FESADev/phases/1-linear-static-mitc4/step5.md

Step 5: domain-validation-diagnostics

Sprint Contract

Objective

Implement Domain validation and singular-prone pre-solve diagnostics required before DOF and solver work.

Required Reading

• /AGENTS.md
• /PROGRESS.md
• /PLAN.md
• /docs/README.md
• /docs/HARNESS_ENGINEERING.md
• /docs/ARCHITECTURE.md
• /docs/ADR.md
• /docs/NUMERICAL_CONVENTIONS.md
• /docs/ABAQUS_INPUT_SUBSET.md
• /docs/VERIFICATION_PLAN.md
• /phases/1-linear-static-mitc4/step4.md

Scope

• Validate node, element, set, material, property, load, boundary, and step references.
• Add singular-prone diagnostics for no active elements, no material/property, no boundary constraints, untouched free DOFs when detectable, and invalid active step data.
• Keep diagnostics actionable and source-linked where parser information is available.

Allowed Files

• include/**
• src/**
• tests/**
• docs/VERIFICATION_PLAN.md only for clarification of diagnostic test expectations
• PLAN.md
• PROGRESS.md
• phases/1-linear-static-mitc4/index.json

Explicit Non-Goals

• Do not implement DofManager, assembly, or solver singularity handling in this step.
• Do not add mesh quality diagnostics; Phase 1 excludes them.
• Do not accept unsupported parser features to make validation easier.

Tests To Write First

• Validation tests for missing nodes, missing sets, missing materials, missing shell sections, invalid element connectivity, invalid loads, and invalid boundary references.
• Singular-prone tests for no active elements, unconstrained models, and untouched free DOF candidates where detectable without assembly.
• Diagnostic payload tests for code, severity, message, and source/model context.

Reference Artifacts

• None.

Acceptance Commands

python scripts/validate_workspace.py

Evaluator Checklist

• Diagnostics align with docs/NUMERICAL_CONVENTIONS.md and docs/VERIFICATION_PLAN.md.
• Validation is separate from parsing and analysis execution.
• Mesh quality checks were not introduced.
• Tests cover failure modes, not only valid models.

Handoff Requirements

• Record validation coverage and command results in PROGRESS.md.
• Update PLAN.md if singular diagnostics require later solver support.
• Update the matching phase index entry: use completed with a one-line summary, or blocked with blocked_reason, or error with error_message.

Verification

1. Run the acceptance command.
2. Review negative tests for clear diagnostics and no mesh-quality drift.

Do Not

• Do not defer singular diagnostics entirely to the linear solver.