Draw.io Code Validator

Purpose

This skill defines an 8-stage validation pipeline for Draw.io mxGraph XML. Run this pipeline on EVERY diagram before presenting it to the user or saving it to a file. The pipeline catches structural, style, and geometry errors in order of severity — blocking errors first, warnings second.

Critical Rules (Memorize These)

1. ALWAYS run ALL 8 stages — NEVER skip a stage, even if earlier stages pass.
2. Stages 1-4 are BLOCKING — If ANY stage from 1 to 4 fails, STOP and fix before continuing. NEVER deliver XML that fails a blocking stage.
3. Stages 5-8 produce WARNINGS — Fix these when possible, but they do NOT block delivery.
4. ALWAYS report errors in severity order — BLOCKING errors first, then WARNINGS.
5. ALWAYS provide a fix for each error — NEVER report an error without its correction.
6. NEVER silently fix errors — Report what was found AND what was corrected.
7. ALWAYS validate the COMPLETE file — NEVER validate a partial snippet and assume the rest is correct.

Pipeline Overview