# RDF Export Plugin – Bugfix Report (Flowchart Tweaked metadata regression)

## Summary
- Investigated pytest failure triggered by `test_generated_metadata_fixtures_round_trip` where Flowchart fixtures caused `ArrowWithoutIndividualAsSourceException`.
- Determined root cause: legacy DrawIO fixtures still using `<object>` metadata envelope were ignored by `_extract_drawio_metadata`, so the `kb` prefix never reached the classifier, leaving decision nodes treated as literals. Metadata patcher also overwrote legacy prefixes when injecting modern metadata.
- Added a new override (`legacy/overrides/metadata_extraction.py`) so `_extract_drawio_metadata` recognises both `<UserObject>` and legacy `<object>` wrappers and harvests existing preamble entries.
- Updated `tests/utils/patchDrawioWithMetadata.ts` to merge any pre-existing preamble entries into the generated metadata, preserving legacy prefixes when the fixture already declared them.
- Regenerated the parser via `python -m meta_builder -o legacy/draw_io_parser.py` and reformatted with Ruff & Prettier.

## Commands Executed
- Environment prep: `bun install`, `bun run setup:uv`, `bun run setup:pyodide`, `bun run test`, `bun run check` (with supporting lint/format subtasks), plus targeted `pytest legacy/tests/test_patched_parser.py::test_generated_metadata_fixtures_round_trip` during diagnosis.
- Formatting: `ruff format`, `prettier --write .` (with CI log-level guard) to satisfy repository style gates.

## Testing
- Targeted pytest run for `legacy/tests/test_patched_parser.py::test_generated_metadata_fixtures_round_trip` confirmed the regression fix locally before rerunning the full suite.
- `bun run test` (legacy + TypeScript + Pyodide integration) and `bun run check` executed cleanly with all existing skips unchanged.

## Notes
- No CHANGELOG entry provided for this focused bugfix per existing project cadence.
- Flowchart fixtures continue to be skipped in baseline regeneration until dedicated `.nt` fixtures exist; behaviour unchanged by this patch.