whetstone_DSL/sprint49_plan.md

Sprint 49 Plan: Executable Equivalence Harness

Context

Current equivalence signals are heuristic-heavy. Sprint 49 introduces executable, repeatable differential verification between source and transpiled targets.

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Goals

1. Execute source and target against identical test vectors
2. Add property-based and fuzz-based differential checks
3. Persist equivalence evidence for migration reports
4. Replace heuristic-only confidence with measured confidence

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Steps

Step 719: Differential execution harness core (12 tests)

Step 720: Deterministic test vector specification format (10 tests)

Step 721: Rust runner adapter for harness (10 tests)

Step 722: C++ runner adapter for harness (10 tests)

Step 723: Property-based equivalence runner (10 tests)

Step 724: Fuzz differential runner with seed replay (10 tests)

Step 725: Behavioral divergence packet + minimization (8 tests)

Step 726: whetstone_verify_executable_equivalence MCP tool (8 tests)

Step 727: Equivalence evidence bundle exporter (8 tests)

Step 728: Sprint 49 integration summary + regression (8 tests)

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Equivalence Rules

• Same output shape and semantic value for approved domains
• Error behavior classified as equivalent/acceptable divergence/unacceptable divergence
• Confidence scores derive from measured pass rates, not syntax patterns