initial commit

apps/web/app/entry.server.tsx

@@ -0,0 +1,122 @@
+/* ============================================================================
+   SERVER ENTRY
+   ----------------------------------------------------------------------------
+   The stock React Router streaming entry plus two SHARP-ER additions:
+
+     - `Content-Language` is stamped from the URL's locale prefix, so the
+       header agrees with <html lang> that root.tsx renders. `Vary` is NOT set
+       globally: every page URL carries its own locale, so only the bare "/"
+       redirect varies on Accept-Language and it sets the header itself.
+     - `handleError` logs server errors without the noise of client aborts.
+   ========================================================================= */
+
+import { PassThrough } from "node:stream";
+
+import type { EntryContext, RouterContextProvider } from "react-router";
+import { createReadableStreamFromReadable } from "@react-router/node";
+import { ServerRouter } from "react-router";
+import { isbot } from "isbot";
+import type { RenderToPipeableStreamOptions } from "react-dom/server";
+import { renderToPipeableStream } from "react-dom/server";
+
+import { DEFAULT_LOCALE, getLocaleFromPathname } from "~/i18n/config";
+
+export const streamTimeout = 5_000;
+
+/** The locale a URL addresses, for the `Content-Language` response header. */
+function contentLanguage(request: Request): string {
+  try {
+    return getLocaleFromPathname(new URL(request.url).pathname) ?? DEFAULT_LOCALE;
+  } catch {
+    return DEFAULT_LOCALE;
+  }
+}
+
+export default function handleRequest(
+  request: Request,
+  responseStatusCode: number,
+  responseHeaders: Headers,
+  routerContext: EntryContext,
+  loadContext: RouterContextProvider,
+) {
+  // https://httpwg.org/specs/rfc9110.html#HEAD
+  if (request.method.toUpperCase() === "HEAD") {
+    return new Response(null, {
+      status: responseStatusCode,
+      headers: responseHeaders,
+    });
+  }
+
+  return new Promise((resolve, reject) => {
+    let shellRendered = false;
+    let userAgent = request.headers.get("user-agent");
+
+    // Ensure requests from bots and SPA Mode renders wait for all content to load before responding
+    // https://react.dev/reference/react-dom/server/renderToPipeableStream#waiting-for-all-content-to-load-for-crawlers-and-static-generation
+    let readyOption: keyof RenderToPipeableStreamOptions =
+      (userAgent && isbot(userAgent)) || routerContext.isSpaMode
+        ? "onAllReady"
+        : "onShellReady";
+
+    // Abort the rendering stream after the `streamTimeout` so it has time to
+    // flush down the rejected boundaries
+    let timeoutId: ReturnType<typeof setTimeout> | undefined = setTimeout(
+      () => abort(),
+      streamTimeout + 1000,
+    );
+
+    const { pipe, abort } = renderToPipeableStream(
+      <ServerRouter context={routerContext} url={request.url} />,
+      {
+        [readyOption]() {
+          shellRendered = true;
+          const body = new PassThrough({
+            final(callback) {
+              // Clear the timeout to prevent retaining the closure and memory leak
+              clearTimeout(timeoutId);
+              timeoutId = undefined;
+              callback();
+            },
+          });
+          const stream = createReadableStreamFromReadable(body);
+
+          responseHeaders.set("Content-Type", "text/html");
+          responseHeaders.set("Content-Language", contentLanguage(request));
+
+          pipe(body);
+
+          resolve(
+            new Response(stream, {
+              headers: responseHeaders,
+              status: responseStatusCode,
+            }),
+          );
+        },
+        onShellError(error: unknown) {
+          reject(error);
+        },
+        onError(error: unknown) {
+          responseStatusCode = 500;
+          // Log streaming rendering errors from inside the shell.  Don't log
+          // errors encountered during initial shell rendering since they'll
+          // reject and get logged in handleDocumentRequest.
+          if (shellRendered) {
+            console.error(error);
+          }
+        },
+      },
+    );
+  });
+}
+
+/**
+ * Central server-side error logging. A request the client walked away from is
+ * not an application error, so it is not logged as one.
+ */
+export function handleError(
+  error: unknown,
+  { request }: { request: Request },
+): void {
+  if (request.signal.aborted) return;
+  console.error(`[sharp-er] ${request.method} ${request.url}`, error);
+}