gtm-demo-validation-cache-regression-repair

name	gtm-demo-validation-cache-regression-repair
description	Diagnose and repair GTM demo validation failures caused by legacy cache files missing intermediate chart data, especially in nested digitalmodel demo scripts using --from-cache.
version	1.0.0
category	workspace-hub-learned
tags	["gtm","digitalmodel","validation","cache","regression","pytest"]

GTM demo validation cache regression repair

Use when digitalmodel/examples/demos/gtm/tests/test_gtm_demos.py fails on a --from-cache smoke test after a demo script was retrofitted to cache more intermediate chart data.

Trigger pattern

Typical symptom:

• PYTHONPATH=examples/demos/gtm:src uv run pytest examples/demos/gtm/tests/test_gtm_demos.py -q
• one failing demo, often Demo 2 wall thickness
• error from cached path like NameError: PipeDefinition is not defined

Root cause pattern:

• the script's cached mode assumes newly added intermediate keys exist in old committed JSON
• legacy cache only contains core keys like metadata/results/summary
• chart builders fall through into engineering-calculation code paths, which require symbols that cached mode never initialized

Proven workflow

1. Reproduce in the nested repo, not only the outer workspace-hub repo.

   • cd /mnt/local-analysis/workspace-hub/digitalmodel
   • PYTHONPATH=examples/demos/gtm:src uv run pytest examples/demos/gtm/tests/test_gtm_demos.py -q

2. Inspect the failing script and the committed cache JSON together.

   • confirm which intermediate keys the script now expects
   • inspect the current results JSON to see whether those keys actually exist

3. Prefer a compatibility fix over forcing cache deletion.

   • add a helper like _cache_has_intermediate_data(cached)
   • if --from-cache loads a legacy JSON without required intermediate keys, log a clear message and fall back to full recalculation
   • also initialize any constants/imports still needed by downstream chart builders even in cache/regeneration mode

4. Re-run both:

   • full GTM test suite
   • targeted failing subset, e.g. -k wall_thickness

5. Clean generated artifact churn before committing.

   • GTM tests can rewrite tracked HTML/JSON outputs
   • revert unrelated regenerated files with git checkout -- ...
   • commit only the code fix unless output regeneration is intentionally part of the change

Minimal repair pattern

In the script:

• define required cache keys
• detect whether loaded JSON has them
• if not, switch from cache mode to full-calc mode
• initialize code-name constants/imported enums for both cache and full modes when chart builders depend on them

Verification standard

Required:

• PYTHONPATH=examples/demos/gtm:src uv run pytest examples/demos/gtm/tests/test_gtm_demos.py -q passes
• targeted regression subset passes
• nested repo git status is clean except for intended code changes before commit

Important notes

• digitalmodel is a nested git repo under workspace-hub; status/history/commits must be checked there.
• A green GTM pytest suite clears the test-suite blocker for workspace-hub issue tracking, but does not by itself satisfy higher-level GTM approval gates like browser validation or hand checks.