fix(FN-XXX): align tui startup update check

packages/cli/src/__tests__/update-cache.test.ts

@@ -0,0 +1,57 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import { mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { readFileSync } from "node:fs";
+
+const CLI_PACKAGE_VERSION = (
+  JSON.parse(readFileSync(new URL("../../package.json", import.meta.url), "utf-8")) as { version: string }
+).version;
+
+const cacheDir = "/tmp/fusion-update-cache-test";
+
+const { mockResolveGlobalDir } = vi.hoisted(() => ({
+  mockResolveGlobalDir: vi.fn().mockReturnValue("/tmp/fusion-update-cache-test"),
+}));
+
+vi.mock("@fusion/core", () => ({
+  resolveGlobalDir: mockResolveGlobalDir,
+  GlobalSettingsStore: vi.fn(),
+}));
+
+const { getCachedUpdateStatus } = await import("../update-cache.js");
+
+function writeUpdateCache(payload: { updateAvailable: boolean; latestVersion: string; currentVersion: string }): void {
+  mkdirSync(cacheDir, { recursive: true });
+  writeFileSync(`${cacheDir}/update-check.json`, JSON.stringify(payload), "utf-8");
+}
+
+beforeEach(() => {
+  rmSync(cacheDir, { recursive: true, force: true });
+  mockResolveGlobalDir.mockReset();
+  mockResolveGlobalDir.mockReturnValue(cacheDir);
+});
+
+describe("getCachedUpdateStatus", () => {
+  it("returns the cached update when it matches the installed CLI version", () => {
+    writeUpdateCache({
+      updateAvailable: true,
+      currentVersion: CLI_PACKAGE_VERSION,
+      latestVersion: "9.9.9",
+    });
+
+    expect(getCachedUpdateStatus(CLI_PACKAGE_VERSION)).toEqual({
+      updateAvailable: true,
+      currentVersion: CLI_PACKAGE_VERSION,
+      latestVersion: "9.9.9",
+    });
+  });
+
+  it("ignores stale cached updates from a different installed CLI version", () => {
+    writeUpdateCache({
+      updateAvailable: true,
+      currentVersion: "0.0.1",
+      latestVersion: "9.9.9",
+    });
+
+    expect(getCachedUpdateStatus(CLI_PACKAGE_VERSION)).toBeNull();
+  });
+});