Developer guide

For contributors working on the open_fdd package.

Local workflow

  1. Create a virtual environment and install in editable mode with dev tools:

    pip install -e ".[dev]"
pre-commit install   # optional, if you use the repo’s hooks

  2. Run the test suite:

    pytest

  3. Format with Black (version and line length are pinned in pyproject.toml).

Code layout

  • open_fdd/engine/ — RuleRunner, rule loading, checks (bounds, flatline, expression, …), ColumnMapResolver and manifest helpers.
  • open_fdd/schema/ — pydantic models for fault results and related structures.
  • open_fdd/reports/ — optional reporting helpers; may require extra packages in your environment.

Public imports are re-exported from open_fdd and open_fdd.engine where documented on Engine API.

Adding or changing rules

  • YAML rule files live alongside your application or under examples/ / open_fdd/tests/fixtures/rules/ for tests.
  • Extend engine behavior via the documented check types and expression language; see Rules overview and Expression rule cookbook.

Documentation site

The GitHub Pages site is built from docs/ with Jekyll (Just the Docs). After substantive edits, run a local bundle exec jekyll build from docs/ if you maintain the theme locally.