From 165b07757955514e1ad725b899e55fb8b1484133 Mon Sep 17 00:00:00 2001
From: Victor Giers <mail@victorgiers.com>
Date: Mon, 27 Apr 2026 15:46:33 +0200
Subject: [PATCH] Add unit tests for EditorSimulationController

---
 .../editor-simulation-controller.test.ts      | 161 ++++++++++++++++++
 1 file changed, 161 insertions(+)
 create mode 100644 tests/domain/editor-simulation-controller.test.ts

diff --git a/tests/domain/editor-simulation-controller.test.ts b/tests/domain/editor-simulation-controller.test.ts
new file mode 100644
index 00000000..897d83bd
--- /dev/null
+++ b/tests/domain/editor-simulation-controller.test.ts
@@ -0,0 +1,161 @@
+import { describe, expect, it, vi } from "vitest";
+
+import { createEmptySceneDocument } from "../../src/document/scene-document";
+import {
+  EditorSimulationController,
+  type EditorSimulationUiSnapshot
+} from "../../src/runtime-three/editor-simulation-controller";
+import { buildRuntimeSceneFromDocument } from "../../src/runtime-three/runtime-scene-build";
+
+function createManualFrameController(options: {
+  uiSnapshotIntervalSeconds?: number;
+  onBuild?: () => void;
+} = {}) {
+  return new EditorSimulationController({
+    uiSnapshotIntervalSeconds: options.uiSnapshotIntervalSeconds,
+    requestAnimationFrame: () => 1,
+    cancelAnimationFrame: () => undefined,
+    buildRuntimeScene: (document, buildOptions) => {
+      options.onBuild?.();
+      return buildRuntimeSceneFromDocument(document, buildOptions);
+    }
+  });
+}
+
+describe("EditorSimulationController", () => {
+  it("advances the editor clock only while playing", () => {
+    const document = createEmptySceneDocument();
+    document.time.dayLengthMinutes = 24;
+    document.time.startTimeOfDayHours = 6;
+    const controller = createManualFrameController();
+    controller.updateInputs({
+      document,
+      loadedModelAssets: {}
+    });
+
+    const initialClock = controller.getUiSnapshot().clock;
+    expect(initialClock?.timeOfDayHours).toBe(6);
+
+    controller.play();
+    controller.advance(60);
+
+    const playingClock = controller.getUiSnapshot().clock;
+    expect(playingClock?.timeOfDayHours).toBeGreaterThan(6);
+
+    controller.pause();
+    controller.advance(60);
+
+    expect(controller.getUiSnapshot().clock).toEqual(playingClock);
+  });
+
+  it("publishes coarse UI snapshots at a bounded tick rate", () => {
+    const document = createEmptySceneDocument();
+    const controller = createManualFrameController({
+      uiSnapshotIntervalSeconds: 0.5
+    });
+    const snapshots: EditorSimulationUiSnapshot[] = [];
+
+    controller.updateInputs({
+      document,
+      loadedModelAssets: {}
+    });
+    controller.subscribeUiSnapshot((snapshot) => {
+      snapshots.push(snapshot);
+    });
+    snapshots.length = 0;
+
+    controller.play();
+    expect(snapshots).toHaveLength(1);
+    snapshots.length = 0;
+
+    controller.advance(0.2);
+    controller.advance(0.2);
+    expect(snapshots).toHaveLength(0);
+
+    controller.advance(0.1);
+    expect(snapshots).toHaveLength(1);
+  });
+
+  it("rebuilds the cached base simulation scene only when inputs change", () => {
+    let buildCount = 0;
+    const document = createEmptySceneDocument();
+    const loadedModelAssets = {};
+    const controller = createManualFrameController({
+      onBuild: () => {
+        buildCount += 1;
+      }
+    });
+
+    controller.updateInputs({
+      document,
+      loadedModelAssets
+    });
+    expect(buildCount).toBe(1);
+
+    controller.play();
+    controller.advance(0.1);
+    controller.advance(0.1);
+    expect(buildCount).toBe(1);
+
+    controller.updateInputs({
+      document,
+      loadedModelAssets
+    });
+    expect(buildCount).toBe(1);
+
+    const renamedDocument = {
+      ...document,
+      name: "Rebuilt Scene"
+    };
+    controller.updateInputs({
+      document: renamedDocument,
+      loadedModelAssets
+    });
+    expect(buildCount).toBe(2);
+
+    const retimedDocument = {
+      ...renamedDocument,
+      time: {
+        ...renamedDocument.time,
+        dayLengthMinutes: 12
+      }
+    };
+    controller.updateInputs({
+      document: retimedDocument,
+      loadedModelAssets
+    });
+    expect(buildCount).toBe(3);
+
+    controller.updateInputs({
+      document: retimedDocument,
+      loadedModelAssets: {}
+    });
+    expect(buildCount).toBe(4);
+  });
+
+  it("emits frame updates without publishing a UI snapshot every frame", () => {
+    const document = createEmptySceneDocument();
+    const controller = createManualFrameController({
+      uiSnapshotIntervalSeconds: 1
+    });
+    const frameListener = vi.fn();
+    const uiListener = vi.fn();
+
+    controller.updateInputs({
+      document,
+      loadedModelAssets: {}
+    });
+    controller.subscribeFrame(frameListener);
+    controller.subscribeUiSnapshot(uiListener);
+    frameListener.mockClear();
+    uiListener.mockClear();
+
+    controller.play();
+    uiListener.mockClear();
+    controller.advance(0.25);
+    controller.advance(0.25);
+
+    expect(frameListener).toHaveBeenCalledTimes(2);
+    expect(uiListener).not.toHaveBeenCalled();
+  });
+});