Update libs, external review and refactor sync command execution

[marcomq]

Summary by CodeRabbit

• New Features

  • Enhanced async function call documentation clarifying call_function vs call_async_function usage.
  • Expanded venv setup guidance with uv-based workflow.

• Bug Fixes

  • Improved error handling for Python code with embedded NUL characters.
  • Better async call error reporting on RustPython backend.

• Chores

  • Bumped version to 0.3.1.
  • Updated dependencies (serde_json, thiserror, tokio, pyo3, rustpython).
  • Removed GitHub Actions CI workflow.

[coderabbitai]

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: eb757bf6-e784-4875-9660-d21604b3935f

📥 Commits

Reviewing files that changed from the base of the PR and between 6288b8d and 0a09d8c.

📒 Files selected for processing (2)

• README.md
• src/rustpython_runner.rs

📝 Walkthrough

Walkthrough

This PR modernizes the async_py library with a version bump to 0.3.1, dependency updates, and significant backend refactoring. The synchronous command execution mechanism is rewritten to avoid blocking Tokio runtimes. Both PyO3 and RustPython backends receive improvements: PyO3 gains centralized error handling for string-to-CString conversion, and RustPython is modernized with a builder-pattern interpreter initialization and improved error reporting. Documentation is expanded with clarifications on async function handling and venv setup.

Changes

Library modernization and backend refactoring

Layer / File(s)	Summary
Dependency version updates and metadata Cargo.toml, .gitignore	Crate version bumped to 0.3.1; dependencies updated to newer versions (serde_json, thiserror, tokio, pyo3 0.28, rustpython-vm/stdlib 0.5); once_cell removed; .gitignore updated for .serena artifact.
Backend compilation conditional gating src/lib.rs	Conditional compilation refactored to cfg(all(feature = "pyo3", not(feature = "rustpython"))); test guards updated; Tokio Handle import replaces Runtime for better modularity.
Synchronous command execution refactor src/lib.rs	Dedicated sync worker thread removed; send_command_sync now detects Tokio runtime with Handle::try_current() and offloads blocking operations to OS thread when inside async context; path canonicalization fallback prevents panic on failure.
PyO3 string-to-CString error handling src/pyo3_runner.rs	New python_code_to_cstring helper centralizes string-to-CString conversion, mapping embedded-NUL errors to Python ValueError instead of panicking; RunCode, EvalCode, and RunFile use the helper for graceful error propagation.
RustPython backend modernization src/rustpython_runner.rs	Interpreter initialization switched to builder pattern with native stdlib registration; RunFile injects parent directory into sys.path and reads file source with explicit error handling; async calls return VM-created NotImplementedError; error printing uses vm.write_exception for proper exception rendering; JSON conversions use lossy string handling.
Documentation updates and test additions README.md, src/lib.rs	README expanded with async_py version reference, call_function vs call_async_function distinction, RustPython async limitation note, set_venv clarification with uv examples, and updated inline-python comparison; new tests verify post-stop error behavior and backend-specific error reporting.
CI workflow removal src/rust.yml	GitHub Actions workflow deleted; removes the test job running cargo test on main branch across multiple platforms.

Estimated code review effort

🎯 4 (Complex) | ⏱️ ~60 minutes

Poem

🐰 A library grows up with grace,
Backends dancing in their place,
Sync no longer blocks the flow,
Errors caught where they should go,
Version bumped, let futures sing!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title mentions 'Update libs' and 'refactor sync command execution' which are significant changes in Cargo.toml and src/lib.rs, but omits major work like async handling improvements, test updates, and RustPython refactoring.

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

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch dev

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[coderabbitai]

Actionable comments posted: 1

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

src/rustpython_runner.rs (1)

218-223: ⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

Remove stale traceback line offset for main.py.

Line 219–223 still subtracts 2 from traceback lines for main.py, but RunFile now runs the user file source directly, so this remapping is no longer valid and can misreport line numbers.

Suggested fix

-            let line = if file == "main.py" {
-                original_line - 2 // sys.path import has 2 additional lines
-            } else {
-                original_line
-            };
+            let line = original_line;

🤖 Prompt for 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.

In `@src/rustpython_runner.rs` around lines 218 - 223, The code subtracts 2 from
trace.lineno for file == "main.py" (original_line - 2) which is now incorrect
since RunFile runs the user source directly; remove that special-case remapping
and always use trace.lineno.get() (i.e., set line = original_line) so reported
traceback line numbers are accurate; update the logic around original_line/line
in rustpython_runner.rs (the branch that checks file == "main.py") to stop
applying the -2 offset.

🤖 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 `@README.md`:
- Around line 104-106: The README statement about call_async_function is
misleading: instead of saying it is "only available with the default PyO3
backend", update the wording to clarify that the call_async_function API exists
for both backends but only functions at runtime with the PyO3 backend — with the
RustPython backend invoking call_async_function will return an "unsupported"
error at runtime; change the sentence around the symbol call_async_function to
explicitly mention PyO3 provides runtime support while RustPython reports
unsupported, so readers understand the API is present but behavior differs by
backend.

---

Outside diff comments:
In `@src/rustpython_runner.rs`:
- Around line 218-223: The code subtracts 2 from trace.lineno for file ==
"main.py" (original_line - 2) which is now incorrect since RunFile runs the user
source directly; remove that special-case remapping and always use
trace.lineno.get() (i.e., set line = original_line) so reported traceback line
numbers are accurate; update the logic around original_line/line in
rustpython_runner.rs (the branch that checks file == "main.py") to stop applying
the -2 offset.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

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

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: e888536d-7ca1-4e8f-93f3-6f0c3739abd2

📥 Commits

Reviewing files that changed from the base of the PR and between 469bc43 and 6288b8d.

⛔ Files ignored due to path filters (1)

• Cargo.lock is excluded by !**/*.lock

📒 Files selected for processing (7)

• .gitignore
• Cargo.toml
• README.md
• src/lib.rs
• src/pyo3_runner.rs
• src/rust.yml
• src/rustpython_runner.rs

💤 Files with no reviewable changes (1)

• src/rust.yml