# Codex Report - 2025-10-08T23:55:27Z

## Overview
- Compared the pristine `AA37 Department of Health.drawio` fixture against the plugin-generated `AA37 Department of Health-with-metadata.drawio` artifact to isolate the exact structural differences.
- Identified that metadata injection only affects the `<mxfile>` header, the root `<mxGraphModel>` dimensions, and replaces the root `<mxCell id="0" />` with a metadata-bearing `<UserObject>` block containing preamble entries.

## Metadata patch utility (initial pass)
- Added `tests/utils/patchDrawioWithMetadata.ts` to perform targeted textual transformations:
  - Rewrote the `<mxfile>` element with caller-supplied host/agent/version values.
  - Optionally retargeted the first `<mxGraphModel>` `dx`/`dy` dimensions without disturbing other attributes.
  - Located the root `<mxCell id="0" />` line and replaced it with an indented `<UserObject>` structure populated from declarative options (CSV path, base URI, preamble entries, optional label).
  - Guarded each mutation with explicit existence checks so fixtures remained untouched when the expected anchors were absent.

## Fixture management
- Relocated the `AA37 Department of Health-with-metadata.drawio` artifact into the test fixtures directory so it can serve as a golden regression target alongside the original drawio file.

## Regression testing (initial pass)
- Introduced a Bun test that used the new utility to patch the pristine AA37 fixture and assert byte-for-byte equivalence with the relocated metadata artifact, confirming that the surgical transformations faithfully reproduced the runtime export at the time.
- Executed `bun install` within `src/main/webapp/plugins/rdfexport` to ensure local dependencies (including `@xmldom/xmldom`) were present for the test suite.

## Test results
- `bun test src/main/webapp/plugins/rdfexport/tests/rdfexport.test.ts`

## Notes
- The metadata patch utility preserves the pristine fixture by enforcing strict structural anchors and emitting DOM-driven updates, preventing accidental drift in unrelated sections of the document.

## 2025-10-09 Follow-up
- Replaced the earlier string-based transformer with an `@xmldom/xmldom`-driven implementation that walks the DrawIO DOM, constructs the metadata `UserObject`, and re-serializes the document while preserving existing whitespace anchors for consistent fixture formatting.
- Simplified the metadata patch options so only the RDF-exported structures (preamble entries, CSV path, base URI, optional label) are touched; viewport adjustments and header rewrites are now intentionally ignored.
- Updated the regression test to compare DOM structures instead of raw strings, explicitly asserting that the patched document inherits host/agent/dx/dy attributes from the pristine fixture while matching the metadata payload found in the runtime artifact.
- Re-ran `bun test src/main/webapp/plugins/rdfexport/tests/rdfexport.test.ts` to confirm the DOM-based patch still recreates the RDF metadata layout without disturbing unrelated sections.

## 2025-10-09 Follow-up #2
- Streamlined `rdfexport.test.ts` so it now delegates entirely to `patchDrawioWithMetadata`, deriving patch inputs from the golden AA37 fixture and validating the patched output against the runtime artifact by comparing DOM snapshots of the injected metadata block.
- Removed the bespoke DrawIO UI and graph stubs that had crept into the regression test, keeping the focus on the patcher contract and eliminating duplicated logic from the production plugin.
- Verified again with `bun test src/main/webapp/plugins/rdfexport/tests/rdfexport.test.ts` that the simplified regression harness still confirms parity without mutating unrelated DrawIO attributes.

## 2025-10-09 Follow-up #3
- Restored the full `rdfexport.test.ts` suite so legacy UI and export safeguards remain under regression, keeping the new metadata patch validation additive rather than destructive.
- Added a focused fixture patch test that imports `patchDrawioWithMetadata`, patches the pristine AA37 diagram, and compares the resulting metadata DOM against the golden artifact while ensuring header and viewport attributes remain untouched.
- Re-ran `bun test src/main/webapp/plugins/rdfexport/tests/rdfexport.test.ts` to confirm all historical coverage passes alongside the new regression.