fix: default value of --wait-for option (#1730)

Author: kermanx

docs/guide/exporting.md

@@ -171,15 +171,15 @@ Some parts of your slides may require a longer time to render. You can use the `
 $ slidev export --wait 10000
 ```
 
-There is also a `--wait-until` option to wait for a state before exporting each slide:
+There is also a `--wait-until` option to wait for a state before exporting each slide. If you keep encountering timeout issues, you can try setting this option:
 
 ```bash
 $ slidev export --wait-until none
 ```
 
 Possible values:
 
-- `'networkidle'` - (_default_) consider operation to be finished when there are no network connections for at least `500` ms. Don't use this method for testing, rely on web assertions to assess readiness instead.
+- `'networkidle'` - (_default_) consider operation to be finished when there are no network connections for at least `500` ms. This is the safest, but may cause timeouts.
 - `'domcontentloaded'` - consider operation to be finished when the `DOMContentLoaded` event is fired.
 - `'load'` - consider operation to be finished when the `load` event is fired.
 - `'none'` - do not wait for any event.

packages/slidev/node/commands/export.ts

@@ -597,7 +597,7 @@ export function getExportOptions(args: ExportArgs, options: ResolvedSlidevOption
     format: (format || 'pdf') as 'pdf' | 'png' | 'pptx' | 'md',
     timeout: timeout ?? 30000,
     wait: wait ?? 0,
-    waitUntil: waitUntil === 'none' ? undefined : waitUntil as 'networkidle' | 'load' | 'domcontentloaded',
+    waitUntil: waitUntil === 'none' ? undefined : (waitUntil ?? 'networkidle') as 'networkidle' | 'load' | 'domcontentloaded',
     dark: dark || options.data.config.colorSchema === 'dark',
     routerMode: options.data.config.routerMode,
     width: options.data.config.canvasWidth,