fix(tests): use asyncio.run instead of get_event_loop in middleware tests

[Pouyanpi]

Python 3.13 removed auto creation of an event loop in asyncio.get_event_loop() when none is set on the thread. The pattern

asyncio.get_event_loop().run_until_complete(coro)

now raises RuntimeError("There is no current event loop in thread 'MainThread'") whenever a previous test ran asyncio.run() and closed its loop. This test-ordering race is flaky across CI runs (for ref: https://github.com/NVIDIA-NeMo/Guardrails/actions/runs/24666672357).

Replaces all nine occurrences across tests/integrations/langchain/test_middleware.py (eight) and tests/guardrails/test_iorails.py (one) with asyncio.run(...), which creates and owns its own loop. Behavior preserving python 313 compatible, independent of prior test loop state.

Test plan

tests/integrations/langchain/test_middleware.py:

92 passed in 0.74s

tests/guardrails/test_iorails.py:

28 passed in 1.42s

Summary by CodeRabbit

• Tests
  • Updated test infrastructure to use modern async event loop management patterns for improved test reliability.

---

Note: This release contains no user-facing changes. Updates are limited to internal testing infrastructure.

[greptile-apps]

Greptile Summary

Replaces nine occurrences of asyncio.get_event_loop().run_until_complete(coro) with asyncio.run(coro) across two test files to fix a Python 3.13 compatibility issue where asyncio.get_event_loop() no longer auto-creates an event loop when none is set. The fix is minimal, correct, and behavior-preserving.

Confidence Score: 5/5

Safe to merge — purely mechanical test-compatibility fix with no behavioral changes.

All nine replacements are straightforward and correct. asyncio.run() creates and owns its own loop, propagates exceptions identically to run_until_complete, and is compatible with Python 3.10–3.13. No logic, security, or data-integrity concerns.

No files require special attention.

Important Files Changed

Filename	Overview
tests/guardrails/test_iorails.py	Single replacement of asyncio.get_event_loop().run_until_complete() with asyncio.run() inside a pytest.raises(RuntimeError) block; exception propagation is identical.
tests/integrations/langchain/test_middleware.py	Eight replacements of asyncio.get_event_loop().run_until_complete() with asyncio.run() across TestSyncMethods and TestGuardrailViolationException; all are sync test methods so no nested-loop issue.

Sequence Diagram

sequenceDiagram
    participant Test as Test (sync)
    participant Old as asyncio.get_event_loop().run_until_complete()
    participant New as asyncio.run()
    participant Coro as Coroutine

    Note over Test,Old: Python ≤ 3.12 (old pattern)
    Test->>Old: get_event_loop()
    Old-->>Test: returns existing/new loop
    Test->>Old: run_until_complete(coro)
    Old->>Coro: execute
    Coro-->>Old: result / exception
    Old-->>Test: result / propagated exception

    Note over Test,New: Python 3.13+ (new pattern)
    Test->>New: asyncio.run(coro)
    New->>New: create fresh event loop
    New->>Coro: execute
    Coro-->>New: result / exception
    New->>New: close event loop
    New-->>Test: result / propagated exception

Loading

_{Reviews (1): Last reviewed commit: "fix(tests): use asyncio.run instead of g..." | Re-trigger Greptile}

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: 794d72ff-c566-4073-b679-673d9799fd6c

📥 Commits

Reviewing files that changed from the base of the PR and between 032a661 and 14cdca9.

📒 Files selected for processing (2)

• tests/guardrails/test_iorails.py
• tests/integrations/langchain/test_middleware.py

---

📝 Walkthrough

Walkthrough

This PR updates test infrastructure in two test files by replacing deprecated asyncio.get_event_loop().run_until_complete() calls with the modern asyncio.run() approach for executing asynchronous test code, affecting guardrails and langchain middleware tests.

Changes

Cohort / File(s)	Summary
Test Infrastructure Updates tests/guardrails/test_iorails.py, tests/integrations/langchain/test_middleware.py	Replaced asyncio.get_event_loop().run_until_complete(...) with asyncio.run(...) for managing async coroutine execution in synchronous test contexts. Changes affect event-loop handling without altering test assertions or production logic.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

🚥 Pre-merge checks | ✅ 3 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 9.09% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and accurately summarizes the main change: replacing asyncio.get_event_loop() calls with asyncio.run() in test files for Python 3.13 compatibility.
Test Results For Major Changes	✅ Passed	PR contains only minor test infrastructure changes (9 lines total) with no production code modifications, addressing Python 3.13 compatibility. Test results are documented showing 92 and 28 tests passing.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/tests-asyncio-run

---

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

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!