unity-testability

name

unity-testability

description

Use when deciding how to make Ankhora gameplay logic testable, isolating logic out of MonoBehaviour, or choosing between EditMode and PlayMode tests. Especially for the record/replay core (serialising hand poses, timeline stepping, annotation/anchor data) which should be plain C# and EditMode-tested. Triggers: testability, how to test this, write a test, unit test, EditMode, PlayMode, isolate logic, mockable, record replay logic, dependency injection in Unity.

Unity testability (Ankhora)

CI runs unity-test-runner (EditMode) — it compiles the project and runs tests without BuildPlayer (@CLAUDE.md § What "build"/"run"/"test" mean today). EditMode tests are therefore the cheap, fast safety net. The goal of this skill: keep Ankhora's logic in a shape where that net actually catches things.

The core principle

Push decisions into plain C# classes; keep MonoBehaviour thin. A MonoBehaviour should mostly gather Unity input (poses, time, events) and delegate to a pure class that holds the actual rule. The pure class is what you unit-test in EditMode.

This matters most for Ankhora's record/replay core: capturing a hand-pose stream, stepping a timeline, diffing learner vs. expert, (de)serialising a masterclass. None of that needs a live scene — it is data transformation, ideal for EditMode tests.

Testability checklist (ask before writing the class)

• Can the rule/algorithm run without Transform, GameObject, or scene state? → If yes, put it in a plain C# class (no MonoBehaviour base).
• Is time injected (a float deltaTime / timestamp parameter) rather than read from Time.deltaTime inside the logic? → Inject it, so tests can drive the timeline deterministically.
• Is configuration passed in (constructor / method args / a ScriptableObject handed over) instead of read through static singletons? → Inject it.
• Does this genuinely need a running scene (physics, frame loop, real input)? → Only then reach for a PlayMode test. Default to EditMode.

Shape to aim for

// Pure, EditMode-testable: no UnityEngine scene dependencies in the logic.
public sealed class ReplayTimeline
{
    public PoseFrame Sample(float tSeconds) { /* deterministic */ }
}

// Thin MonoBehaviour: gathers Unity state, delegates, applies the result.
public sealed class ReplayPlayer : MonoBehaviour
{
    [SerializeField] private GhostHands ghostHands;
    private ReplayTimeline timeline;
    private void Update() => ghostHands.Apply(timeline.Sample(Time.time));
}

Where tests live

• EditMode: Assets/Tests/EditMode/ (assembly Ankhora.Tests.EditMode, Editor-only).
• PlayMode: Assets/Tests/PlayMode/ (create when a test genuinely needs the frame loop).

Note: .meta files for test assets are being normalised on fix/unity-test-metas. When adding test files, ensure each .cs has a committed .meta (the unity-test-author agent handles this).

Hand off

For actually authoring the tests, dispatch the unity-test-author agent — this skill decides what shape the code should take; that agent writes the tests against it.