fix: fix line higlighting for empty lines

src/node/markdown/plugins/highlight.ts

@@ -136,11 +136,17 @@ export async function highlight(
       return s
     }
 
+    const fillEmptyHighlightedLine = (s: string) => {
+      return s.replace(
+        /(<span class="line highlighted">)(<\/span>)/g,
+        '$1<wbr>$2'
+      )
+    }
+
     str = removeMustache(str)
 
     const codeToHtml = (theme: IThemeRegistration) => {
-      return cleanup(
+      const res =
-        restoreMustache(
         lang === 'ansi'
           ? highlighter.ansiToHtml(str, {
               lineOptions,
@@ -151,8 +157,7 @@ export async function highlight(
               lineOptions,
               theme: getThemeName(theme)
             })
-        )
+      return fillEmptyHighlightedLine(cleanup(restoreMustache(res)))
-      )
     }
 
     if (hasSingleTheme) return codeToHtml(theme)