prometeu-runtime/discussion/workflow/plans/PLN-0114-add-deterministic-render-worker-test-harness.md

id	ticket	title	status	created	completed	ref_decisions	tags
PLN-0114	real-render-worker-establishment	Add Deterministic Render Worker Test Harness	done	2026-06-15		DEC-0033	runtime renderer worker tests concurrency

Briefing

DEC-0033 requires worker behavior to be proven without a native window and without fragile sleeps. This plan creates reusable deterministic test fixtures for the remaining worker plans.

Decisions de Origem

• DEC-0033: Real Render Worker Contract.

Alvo

Add a fake backend and synchronization harness capable of blocking render at controlled points, observing publication, and proving non-blocking VM/producer behavior.

Escopo

• Create test-only synchronization helpers using barriers/condvars.
• Create a fake render backend shape that can block/fail/publish deterministically.
• Add helper functions for constructing owned render submissions and frames.
• Reuse the harness in later worker tests.

Fora de Escopo

• No production worker lifecycle.
• No desktop host integration.
• No real GFX rasterization.

Plano de Execucao

Step 1 - Add test support module

What: Introduce deterministic worker test fixtures. How: Add test-only helpers under prometeu-system worker tests or a local test module. File(s): crates/console/prometeu-system/src/services/vm_runtime/*.

Step 2 - Add controllable fake backend

What: Provide backend behavior for tests. How: Fake backend can block at render start, unblock by test signal, return errors, and record published frames. File(s): worker test module.

Step 3 - Add submission/frame builders

What: Make tests concise and consistent. How: Build Game/Shell submissions with explicit frame ids and ownership metadata; build OwnedRgba8888Frame fixtures. File(s): worker test module.

Step 4 - Add initial harness self-tests

What: Prove harness itself is deterministic. How: Verify a test can block and release backend render without timing sleeps. File(s): worker test module.

Criterios de Aceite

• Tests can block worker backend render using deterministic synchronization.
• Tests can observe published OwnedRgba8888Frame values.
• Harness can inject backend errors.
• Harness helpers are scoped to tests or clearly internal.

Tests / Validacao

• cargo test -p prometeu-system render_worker
• rg "sleep\\(|thread::sleep" crates/console/prometeu-system/src/services/vm_runtime -n

Riscos

• Test harness code can become too coupled to implementation internals.
• Overly broad helpers can hide important assertions in later plans.