fix: no default value for object props

Author: sxzz

src/Repl.vue

@@ -52,18 +52,8 @@ const props = withDefaults(defineProps<Props>(), {
   clearConsole: true,
   layoutReverse: false,
   ssr: false,
-  previewOptions: () => ({
-    headHTML: '',
-    bodyHTML: '',
-    placeholderHTML: '',
-    customCode: {
-      importCode: '',
-      useCode: '',
-    },
-    showRuntimeError: true,
-    showRuntimeWarning: true,
-  }),
   layout: 'horizontal',
+  previewOptions: () => ({}),
   editorOptions: () => ({}),
 })
 

src/output/Preview.vue

@@ -290,9 +290,9 @@ defineExpose({ reload, container })
     class="iframe-container"
     :class="{ [theme]: previewTheme }"
   />
-  <Message :err="runtimeError && previewOptions?.showRuntimeError" />
+  <Message :err="runtimeError && (previewOptions?.showRuntimeError ?? true)" />
   <Message
-    v-if="!runtimeError && previewOptions?.showRuntimeWarning"
+    v-if="!runtimeError && (previewOptions?.showRuntimeWarning ?? true)"
     :warn="runtimeWarning"
   />
 </template>