feat(cli): export in dark mode, close #80

Author: antfu

packages/slidev/node/cli.ts

@@ -236,6 +236,11 @@ cli.command(
       type: 'string',
       describe: 'page ranges to export, for example "1,4-5,6"',
     })
+    .option('dark', {
+      default: false,
+      type: 'boolean',
+      describe: 'export as dark theme',
+    })
     .strict()
     .help(),
   async({
@@ -245,6 +250,7 @@ cli.command(
     format,
     timeout,
     range,
+    dark,
   }) => {
     output = output || `${path.basename(entry, '.md')}-export`
     process.env.NODE_ENV = 'production'
@@ -270,6 +276,7 @@ cli.command(
       format: format as any,
       output,
       timeout,
+      dark,
     })
     console.log(`${green('  ✓ ')}${dim('exported to ')}./${output}\n`)
     server.close()

packages/slidev/node/export.ts

@@ -14,6 +14,7 @@ export interface ExportOptions {
   format?: 'pdf' | 'png'
   output?: string
   timeout?: number
+  dark?: boolean
 }
 
 function createSlidevProgress() {
@@ -60,6 +61,7 @@ export async function exportSlides({
   output = 'slides',
   base = '/',
   timeout = 500,
+  dark = false,
 }: ExportOptions) {
   if (!packageExists('playwright-chromium'))
     throw new Error('The exporting for Slidev is powered by Playwright, please installed it via `npm i playwright-chromium`')
@@ -78,6 +80,9 @@ export async function exportSlides({
 
   async function go(no: number) {
     progress.update(no)
+
+    if (dark)
+      await page.emulateMedia({ colorScheme: 'dark' })
     await page.goto(`http://localhost:${port}${base}${no}?print`, {
       waitUntil: 'networkidle',
     })