Support for i18n in Next 10 (#75)

* rough pass at i18n ssg breaking changes in next 10

* update withoutProps/redirects to accommodate defaultLocale

* very dirty Just Working i18n for most cases

* pre clean-up tests, no cypress yet

* make i18n getDataRoute helper more DRY

* fix windows test

* add documentation for withoutProps and SSR pages logic for i18n

* clean up getStaticProps setup logic

* fix getStaticProps redirects logic to be consistent with setup and heavily comment

* fix revalidate redirects logic and heavily comment

* remove superfluous getDataRouteForI18nRoute helper

* remove superfluous getFilePathForRouteWithI18n helper

* fix existing cypress tests except a few v odd cases

* fix/move fallback i18n logic

* fix previously commented out failing dataRoute tests

* fix 404 cypress tests which expect root level 404.html

* specifically test i18n/non-default locales in cypress

* root level index pages need special dataRoute logic

* use splats for dynamic ssg i18n dataRoutes

* plain static routes need 2 redirects: one to defaultLocale, one to preview mode func

* massive cleanup/refactor to transform manifest

* missing initialProps + fallback logic + PR feedback

cypress/fixtures/next.config.js

@@ -1,3 +1,3 @@
 module.exports = {
-  target: "serverless",
+  target: "experimental-serverless-trace",
 };

cypress/fixtures/next.config.js-with-i18n

@@ -0,0 +1,7 @@
+module.exports = {
+  target: "experimental-serverless-trace",
+  i18n: {
+    locales: ["en", "fr"],
+    defaultLocale: "en"
+  }
+};

cypress/fixtures/pages-with-i18n/api/enterPreview.js

@@ -0,0 +1,12 @@
+export default async function preview(req, res) {
+  const { query } = req;
+  const { id } = query;
+
+  // Enable Preview Mode by setting the cookies
+  res.setPreviewData({});
+
+  // Redirect to the path from the fetched post
+  // We don't redirect to req.query.slug as that might lead to open redirect vulnerabilities
+  res.writeHead(307, { Location: `/previewTest/${id}` });
+  res.end();
+}

cypress/fixtures/pages-with-i18n/api/enterPreviewStatic.js

@@ -0,0 +1,12 @@
+export default async function preview(req, res) {
+  const { query } = req;
+  const { id } = query;
+
+  // Enable Preview Mode by setting the cookies
+  res.setPreviewData({});
+
+  // Redirect to the path from the fetched post
+  // We don't redirect to req.query.slug as that might lead to open redirect vulnerabilities
+  res.writeHead(307, { Location: `/previewTest/static` });
+  res.end();
+}

cypress/fixtures/pages-with-i18n/api/exitPreview.js

@@ -0,0 +1,8 @@
+export default async function exit(_, res) {
+  // Exit the current user from "Preview Mode". This function accepts no args.
+  res.clearPreviewData();
+
+  // Redirect the user back to the index page.
+  res.writeHead(307, { Location: "/" });
+  res.end();
+}

cypress/fixtures/pages-with-i18n/api/redirect.js

@@ -0,0 +1,6 @@
+export default async function preview(req, res) {
+  const { query } = req;
+  const { to } = query;
+
+  res.redirect(`/shows/${to}`);
+}

cypress/fixtures/pages-with-i18n/api/shows/[...params].js

@@ -0,0 +1,23 @@
+export default async (req, res) => {
+  // Get the params and query string parameters
+  const { query } = req;
+  const { params, ...queryStringParams } = query;
+
+  // Get the ID of the show
+  const id = params[0];
+
+  // Get the data
+  const fetchRes = await fetch(`https://api.tvmaze.com/shows/${id}`);
+  const data = await fetchRes.json();
+
+  // If show was found, return it
+  if (fetchRes.status == 200) {
+    res.status(200);
+    res.json({ params, queryStringParams, show: data });
+  }
+  // If show was not found, return error
+  else {
+    res.status(404);
+    res.json({ error: "Show not found" });
+  }
+};

cypress/fixtures/pages-with-i18n/api/shows/[id].js

@@ -0,0 +1,20 @@
+export default async (req, res) => {
+  // Get the ID of the show
+  const { query } = req;
+  const { id } = query;
+
+  // Get the data
+  const fetchRes = await fetch(`https://api.tvmaze.com/shows/${id}`);
+  const data = await fetchRes.json();
+
+  // If show was found, return it
+  if (fetchRes.status == 200) {
+    res.status(200);
+    res.json({ show: data });
+  }
+  // If show was not found, return error
+  else {
+    res.status(404);
+    res.json({ error: "Show not found" });
+  }
+};

cypress/fixtures/pages-with-i18n/api/static.js

@@ -0,0 +1,7 @@
+export default (req, res) => {
+  // We can set custom headers
+  res.setHeader("My-Custom-Header", "header123");
+
+  res.status(200);
+  res.json({ message: "hello world :)" });
+};

cypress/fixtures/pages-with-i18n/getServerSideProps/[id].js

@@ -0,0 +1,54 @@
+import Error from "next/error";
+import Link from "next/link";
+
+const Show = ({ errorCode, show }) => {
+  // If show item was not found, render 404 page
+  if (errorCode) {
+    return <Error statusCode={errorCode} />;
+  }
+
+  // Otherwise, render show
+  return (
+    <div>
+      <p>
+        This page uses getInitialProps() to fetch the show with the ID provided
+        in the URL: /shows/:id
+        <br />
+        Refresh the page to see server-side rendering in action.
+        <br />
+        You can also try changing the ID to any other number between 1-10000.
+      </p>
+
+      <hr />
+
+      <h1>Show #{show.id}</h1>
+      <p>{show.name}</p>
+
+      <hr />
+
+      <Link href="/">
+        <a>Go back home</a>
+      </Link>
+    </div>
+  );
+};
+
+export const getServerSideProps = async ({ params }) => {
+  // The ID to render
+  const { id } = params;
+
+  const res = await fetch(`https://api.tvmaze.com/shows/${id}`);
+  const data = await res.json();
+
+  // Set error code if show item could not be found
+  const errorCode = res.status > 200 ? res.status : false;
+
+  return {
+    props: {
+      errorCode,
+      show: data,
+    },
+  };
+};
+
+export default Show;

cypress/fixtures/pages-with-i18n/getServerSideProps/catch/all/[...slug].js

@@ -0,0 +1,55 @@
+import Error from "next/error";
+import Link from "next/link";
+
+const Show = ({ errorCode, show }) => {
+  // If show item was not found, render 404 page
+  if (errorCode) {
+    return <Error statusCode={errorCode} />;
+  }
+
+  // Otherwise, render show
+  return (
+    <div>
+      <p>
+        This page uses getInitialProps() to fetch the show with the ID provided
+        in the URL: /shows/:id
+        <br />
+        Refresh the page to see server-side rendering in action.
+        <br />
+        You can also try changing the ID to any other number between 1-10000.
+      </p>
+
+      <hr />
+
+      <h1>Show #{show.id}</h1>
+      <p>{show.name}</p>
+
+      <hr />
+
+      <Link href="/">
+        <a>Go back home</a>
+      </Link>
+    </div>
+  );
+};
+
+export const getServerSideProps = async ({ params }) => {
+  // The ID to render
+  const { slug } = params;
+  const id = slug[0];
+
+  const res = await fetch(`https://api.tvmaze.com/shows/${id}`);
+  const data = await res.json();
+
+  // Set error code if show item could not be found
+  const errorCode = res.status > 200 ? res.status : false;
+
+  return {
+    props: {
+      errorCode,
+      show: data,
+    },
+  };
+};
+
+export default Show;

cypress/fixtures/pages-with-i18n/getServerSideProps/static.js

@@ -0,0 +1,38 @@
+import Link from "next/link";
+
+const Show = ({ show }) => (
+  <div>
+    <p>
+      This page uses getInitialProps() to fetch the show with the ID provided in
+      the URL: /shows/:id
+      <br />
+      Refresh the page to see server-side rendering in action.
+      <br />
+      You can also try changing the ID to any other number between 1-10000.
+    </p>
+
+    <hr />
+
+    <h1>Show #{show.id}</h1>
+    <p>{show.name}</p>
+
+    <hr />
+
+    <Link href="/">
+      <a>Go back home</a>
+    </Link>
+  </div>
+);
+
+export const getServerSideProps = async ({ params }) => {
+  const res = await fetch("https://api.tvmaze.com/shows/42");
+  const data = await res.json();
+
+  return {
+    props: {
+      show: data,
+    },
+  };
+};
+
+export default Show;

cypress/fixtures/pages-with-i18n/getStaticProps/[id].js

@@ -0,0 +1,43 @@
+import Link from "next/link";
+
+const Show = ({ show }) => (
+  <div>
+    <p>This page uses getStaticProps() to pre-fetch a TV show.</p>
+
+    <hr />
+
+    <h1>Show #{show.id}</h1>
+    <p>{show.name}</p>
+
+    <hr />
+
+    <Link href="/">
+      <a>Go back home</a>
+    </Link>
+  </div>
+);
+
+export async function getStaticPaths() {
+  // Set the paths we want to pre-render
+  const paths = [{ params: { id: "1" } }, { params: { id: "2" } }];
+
+  // We'll pre-render only these paths at build time.
+  // { fallback: false } means other routes should 404.
+  return { paths, fallback: false };
+}
+
+export async function getStaticProps({ params }) {
+  // The ID to render
+  const { id } = params;
+
+  const res = await fetch(`https://api.tvmaze.com/shows/${id}`);
+  const data = await res.json();
+
+  return {
+    props: {
+      show: data,
+    },
+  };
+}
+
+export default Show;

cypress/fixtures/pages-with-i18n/getStaticProps/static.js

@@ -0,0 +1,31 @@
+import Link from "next/link";
+
+const Show = ({ show }) => (
+  <div>
+    <p>This page uses getStaticProps() to pre-fetch a TV show.</p>
+
+    <hr />
+
+    <h1>Show #{show.id}</h1>
+    <p>{show.name}</p>
+
+    <hr />
+
+    <Link href="/">
+      <a>Go back home</a>
+    </Link>
+  </div>
+);
+
+export async function getStaticProps(context) {
+  const res = await fetch(`https://api.tvmaze.com/shows/71`);
+  const data = await res.json();
+
+  return {
+    props: {
+      show: data,
+    },
+  };
+}
+
+export default Show;

cypress/fixtures/pages-with-i18n/getStaticProps/with-revalidate.js

@@ -0,0 +1,32 @@
+import Link from "next/link";
+
+const Show = ({ show }) => (
+  <div>
+    <p>This page uses getStaticProps() to pre-fetch a TV show.</p>
+
+    <hr />
+
+    <h1>Show #{show.id}</h1>
+    <p>{show.name}</p>
+
+    <hr />
+
+    <Link href="/">
+      <a>Go back home</a>
+    </Link>
+  </div>
+);
+
+export async function getStaticProps(context) {
+  const res = await fetch(`https://api.tvmaze.com/shows/71`);
+  const data = await res.json();
+
+  return {
+    props: {
+      show: data,
+    },
+    revalidate: 1,
+  };
+}
+
+export default Show;