fix(library): missing "global $relevant_chunks" declaration in hf_classifier retrieval flows

[ekam-walia]

Description

Added global $relevant_chunks before the reassignment in both flow files:

1. nemoguardrails/library/hf_classifier/flows.co
2. nemoguardrails/library/hf_classifier/flows.v1.co

Related Issue(s)

Every PR must link to a triaged issue assigned to the PR author.

• Fixes bug: missing "global $relevant_chunks" declaration in hf_classifier retrieval flows #2172
• Issue assignee: @Pouyanpi

Verification

AI Assistance

• [ x] No AI tools were used.

Checklist

• [ x] I've read the CONTRIBUTING guidelines.
• [ x] This PR links to a triaged issue assigned to me.
• [ x] My PR title follows the project commit convention.
• I've updated the documentation if applicable.
• [ x] I've added tests if applicable.
• [ x] I've noted any verification beyond CI and any checks I couldn't run.
• I did not update generated changelog files manually.
• [ x] I addressed all CodeRabbit, Greptile, and other review comments, or replied with why no change is needed.
• @mentions of the person or team responsible for reviewing proposed changes.

Summary by CodeRabbit

• Bug Fixes

  • Fixed retrieval classification so relevant content is correctly preserved and available to calling flows.
  • Ensured existing content remains unchanged when no transformation occurs or processing is blocked.
  • Improved consistency across classifier flow versions and repeated classifier calls.

• Tests

  • Added comprehensive coverage for retrieval propagation, blocked responses, empty results, and classifier configurations.

[github-actions]

PR merge guidance

@ekam-walia thanks for the PR. GitHub is currently blocking merge for one or more repository requirements:

• 4 commits do not have a verified signature (0b49f39, c10d0b5, bf12276, c552210). Please sign the commits and force-push the updated branch.

Relevant guide:

• Signed commits: https://github.com/NVIDIA-NeMo/Guardrails/blob/develop/CONTRIBUTING.md#commit-signing
• Contribution guide: https://github.com/NVIDIA-NeMo/Guardrails/blob/develop/CONTRIBUTING.md

[ekam-walia]

cc @Pouyanpi

[ekam-walia]

@Pouyanpi can you please review, if the code is making sense

[ekam-walia]

@Pouyanpi any updates on this PR

[Pouyanpi]

@ekam-walia I've reviewed your PR but you've not addressed my review comments. Please take a look

[greptile-apps]

Greptile Summary

Fixes retrieval-chunk propagation across both Colang dialects.

• Declares $relevant_chunks global before transformed assignment in the Colang 2.x flow.
• Uses Colang 1.0 shared-context assignment without the unsupported global statement or a discarded subflow return value.
• Adds regression coverage for transformed, unchanged, empty, and blocked retrieval results.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains; the Colang 1.0 flow now relies on its shared context without unsupported syntax or a discarded return value, while the Colang 2.x flow explicitly updates the global retrieval context.

Important Files Changed

Filename	Overview
nemoguardrails/library/hf_classifier/flows.co	Adds the valid Colang 2.x global declaration so transformed retrieval chunks propagate to the calling context.
nemoguardrails/library/hf_classifier/flows.v1.co	Preserves direct shared-context assignment while removing the unsupported global statement and avoiding reliance on a subflow return value.
tests/test_hf_classifier_retrieval_global.py	Adds regression scenarios covering transformed chunks, unchanged chunks, empty transformations, and blocked retrieval checks.

_{Reviews (3): Last reviewed commit: "." | Re-trigger Greptile}

[coderabbitai]

📝 Walkthrough

Walkthrough

The HF classifier retrieval flows now propagate transformed relevant_chunks through the shared context. New tests cover v1 and original flows, caller visibility, blocked responses, empty transforms, repeated calls, and explicit classifier parameters.

Changes

HF classifier retrieval propagation

Layer / File(s)	Summary
Update retrieval flow scope nemoguardrails/library/hf_classifier/flows.co, nemoguardrails/library/hf_classifier/flows.v1.co	Both retrieval flows declare relevant_chunks as global before assigning transformed values.
Validate propagation behavior tests/test_hf_classifier_retrieval_global.py	Adds mocked classifier tests covering transformed, empty, blocked, repeated, caller-flow, original-flow, and explicit-classifier scenarios.

Estimated code review effort: 2 (Simple) | ~10 minutes

🚥 Pre-merge checks | ✅ 6

✅ Passed checks (6 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the main fix: adding the missing global declaration in both hf_classifier retrieval flows.
Linked Issues check	✅ Passed	The PR updates both retrieval flows and adds tests showing transformed relevant_chunks propagates as required by #2172.
Out of Scope Changes check	✅ Passed	The changes stay focused on the reported bug fix and the matching test coverage.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Test Results For Major Changes	✅ Passed	PASS: This is a minor two-line scope fix in the flow files, so the empty Verification section is acceptable under the check.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

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[coderabbitai]

Actionable comments posted: 4

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@tests/test_hf_classifier_retrieval_global.py`:
- Around line 1-13: Remove the manually added copyright and Apache license
header from tests/test_hf_classifier_retrieval_global.py, leaving pre-commit to
insert the repository-standard header automatically.
- Line 36: Remove the newly added explanatory # comments throughout the test
cases in tests/test_hf_classifier_retrieval_global.py, including the listed
ranges, while preserving all test code and behavior unchanged.
- Around line 202-240: Update
test_hf_classifier_v1_retrieval_blocked_with_exceptions to exercise the
retrieval flow and changed retrieval scope rather than registering and executing
hf_classifier_check_input. Either move the test into the input-flow test area if
it is intended to cover input behavior, or register and invoke the retrieval
action/flow while preserving the assertion that blocked processing leaves
relevant_chunks unchanged.
- Around line 163-200: Update
test_hf_classifier_v1_retrieval_with_empty_transform_text so
MockHfClassifierResponse.transform_text includes an empty relevant_chunks value,
matching the v1 flow’s transform_text["relevant_chunks"] lookup. Assert both the
original_chunks context and relevant_chunks context, verifying the original
remains unchanged while the transformed value is propagated.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

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Run ID: baf1210b-6c7a-4c74-848f-478752181795

📥 Commits

Reviewing files that changed from the base of the PR and between b237e39 and c10d0b5.

📒 Files selected for processing (3)

• nemoguardrails/library/hf_classifier/flows.co
• nemoguardrails/library/hf_classifier/flows.v1.co
• tests/test_hf_classifier_retrieval_global.py

[ekam-walia]

@Pouyanpi ptal made the reqd changes