import nextConfig from "../next.config";

describe("next.config", () => {
  it("does not announce the framework in the X-Powered-By header", () => {
    expect(nextConfig.poweredByHeader).toBe(false);
  });

  it("serves AVIF before WebP, because the browser takes the first format of the list it accepts", () => {
    expect(nextConfig.images?.formats).toEqual(["image/avif", "image/webp"]);
  });

  it("leaves the image cache time to the framework default instead of revalidating every minute", () => {
    expect(nextConfig.images).not.toHaveProperty("minimumCacheTTL");
  });

  it("keeps the CSP in Report-Only (Google Ads is allowed in it now, but the owner activates it later), never enforcing it by accident", async () => {
    const rules = (await nextConfig.headers?.()) ?? [];
    const site = rules.find(({ source }) => source === "/(.*)");
    const names = site?.headers.map(({ key }) => key) ?? [];

    expect(names).toContain("Content-Security-Policy-Report-Only");
    expect(names).not.toContain("Content-Security-Policy");
  });
});