diff --git a/tests/domain/entity.command.test.ts b/tests/domain/entity.command.test.ts
new file mode 100644
index 00000000..69ad36d3
--- /dev/null
+++ b/tests/domain/entity.command.test.ts
@@ -0,0 +1,94 @@
+import { describe, expect, it } from "vitest";
+
+import { createEditorStore } from "../../src/app/editor-store";
+import { createUpsertEntityCommand } from "../../src/commands/upsert-entity-command";
+import { createSoundEmitterEntity, createTriggerVolumeEntity } from "../../src/entities/entity-instances";
+
+describe("typed entity upsert command", () => {
+  it("places a Sound Emitter and restores the previous tool mode across undo and redo", () => {
+    const store = createEditorStore();
+    const soundEmitter = createSoundEmitterEntity({
+      position: {
+        x: 1,
+        y: 2,
+        z: 3
+      },
+      radius: 5,
+      gain: 0.5
+    });
+
+    store.setToolMode("box-create");
+    store.executeCommand(
+      createUpsertEntityCommand({
+        entity: soundEmitter,
+        label: "Place sound emitter"
+      })
+    );
+
+    expect(store.getState().toolMode).toBe("select");
+    expect(store.getState().selection).toEqual({
+      kind: "entities",
+      ids: [soundEmitter.id]
+    });
+    expect(store.getState().document.entities[soundEmitter.id]).toEqual(soundEmitter);
+
+    expect(store.undo()).toBe(true);
+    expect(store.getState().toolMode).toBe("box-create");
+    expect(store.getState().document.entities).toEqual({});
+
+    expect(store.redo()).toBe(true);
+    expect(store.getState().toolMode).toBe("select");
+    expect(store.getState().document.entities[soundEmitter.id]).toEqual(soundEmitter);
+  });
+
+  it("updates an existing Trigger Volume without changing its entity id", () => {
+    const store = createEditorStore();
+    const triggerVolume = createTriggerVolumeEntity({
+      id: "entity-trigger-main",
+      size: {
+        x: 2,
+        y: 2,
+        z: 2
+      }
+    });
+    const movedTriggerVolume = createTriggerVolumeEntity({
+      ...triggerVolume,
+      position: {
+        x: 4,
+        y: 1,
+        z: -2
+      },
+      size: {
+        x: 3,
+        y: 4,
+        z: 5
+      },
+      triggerOnEnter: false,
+      triggerOnExit: true
+    });
+
+    store.executeCommand(
+      createUpsertEntityCommand({
+        entity: triggerVolume,
+        label: "Place trigger volume"
+      })
+    );
+    store.setToolMode("box-create");
+    store.executeCommand(
+      createUpsertEntityCommand({
+        entity: movedTriggerVolume,
+        label: "Update trigger volume"
+      })
+    );
+
+    expect(store.getState().toolMode).toBe("select");
+    expect(store.getState().document.entities[triggerVolume.id]).toEqual(movedTriggerVolume);
+
+    expect(store.undo()).toBe(true);
+    expect(store.getState().toolMode).toBe("box-create");
+    expect(store.getState().document.entities[triggerVolume.id]).toEqual(triggerVolume);
+
+    expect(store.redo()).toBe(true);
+    expect(store.getState().document.entities[triggerVolume.id]).toEqual(movedTriggerVolume);
+  });
+});