[v3] specify default language for code blocks (#3108)

[v3] specify the default language as plaintext for code blocks

Co-authored-by: Dimitri POSTOLOV <dmytropostolov@gmail.com>

Author: 87xie

.changeset/chilly-shoes-marry.md

@@ -0,0 +1,7 @@
+---
+'nextra-theme-blog': patch
+'nextra-theme-docs': patch
+'nextra': patch
+---
+
+To ensure consistent horizontal padding, set the default language as plaintext for code blocks. This prevents any loss of formatting for code blocks without a specified language.

examples/blog/pages/posts/code-blocks.mdx

@@ -42,6 +42,16 @@ object Hello {
 hello world
 ```
 
+## Test with code block default language
+
+```
+const links = [
+  { href: '/settings', label: 'Settings' },
+  { href: '/support', label: 'Support' },
+  { href: '/license', label: 'License' },
+]
+```
+
 ## Test link in code
 
 Link to [`google`](https://google.com)

packages/nextra/src/server/rehype-plugins/rehype.ts

@@ -27,6 +27,9 @@ export const DEFAULT_REHYPE_PRETTY_CODE_OPTIONS: RehypePrettyCodeOptions = {
     light: 'github-light',
     dark: 'github-dark'
   },
+  defaultLang: {
+    block: 'plaintext'
+  },
   getHighlighter(opts) {
     return getHighlighter({
       ...opts,