Summary

Explore adding fixture support to rtest's native runner, including conftest.py discovery. This would allow users to define reusable test setup/teardown logic.

Background

rtest currently supports class-level setup_method()/teardown_method() but lacks pytest-style fixtures. After researching how pytest-xdist handles fixtures with parallel workers, we've identified several feasible approaches.

Worker Isolation

Like pytest-xdist, rtest workers are isolated processes. This means:

• Each worker can independently load conftest.py files
• Fixture resolution happens at runtime in Python, not Rust
• "Session scope" means per-worker-session (same as xdist)

Design Options

Python-Only Implementation

Add fixture support entirely in the Python worker layer:

• Workers walk directory tree to discover conftest.py files
• Extract @pytest.fixture decorated functions at runtime
• Resolve fixture dependencies via function signature inspection
• Inject resolved fixtures into test functions

Rust Collection + Python Execution

Rust parses conftest.py files during collection to extract fixture metadata (names, scopes, dependencies), then passes this to workers.

Native rtest Fixtures

Define a new @rtest.fixture decorator with simpler semantics than pytest:

• Explicit scope declaration
• No request object
• No indirect parametrization

Related

• pytest-xdist has the same session-scope limitation: Session-Scoped Fixtures are not Session-Scoped with Pytest-Xdist pytest-dev/pytest-xdist#271
• Current setup/teardown support: setup_method(), teardown_method(), setUp(), tearDown()