clean code

apps/app/src/components/Page/PageView.tsx

@@ -137,7 +137,7 @@ export const PageView = (props: Props): JSX.Element => {
     const markdown = page.revision.body;
 
     const [marp, useSlide] = parseSlideFrontmatterInMarkdown(markdown);
-    const useMarp = enabledMarp && marp;
+    const useMarp = (enabledMarp ?? false) && marp;
 
     return (
       <>

apps/app/src/components/PageEditor/Preview.tsx

@@ -35,7 +35,7 @@ const Preview = (props: Props): JSX.Element => {
 
   const { data: enabledMarp } = useIsEnabledMarp();
   const [marp, useSlide] = parseSlideFrontmatterInMarkdown(markdown);
-  const useMarp = enabledMarp && marp;
+  const useMarp = (enabledMarp ?? false) && marp;
 
   return (
     <div

apps/app/src/components/ShareLinkPageView.tsx

@@ -90,7 +90,7 @@ export const ShareLinkPageView = (props: Props): JSX.Element => {
     const markdown = page.revision.body;
 
     const [marp, useSlide] = parseSlideFrontmatterInMarkdown(markdown);
-    const useMarp = enabledMarp && marp;
+    const useMarp = (enabledMarp ?? false) && marp;
 
     return (
       <>