---
name: fesa-cpp-msvc-tdd
description: Use when planning, implementing, validating, or correcting FESA solver C++17 MSVC CMake CTest work with TDD, build/test failure triage, or implementation-plan handoffs.
---

# FESA C++ MSVC TDD

Use this skill to keep FESA C++ implementation work test-first, MSVC-compatible, and bounded by approved upstream contracts.

## Inputs

Read these first:

- `AGENTS.md`
- `docs/SOLVER_AGENT_DESIGN.md`
- `docs/implementation-plans/README.md`
- `docs/build-test-reports/README.md`
- `docs/corrections/README.md`
- `docs/implementation-plans/<feature-id>-implementation-plan.md`
- Related requirements, formulation, numerical review, I/O definition, and reference model documents

## Workflow

1. For planning, convert upstream documents into small ordered tasks and test ids.
2. For implementation, follow `RED -> GREEN -> VERIFY`.
3. RED: write the planned unit, integration, parser/I/O, or reference-comparison test first.
4. RED: run the targeted test and verify the expected failure before production code.
5. GREEN: implement the minimum C++17/MSVC-compatible code needed for the task.
6. VERIFY: run the targeted command, then `python scripts/validate_workspace.py`.
7. For C++ production changes, require a related C++ test file in the same patch or already present.
8. For failure triage, classify as `configure | compile | link | test | reference-comparison | harness | environment | upstream-contract`.
9. Fix implementation-owned failures only and keep changes traceable to the implementation plan.

## Output Contract

Produce one of these, depending on role:

- `docs/implementation-plans/<feature-id>-implementation-plan.md`
- Implementation report with RED/GREEN/VERIFY evidence
- `docs/build-test-reports/<feature-id>-build-test.md`
- `docs/corrections/<feature-id>-correction.md`

Required validation commands:

```powershell
python -m unittest discover -s scripts -p "test_*.py"
python scripts/validate_workspace.py
ctest -C Debug -R <feature-or-label>
```

Default MSVC path:

```powershell
cmake -S . -B build/msvc-debug -G "Visual Studio 17 2022" -A x64
cmake --build build/msvc-debug --config Debug
ctest --test-dir build/msvc-debug --output-on-failure -C Debug
```

## Boundaries

- Do not change requirements.
- Do not change formulations.
- Do not change I/O contracts.
- Do not change numerical review reports.
- Do not change reference artifacts.
- Do not change tolerance policies.
- Do not run Abaqus, Nastran, or any reference solver.
- Do not generate reference HDF5 files or deterministic CSV views.
- Do not approve release readiness.

## Quality Gate

- Every `must` requirement maps to at least one task and one test.
- Each test has a clear RED condition, GREEN condition, linked task, and command.
- CMake/CTest plans remain compatible with MSVC x64 Debug validation.
- Build/test reports record command, exit code, duration, stdout/stderr tail, and failure classification.
- Correction attempts stop when repeated failure indicates upstream contract ambiguity.

## Handoff

Send passing build/test evidence to Reference Verification Agent. Send implementation-owned failures to Correction Agent. Send upstream-contract failures to the owning upstream agent through Coordinator Agent.