev branch instead of main