prometeu-runtime/docs/specs/pbs/files/PRs para Junie.md

PR-12 — VM test harness: stepper, trace, and property tests

Why: Industrial quality means test tooling, not just “it runs”.

Scope

• Add VmRunner test harness:

  • step limit
  • deterministic trace of stack deltas
  • snapshot of locals

• Add property tests (lightweight):

  • stack never underflows in verified programs
  • verified programs never jump out of bounds

Acceptance

• Debugging is fast, and regressions are caught.

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Definition of Done (DoD) for PBS v0 “minimum executable”

A single canonical cartridge runs end-to-end:

• let declarations (locals)
• arithmetic (+, -, *, /, %, comparisons)
• if/else control flow
• when expression (if present in lowering)
• function calls with params + returns (including void)
• multiple return slots (flattened structs / hardware value types)
• host syscalls (e.g., GfxClear565, InputPadSnapshot, InputTouchSnapshot)
• deterministic traps (OOB bounded, invalid local, invalid call target, stack underflow)