Add unit tests for resolving viewport world state

tests/unit/viewport-simulation-membership.test.ts

@@ -1,7 +1,10 @@
 import { describe, expect, it } from "vitest";
 
+import { createDefaultProjectTimeSettings } from "../../src/document/project-time-settings";
+import { createDefaultWorldSettings } from "../../src/document/world-settings";
 import {
-  createViewportSimulationMembershipSignatures
+  createViewportSimulationMembershipSignatures,
+  resolveViewportWorldState
 } from "../../src/viewport-three/viewport-host";
 import type { RuntimeSceneDefinition } from "../../src/runtime-three/runtime-scene-build";
 
@@ -98,3 +101,64 @@ describe("createViewportSimulationMembershipSignatures", () => {
     ).not.toEqual(createViewportSimulationMembershipSignatures(runtimeScene));
   });
 });
+
+describe("resolveViewportWorldState", () => {
+  it("applies document project time when the runtime scene is unavailable", () => {
+    const world = createDefaultWorldSettings();
+    const time = createDefaultProjectTimeSettings();
+    time.startTimeOfDayHours = 0;
+    world.projectTimeLightingEnabled = true;
+    world.ambientLight = {
+      colorHex: "#ffffff",
+      intensity: 1
+    };
+    world.timeOfDay.night.ambientColorHex = "#101820";
+    world.timeOfDay.night.ambientIntensityFactor = 0.25;
+
+    const state = resolveViewportWorldState({
+      currentWorld: world,
+      currentDocument: { time },
+      currentSimulationScene: null,
+      currentSimulationClock: {
+        timeOfDayHours: 0,
+        dayCount: 0,
+        dayLengthMinutes: time.dayLengthMinutes
+      }
+    });
+
+    expect(state.resolvedTime?.dayPhase).toBe("night");
+    expect(state.resolvedWorld?.ambientLight).toEqual({
+      colorHex: "#101820",
+      intensity: 0.25
+    });
+  });
+
+  it("prefers runtime scene time settings when a runtime scene is available", () => {
+    const documentWorld = createDefaultWorldSettings();
+    const runtimeWorld = createDefaultWorldSettings();
+    const documentTime = createDefaultProjectTimeSettings();
+    const runtimeTime = createDefaultProjectTimeSettings();
+    documentTime.sunriseTimeOfDayHours = 6;
+    documentTime.sunsetTimeOfDayHours = 18;
+    runtimeTime.sunriseTimeOfDayHours = 10;
+    runtimeTime.sunsetTimeOfDayHours = 20;
+
+    const state = resolveViewportWorldState({
+      currentWorld: documentWorld,
+      currentDocument: { time: documentTime },
+      currentSimulationScene: {
+        time: runtimeTime,
+        world: runtimeWorld
+      },
+      currentSimulationClock: {
+        timeOfDayHours: 9,
+        dayCount: 0,
+        dayLengthMinutes: runtimeTime.dayLengthMinutes
+      }
+    });
+
+    expect(state.world).toBe(runtimeWorld);
+    expect(state.timeSettings).toBe(runtimeTime);
+    expect(state.resolvedTime?.dayPhase).toBe("night");
+  });
+});