establish-gameplay-test-harness

name	establish-gameplay-test-harness
description	Establish deterministic action, replay, state-digest, fixture, and fake-adapter test infrastructure in a standalone game. Use before gameplay implementation phases, not to implement features.

Establish the gameplay test harness

Scope

Build only G04 deterministic test infrastructure. Do not implement gameplay, persistence formats, native presentation, or game content.

Inputs

• Absolute FORGE_ROOT and external GAME_ROOT with valid locks/catalog.
• Current source-tree/runtime/platform/catalog hashes and prior G00-G03 evidence.
• Selected fixture world ID, release ID, and verified bundle hash.
• Stable minimal world fixture, semantic action fixture, and digest contract.
• G04 writable surface and exit gate.

Outputs

• Game-owned fixture, action runner, replay comparator, state digest, fake adapter, and failure-reproduction helpers under tests or src/game.
• Focused harness tests and Forge-owned evidence record.

Invariants

• Treat src/isoworld, runtime/platform locks, and bundles as immutable.
• Keep fixtures deterministic, portable, independent of wall time/native state, and free of save-file or gameplay-policy decisions.
• Never copy AGENTS.md, .agents, Forge skills, or phase evidence into GAME_ROOT.

Workflow

1. Read the G04 gate in docs/GAME_IMPLEMENTATION_PHASES.md.
2. Add game-owned fixtures/helpers under GAME_ROOT/tests or src/game.
3. Define semantic action sequences, integer ticks, and stable state digests.
4. Add replay equality, failure reproduction, and fake presentation-adapter tests.
5. Prove the harness from a working directory outside GAME_ROOT.

Completion

Complete when identical fixture/action inputs reproduce identical state hashes, a recorded failure reproduces, focused and shared headless tests pass, and the clean-game audit passes.