fix preview fonts and dev-only routes

Author: aurorascharff

src/app/api/md/[...path]/route.ts

@@ -9,7 +9,7 @@ import fs from 'fs';
 import path from 'path';
 import {NextResponse} from 'next/server';
 import {cacheLife} from 'next/cache';
-import {collectAllContentPaths} from 'lib/collectPaths';
+import {collectAllContentPaths, isContentPageAvailable} from 'lib/collectPaths';
 
 const FOOTER = `
 ---
@@ -39,6 +39,7 @@ async function readContentMarkdown(
   'use cache';
   cacheLife('max');
   if (!pathSegments || pathSegments.length === 0) return null;
+  if (!isContentPageAvailable(pathSegments)) return null;
 
   const filePath = pathSegments.join('/');
   // Block /index.md URLs - use /foo.md instead of /foo/index.md

src/app/layout.tsx

@@ -189,7 +189,7 @@ export default function RootLayout({children}: {children: React.ReactNode}) {
           <link
             key={file}
             rel="preload"
-            href={`https://react.dev/fonts/${file}`}
+            href={`/fonts/${file}`}
             as="font"
             type="font/woff2"
             crossOrigin="anonymous"

src/lib/collectPaths.ts

@@ -17,6 +17,13 @@ const stat = promisify(fs.stat);
 const ROOT = path.join(process.cwd(), 'src/content');
 const DEV_ONLY_PAGES = new Set(['learn/rsc-sandbox-test']);
 
+export function isContentPageAvailable(segments: string[]): boolean {
+  return (
+    process.env.NODE_ENV !== 'production' ||
+    !DEV_ONLY_PAGES.has(segments.join('/'))
+  );
+}
+
 async function getFiles(dir: string, base: string): Promise<string[]> {
   const subdirs = await readdir(dir);
   const files = await Promise.all(
@@ -54,10 +61,7 @@ export async function collectSectionPaths(
   const files = await getFiles(dir, dir);
   return files
     .map((file) => getSegments(file))
-    .filter((segments) => {
-      if (process.env.NODE_ENV !== 'production') return true;
-      return !DEV_ONLY_PAGES.has([section, ...segments].join('/'));
-    });
+    .filter((segments) => isContentPageAvailable([section, ...segments]));
 }
 
 /**
@@ -76,6 +80,7 @@ export async function collectAllContentPaths(): Promise<string[][]> {
       // Drop the root `index.md` (-> []); `/index.md` isn't a served URL and an
       // empty catch-all param can't be prerendered.
       .filter((segments) => segments.length > 0)
+      .filter(isContentPageAvailable)
   );
 }
 

src/lib/readMarkdownPage.ts

@@ -9,6 +9,7 @@ import 'server-only';
 import fs from 'fs/promises';
 import path from 'path';
 import {cacheLife} from 'next/cache';
+import {isContentPageAvailable} from './collectPaths';
 import compileMDX from 'utils/compileMDX';
 import type {CompiledMDX} from 'utils/compileMDX';
 
@@ -33,6 +34,7 @@ export async function readMarkdownPage(
 ): Promise<PageData | null> {
   'use cache';
   cacheLife('max');
+  if (!isContentPageAvailable(segments)) return null;
   const routePath = segments.join('/') || 'index';
   let mdx: string | null = null;
   for (const candidate of [