Export __N_SSG and __N_SSP from the error component (vercel#3574)

`export *` would be preferable once supported.

crates/next-core/js/src/entry/error.tsx

@@ -1,4 +1,7 @@
-import Error, { getStaticProps } from "@vercel/turbopack-next/internal/_error";
-
-export default Error;
-export { getStaticProps };
+// TODO(alexkirsz) export * would be preferrable here once supported.
+export {
+  default,
+  getStaticProps,
+  __N_SSG,
+  __N_SSP,
+} from "@vercel/turbopack-next/internal/_error";

crates/next-dev-tests/test-harness/harness.ts

@@ -0,0 +1,107 @@
+import * as jest from "jest-circus-browser/dist/umd/jest-circus";
+import expectMod from "expect/build-es5/index";
+
+type CallSignature<T extends (...a: any[]) => unknown> = (
+  ...a: Parameters<T>
+) => ReturnType<T>;
+
+declare global {
+  var __jest__: typeof jest;
+  var expect: typeof expectMod;
+  // We need to extract only the call signature as `autoReady(jest.describe)` drops all the other properties
+  var describe: CallSignature<typeof jest.describe>;
+  var it: CallSignature<typeof jest.it>;
+  var READY: (arg: string) => void;
+  var nsObj: (obj: any) => any;
+
+  interface Window {
+    NEXT_HYDRATED?: boolean;
+    onNextHydrated?: () => void;
+  }
+}
+
+let isReady = false;
+function autoReady<T extends (...a: any[]) => unknown>(
+  fn: (...args: Parameters<T>) => ReturnType<T>
+): (...args: Parameters<T>) => ReturnType<T> {
+  return (...args) => {
+    if (!isReady) {
+      isReady = true;
+      setImmediate(() => {
+        READY("");
+      });
+    }
+    return fn(...args);
+  };
+}
+
+globalThis.__jest__ = jest;
+globalThis.expect = expectMod;
+globalThis.describe = autoReady(jest.describe);
+globalThis.it = autoReady(jest.it);
+
+// From https://github.com/webpack/webpack/blob/9fcaa243573005d6fdece9a3f8d89a0e8b399613/test/TestCases.template.js#L422
+globalThis.nsObj = function nsObj(obj) {
+  Object.defineProperty(obj, Symbol.toStringTag, {
+    value: "Module",
+  });
+  return obj;
+};
+
+function wait(ms: number): Promise<void> {
+  return new Promise((resolve) => {
+    setTimeout(resolve, ms);
+  });
+}
+
+async function waitForPath(contentWindow: Window, path: string): Promise<void> {
+  while (true) {
+    if (contentWindow.location.pathname === path) {
+      break;
+    }
+
+    await wait(1);
+  }
+}
+
+export function waitForHydration(
+  iframe: HTMLIFrameElement,
+  path: string
+): Promise<void> {
+  return new Promise((resolve) => {
+    if (
+      iframe.contentDocument != null &&
+      iframe.contentDocument.readyState === "complete"
+    ) {
+      waitForHydrationAndResolve(iframe.contentWindow!, path).then(resolve);
+    } else {
+      iframe.addEventListener("load", () => {
+        waitForHydrationAndResolve(iframe.contentWindow!, path).then(resolve);
+      });
+    }
+  });
+}
+
+async function waitForHydrationAndResolve(
+  contentWindow: Window,
+  path: string
+): Promise<void> {
+  await waitForPath(contentWindow, path);
+
+  return await new Promise((resolve) => {
+    if (contentWindow.NEXT_HYDRATED) {
+      resolve();
+    } else {
+      contentWindow.onNextHydrated = () => {
+        resolve();
+      };
+    }
+  });
+}
+
+export function markAsHydrated() {
+  window.NEXT_HYDRATED = true;
+  if (typeof window.onNextHydrated === "function") {
+    window.onNextHydrated();
+  }
+}

crates/next-dev/test-harness/package.json → crates/next-dev-tests/test-harness/package.json

@@ -2,9 +2,10 @@
   "name": "@turbo/pack-test-harness",
   "private": true,
   "version": "0.0.1",
-  "main": "./harness.js",
+  "main": "./harness.ts",
   "dependencies": {
     "expect": "^24.5.0",
+    "jest-circus": "^29.4.1",
     "jest-circus-browser": "^1.0.7"
   }
 }

crates/next-dev-tests/test-harness/types.d.ts

@@ -0,0 +1,7 @@
+declare module "jest-circus-browser/dist/umd/jest-circus" {
+  export * from "jest-circus";
+}
+
+declare module "expect/build-es5/index" {
+  export { default } from "expect";
+}

crates/next-dev-tests/tests/integration/next/404/navigate/input/pages/_error.tsx

@@ -0,0 +1,19 @@
+import { useEffect } from "react";
+
+export default function ErrorPage(props: { static: "static" }) {
+  useEffect(() => {
+    import("@turbo/pack-test-harness").then((harness) =>
+      harness.markAsHydrated()
+    );
+  });
+
+  return <div data-test-error>{props.static}</div>;
+}
+
+export function getStaticProps() {
+  return {
+    props: {
+      static: "static",
+    },
+  };
+}

crates/next-dev-tests/tests/integration/next/404/navigate/input/pages/index.tsx

@@ -0,0 +1,44 @@
+import { useEffect, useRef } from "react";
+
+export default function Page() {
+  const iframeRef = useRef<HTMLIFrameElement | null>(null);
+
+  useEffect(() => {
+    // Only run on client
+    import("@turbo/pack-test-harness").then((mod) =>
+      runTests(mod, iframeRef.current!)
+    );
+  });
+
+  return (
+    <iframe style={{ width: 800, height: 600 }} src="/link" ref={iframeRef} />
+  );
+}
+
+type Harness = typeof import("@turbo/pack-test-harness");
+
+function runTests(harness: Harness, iframe: HTMLIFrameElement) {
+  it("returns a 404 status code", async () => {
+    const res = await fetch("/not-found");
+    expect(res.status).toBe(404);
+  });
+
+  it("navigates to the 404 page", async () => {
+    await harness.waitForHydration(iframe, "/link");
+
+    const link = iframe.contentDocument!.querySelector("a[data-test-link]");
+    expect(link).not.toBeNull();
+    expect(link!).toBeInstanceOf(
+      (iframe.contentWindow as any).HTMLAnchorElement
+    );
+    expect(link!.textContent).toBe("Not found");
+
+    (link as HTMLAnchorElement).click();
+
+    await harness.waitForHydration(iframe, "/not-found");
+
+    const error = iframe.contentDocument!.querySelector("[data-test-error]");
+    expect(error).not.toBeNull();
+    expect(error!.textContent).toBe("static");
+  });
+}

crates/next-dev-tests/tests/integration/next/404/navigate/input/pages/link.tsx

@@ -0,0 +1,14 @@
+import Link from "next/link";
+import { useEffect } from "react";
+
+export default function Page() {
+  useEffect(() => {
+    import("@turbo/pack-test-harness").then((mod) => mod.markAsHydrated());
+  });
+
+  return (
+    <Link href="/not-found" data-test-link>
+      Not found
+    </Link>
+  );
+}

crates/next-dev-tests/tests/integration/next/404/navigate/input/pages/not-found.tsx

@@ -0,0 +1,9 @@
+export default function Page() {
+  return <div>Page</div>;
+}
+
+export function getStaticProps() {
+  return {
+    notFound: true,
+  };
+}

crates/next-dev-tests/tests/integration/next/app/metadata/input/tsconfig.json

@@ -19,7 +19,10 @@
       {
         "name": "next"
       }
-    ]
+    ],
+    "paths": {
+      "@turbo/pack-test-harness": ["../../../../../../test-harness"]
+    }
   },
   "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
   "exclude": ["node_modules"]

crates/next-dev-tests/tests/integration/next/tailwind/basic/input/tsconfig.json

@@ -13,7 +13,10 @@
     "resolveJsonModule": true,
     "isolatedModules": true,
     "jsx": "preserve",
-    "incremental": true
+    "incremental": true,
+    "paths": {
+      "@turbo/pack-test-harness": ["../../../../../../test-harness"]
+    }
   },
   "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", "pages/index.jsx"],
   "exclude": ["node_modules"]

crates/next-dev-tests/tests/package.json

@@ -2,7 +2,8 @@
   "name": "next-dev-tests",
   "private": true,
   "devDependencies": {
-    "@turbo/pack-test-harness": "*",
+    "@types/jest": "29.4.0",
+    "@turbo/pack-test-harness": "file:../test-harness",
     "autoprefixer": "^10.4.13",
     "loader-runner": "^4.3.0",
     "next": "13.1.7-canary.2",

crates/next-dev-tests/tests/tsconfig.json

@@ -0,0 +1,35 @@
+{
+  "compilerOptions": {
+    // type checking
+    "strict": true,
+    "noFallthroughCasesInSwitch": true,
+    "skipLibCheck": true,
+
+    // interop constraints
+    "allowSyntheticDefaultImports": true,
+    "esModuleInterop": true,
+
+    // js support
+    "allowJs": true,
+    "checkJs": false,
+
+    // environment
+    "jsx": "react-jsx",
+    "lib": ["ESNext", "DOM"],
+    "target": "esnext",
+
+    // modules
+    "baseUrl": ".",
+    "module": "esnext",
+    "moduleResolution": "node",
+
+    "paths": {
+      "@turbo/pack-test-harness": ["../test-harness"]
+    },
+
+    // emit
+    "noEmit": true,
+    "stripInternal": true
+  },
+  "include": ["integration"]
+}