e2e: add open-graph image tests (#692)

* add og to app router

* add e2e

* md5 checksum

* review

examples/app-router/app/api/og/route.tsx

@@ -0,0 +1,72 @@
+import { ImageResponse } from "next/og";
+// App router includes @vercel/og.
+// No need to install it.
+// ?title=<title>
+
+export async function GET(request: Request) {
+  try {
+    const { searchParams } = new URL(request.url);
+
+    // ?title=<title>
+    const hasTitle = searchParams.has("title");
+    const title = hasTitle
+      ? searchParams.get("title")?.slice(0, 100)
+      : "My default title";
+
+    return new ImageResponse(
+      <div
+        style={{
+          backgroundColor: "black",
+          backgroundSize: "150px 150px",
+          height: "100%",
+          width: "100%",
+          display: "flex",
+          textAlign: "center",
+          alignItems: "center",
+          justifyContent: "center",
+          flexDirection: "column",
+          flexWrap: "nowrap",
+        }}
+      >
+        <div
+          style={{
+            display: "flex",
+            alignItems: "center",
+            justifyContent: "center",
+            justifyItems: "center",
+          }}
+        >
+          <img
+            alt="Vercel"
+            height={200}
+            src="data:image/svg+xml,%3Csvg width='116' height='100' fill='white' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M57.5 0L115 100H0L57.5 0z' /%3E%3C/svg%3E"
+            style={{ margin: "0 30px" }}
+            width={232}
+          />
+        </div>
+        <div
+          style={{
+            fontSize: 60,
+            fontStyle: "normal",
+            letterSpacing: "-0.025em",
+            color: "white",
+            marginTop: 30,
+            padding: "0 120px",
+            lineHeight: 1.4,
+            whiteSpace: "pre-wrap",
+          }}
+        >
+          {title}
+        </div>
+      </div>,
+      {
+        width: 1200,
+        height: 630,
+      },
+    );
+  } catch (e: any) {
+    return new Response("Failed to generate the image", {
+      status: 500,
+    });
+  }
+}

examples/app-router/app/og/opengraph-image.tsx

@@ -0,0 +1,36 @@
+import { ImageResponse } from "next/og";
+
+// Image metadata
+export const alt = "OpenNext";
+export const size = {
+  width: 1200,
+  height: 630,
+};
+
+export const contentType = "image/png";
+
+// Image generation
+export default async function Image() {
+  return new ImageResponse(
+    // ImageResponse JSX element
+    <div
+      style={{
+        fontSize: 128,
+        background: "white",
+        width: "100%",
+        height: "100%",
+        display: "flex",
+        alignItems: "center",
+        justifyContent: "center",
+      }}
+    >
+      OpenNext
+    </div>,
+    // ImageResponse options
+    {
+      // For convenience, we can re-use the exported opengraph-image
+      // size config to also set the ImageResponse's width and height.
+      ...size,
+    },
+  );
+}

examples/app-router/app/og/page.tsx

@@ -0,0 +1,3 @@
+export default function Page() {
+  return <div></div>;
+}

packages/tests-e2e/tests/appRouter/og.test.ts

@@ -0,0 +1,60 @@
+import { createHash } from "node:crypto";
+import { expect, test } from "@playwright/test";
+
+// This is the md5sums of the expected PNGs generated with `md5sum <file>`
+const OG_MD5 = "6e5e794ac0c27598a331690f96f05d00";
+const API_OG_MD5 = "cac95fc3e2d4d52870c0536bb18ba85b";
+
+function validateMd5(data: Buffer, expectedHash: string) {
+  return createHash("md5").update(data).digest("hex") === expectedHash;
+}
+
+test("Open-graph image to be in metatags and present", async ({
+  page,
+  request,
+}) => {
+  await page.goto("/og");
+
+  // Wait for meta tags to be present
+  const ogImageSrc = await page
+    .locator('meta[property="og:image"]')
+    .getAttribute("content");
+  const ogImageAlt = await page
+    .locator('meta[property="og:image:alt"]')
+    .getAttribute("content");
+  const ogImageType = await page
+    .locator('meta[property="og:image:type"]')
+    .getAttribute("content");
+  const ogImageWidth = await page
+    .locator('meta[property="og:image:width"]')
+    .getAttribute("content");
+  const ogImageHeight = await page
+    .locator('meta[property="og:image:height"]')
+    .getAttribute("content");
+
+  // Verify meta tag exists and is the correct values
+  expect(ogImageSrc).not.toBe(null);
+  expect(ogImageAlt).toBe("OpenNext");
+  expect(ogImageType).toBe("image/png");
+  expect(ogImageWidth).toBe("1200");
+  expect(ogImageHeight).toBe("630");
+
+  // Check if the image source is working
+  const response = await request.get(`/og/${ogImageSrc?.split("/").at(-1)}`);
+  expect(response.status()).toBe(200);
+  expect(response.headers()["content-type"]).toBe("image/png");
+  expect(response.headers()["cache-control"]).toBe(
+    "public, immutable, no-transform, max-age=31536000",
+  );
+  expect(validateMd5(await response.body(), OG_MD5)).toBe(true);
+});
+
+test("next/og (vercel/og) to work in API route", async ({ request }) => {
+  const response = await request.get("api/og?title=opennext");
+  expect(response.status()).toBe(200);
+  expect(response.headers()["content-type"]).toBe("image/png");
+  expect(response.headers()["cache-control"]).toBe(
+    "public, immutable, no-transform, max-age=31536000",
+  );
+  expect(validateMd5(await response.body(), API_OG_MD5)).toBe(true);
+});