Add tests for cache adapter

Author: socsieng

.vscode/settings.json

@@ -3,5 +3,6 @@
     "**/.turbo": true
   },
   "tailwindCSS.classAttributes": ["class", "className", "tw"],
-  "prettier.trailingComma": "all"
+  "prettier.trailingComma": "all",
+  "editor.formatOnSave": true,
 }

packages/tests-unit/tests/adapters/cache.test.ts

@@ -1,4 +1,5 @@
-import { hasCacheExtension } from "@opennextjs/aws/adapters/cache.js";
+import S3Cache, { hasCacheExtension } from "@opennextjs/aws/adapters/cache.js";
+import { vi } from "vitest";
 
 describe("hasCacheExtension", () => {
   it("Should returns true if has an extension and it is a CacheExtension", () => {
@@ -13,3 +14,58 @@ describe("hasCacheExtension", () => {
     expect(hasCacheExtension("hello,json")).toBeFalsy();
   });
 });
+
+describe("S3Cache", () => {
+  let cache: S3Cache;
+
+  const getFetchCacheSpy = vi.spyOn(S3Cache.prototype, "getFetchCache");
+  const getIncrementalCache = vi.spyOn(
+    S3Cache.prototype,
+    "getIncrementalCache",
+  );
+
+  beforeEach(() => {
+    cache = new S3Cache({
+      _appDir: false,
+      _requestHeaders: undefined as never,
+    });
+
+    globalThis.disableIncrementalCache = false;
+    vi.clearAllMocks();
+  });
+
+  it("Should return null when incremental cache is disabled", async () => {
+    globalThis.disableIncrementalCache = true;
+
+    const result = await cache.get("key");
+
+    expect(result).toBeNull();
+  });
+
+  it("Should return null for cache miss", async () => {
+    const result = await cache.get("key");
+
+    expect(result).toBeNull();
+  });
+
+  it("Should retrieve cache from fetch cache when fetch cache is true", async () => {
+    await cache.get("key", { fetchCache: true });
+
+    expect(getFetchCacheSpy).toHaveBeenCalled();
+  });
+
+  it("Should retrieve cache from fetch cache when hint is fetch", async () => {
+    await cache.get("key", { kindHint: "fetch" });
+
+    expect(getFetchCacheSpy).toHaveBeenCalled();
+  });
+
+  it.each(["app", "page", undefined])(
+    "Should retrieve cache from incremental cache when hint is not fetch: %s",
+    async (kindHint) => {
+      await cache.get("key", { kindHint: kindHint as any });
+
+      expect(getIncrementalCache).toHaveBeenCalled();
+    },
+  );
+});