add frontMatter.sidebarTitle only if frontMatter.title is empty (#2656)

* add `frontMatter.sidebarTitle` only if `frontMatter.title` is empty

* fallback.display '*'

Author: Dimitri POSTOLOV

.changeset/fast-readers-sleep.md

@@ -0,0 +1,5 @@
+---
+'nextra': patch
+---
+
+add `frontMatter.sidebarTitle` only if `frontMatter.title` is empty

docs/next-env.d.ts

@@ -1,5 +1,6 @@
 /// <reference types="next" />
 /// <reference types="next/image-types/global" />
+/// <reference types="next/navigation-types/compat/navigation" />
 
 // NOTE: This file should not be edited
 // see https://nextjs.org/docs/basic-features/typescript for more information.

packages/nextra/src/client/normalize-pages.ts

@@ -42,7 +42,7 @@ function extendMeta(
   return {
     ...fallback,
     ..._meta,
-    display: metadata.display || _meta.display,
+    display: metadata.display || _meta.display || fallback.display,
     theme
   }
 }

packages/nextra/src/server/page-map.ts

@@ -125,16 +125,15 @@ async function collectFiles({
           // } else {
           const content = await fs.readFile(filePath, 'utf8')
           const { data } = grayMatter(content)
-          const frontMatter = {
-            sidebarTitle: pageTitleFromFilename(name),
-            ...data
+          if (!data.title) {
+            data.sidebarTitle = pageTitleFromFilename(name)
           }
           // }
 
           return {
             name,
             route: fileRoute,
-            frontMatter
+            frontMatter: data
           }
         }