Conformance suite

pytest tests (15 of them) that assert an emulator correctly implements the control contract (../SPEC.md, 0.3.x). Point them at any emulator — the reference x16emu, FAB, the Neo6502, the PC-FX (Mednafen) fork — and they check the same surface. Tests gated above the emulator's advertised contract skip automatically, so a 0.1-only backend still passes. Platform-agnostic: framebuffer dimensions come from the PPM header, addresses use $0000, and bank is exercised without requiring the platform to have banking.

Run

Attach to an already-running emulator:

RRDC_PORT=8080 pytest -v

Or let the suite launch one ({port} is substituted into the command):

RRDC_EMU_CMD="SDL_VIDEODRIVER=dummy SDL_AUDIODRIVER=dummy \
    /path/to/x16emu -rom rom.bin -warp -controlport {port}" \
RRDC_PORT=8391 pytest -v

If nothing is listening and no RRDC_EMU_CMD is set, the tests skip (a bare pytest in CI without an emulator is a skip, not a failure).

What it checks

• /status — required keys present, contract MAJOR matches, sane types.
• /regs — a non-empty JSON object of integer registers.
• /mem — returns exactly len bytes; honours bank.
• /screenshot — a well-formed PPM whose body size matches its dimensions.
• /step — deterministic: equal steps advance the frame counter by equal, positive amounts, and /step returns the halted counter.
• /pause + /resume — toggle the paused state.
• /key (0.2) — accepts text=/code= with optional down=, rejects a request with neither; is POST-only.
• /reset (0.2) — resets and returns {"reset":true}.
• POST /mem (0.3) — write→read round-trips; is POST-only.
• /audio (0.3) — returns a well-formed PCM WAV.
• Errors — unknown path → 404; GET /step / GET /key → 405.

Environment

Requires pytest. Nothing else — the client is stdlib-only (Pillow is optional and unused here).