Add tests and update messages for autosave functionality

tests/unit/editor-autosave.test.ts

@@ -0,0 +1,77 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { EditorAutosaveController } from "../../src/serialization/editor-autosave";
+
+describe("EditorAutosaveController", () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("debounces repeated autosave schedules into one save", () => {
+    const saveDraft = vi.fn(() => ({
+      status: "saved" as const,
+      message: "Autosave updated."
+    }));
+    const autosave = new EditorAutosaveController({
+      debounceMs: 200,
+      saveDraft
+    });
+
+    autosave.schedule();
+    autosave.schedule();
+    autosave.schedule();
+
+    vi.advanceTimersByTime(199);
+    expect(saveDraft).not.toHaveBeenCalled();
+
+    vi.advanceTimersByTime(1);
+    expect(saveDraft).toHaveBeenCalledTimes(1);
+  });
+
+  it("flushes a pending autosave immediately", () => {
+    const saveDraft = vi.fn(() => ({
+      status: "saved" as const,
+      message: "Autosave updated."
+    }));
+    const autosave = new EditorAutosaveController({
+      debounceMs: 200,
+      saveDraft
+    });
+
+    autosave.schedule();
+    const flushResult = autosave.flush();
+
+    expect(flushResult).toEqual({
+      status: "saved",
+      message: "Autosave updated."
+    });
+    expect(saveDraft).toHaveBeenCalledTimes(1);
+
+    vi.advanceTimersByTime(200);
+    expect(saveDraft).toHaveBeenCalledTimes(1);
+  });
+
+  it("reports autosave failures through the completion callback", () => {
+    const onComplete = vi.fn();
+    const autosave = new EditorAutosaveController({
+      debounceMs: 100,
+      onComplete,
+      saveDraft: () => ({
+        status: "error" as const,
+        message: "Autosave could not be saved. quota exceeded"
+      })
+    });
+
+    autosave.schedule();
+    vi.advanceTimersByTime(100);
+
+    expect(onComplete).toHaveBeenCalledWith({
+      status: "error",
+      message: "Autosave could not be saved. quota exceeded"
+    });
+  });
+});