fix: capture both stdout and stderr in check execution

[YasserYG8]

Description

This PR fixes a bug in becwright's execution engine where error details written to stderr were silently discarded if the check command also output any text to stdout.

It replaces the short-circuiting logical or capture with a concatenation of both stdout and stderr outputs, ensuring developers see the complete traceback and diagnostic error logs from failing checks.

Fixes #97

Key Changes

1. Engine Capture Fix

• src/becwright/engine.py: Refactored the output retrieval in _run_check() to compile both stdout and stderr outputs into a single, newline-joined result string.

2. Testing

• tests/test_engine_integration.py: Added test_evaluate_captures_both_stdout_and_stderr which mocks a failing command printing to both channels and verifies that both outputs are correctly reported.

---

Verification Results

The test suite runs fully green:

collected 294 items
======================= 294 passed in 112.00s (0:01:52) =======================

Summary by CodeRabbit

• Bug Fixes

  • Improved rule-check output so both standard output and error messages are included when a check runs.
  • Preserved existing pass/fail behavior and timeout handling.

• Tests

  • Added coverage to verify rule checks capture both output streams in the reported result.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 1e6073e7-bd4d-42d3-ada2-f0f50d5e45c2

📥 Commits

Reviewing files that changed from the base of the PR and between d14b9b5 and e6ba396.

📒 Files selected for processing (2)

• src/becwright/engine.py
• tests/test_engine_integration.py

---

📝 Walkthrough

Walkthrough

The _run_check function in the engine module was updated to combine both stdout and stderr output from rule check subprocesses, joining them with newlines when both are present, rather than discarding stderr when stdout exists. A corresponding integration test was added.

Changes

Combined stdout/stderr output fix

Layer / File(s)	Summary
Combine stdout and stderr in check output src/becwright/engine.py, tests/test_engine_integration.py	_run_check now strips and joins both proc.stdout and proc.stderr with newlines instead of discarding stderr when stdout is non-empty; a new integration test verifies both streams appear in per_rule[0].output for a failing rule.

Estimated code review effort: 1 (Trivial) | ~3 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main fix: preserving both stdout and stderr during check execution.
Description check	✅ Passed	The description covers the bug, the fix, related issue, key changes, and test verification, though it omits the template's checklist.
Linked Issues check	✅ Passed	The code change and test directly satisfy #97 by preserving both stdout and stderr in _run_check output.
Out of Scope Changes check	✅ Passed	The PR stays focused on the output-capture fix and its test, with no apparent unrelated changes.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

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.}