feat: add --publicDir [dir] flag

docs/README.md

@@ -522,6 +522,12 @@ export default defineConfig({
 - When building the cjs bundle, it will compile `import.meta.url` as `typeof document === "undefined" ? new URL("file:" + __filename).href : document.currentScript && document.currentScript.src || new URL("main.js", document.baseURI).href`
 - When building the esm bundle, it will compile `__dirname` as `path.dirname(fileURLToPath(import.meta.url))`
 
+### Copy files to output directory
+
+Use `--publicDir` flag to copy files inside `./public` folder to the output directory.
+
+You can also specify a custom directory using `--publicDir another-directory`.
+
 ## Troubleshooting
 
 ### error: No matching export in "xxx.ts" for import "xxx"

src/cli-main.ts

@@ -90,6 +90,7 @@ export async function main(options: Options = {}) {
       '--treeshake [strategy]',
       'Using Rollup for treeshaking instead, "recommended" or "smallest" or "safest"'
     )
+    .option('--publicDir [dir]', 'Copy public directory to output directory')
     .action(async (files: string[], flags) => {
       const { build } = await import('.')
       Object.assign(options, {

src/fs.ts

@@ -9,3 +9,22 @@ export const outputFile = async (
   await fs.promises.mkdir(path.dirname(filepath), { recursive: true })
   await fs.promises.writeFile(filepath, data, options)
 }
+
+export function copyDirSync(srcDir: string, destDir: string): void {
+  if (!fs.existsSync(srcDir)) return
+
+  fs.mkdirSync(destDir, { recursive: true })
+  for (const file of fs.readdirSync(srcDir)) {
+    const srcFile = path.resolve(srcDir, file)
+    if (srcFile === destDir) {
+      continue
+    }
+    const destFile = path.resolve(destDir, file)
+    const stat = fs.statSync(srcFile)
+    if (stat.isDirectory()) {
+      copyDirSync(srcFile, destFile)
+    } else {
+      fs.copyFileSync(srcFile, destFile)
+    }
+  }
+}

src/index.ts

@@ -19,6 +19,7 @@ import { PluginContainer } from './plugin'
 import { es5 } from './plugins/es5'
 import { sizeReporter } from './plugins/size-reporter'
 import { treeShakingPlugin } from './plugins/tree-shaking'
+import { copyPublicDir, isInPublicDir } from './lib/public-dir'
 
 export type { Format, Options, NormalizedOptions }
 
@@ -122,7 +123,7 @@ const normalizeOptions = async (
   if (!options.target) {
     options.target = 'node14'
   }
-  
+
   return options as NormalizedOptions
 }
 
@@ -328,6 +329,16 @@ export async function build(_options: Options) {
               })
               watcher.on('all', async (type, file) => {
                 file = slash(file)
+
+                if (
+                  options.publicDir &&
+                  isInPublicDir(options.publicDir, file)
+                ) {
+                  logger.info('CLI', `Change in public dir: ${file}`)
+                  copyPublicDir(options.publicDir, options.outDir)
+                  return
+                }
+
                 // By default we only rebuild when imported files change
                 // If you specify custom `watch`, a string or multiple strings
                 // We rebuild when those files change
@@ -355,6 +366,7 @@ export async function build(_options: Options) {
             logger.info('CLI', `Target: ${options.target}`)
 
             await buildAll()
+            copyPublicDir(options.publicDir, options.outDir)
 
             startWatcher()
           }

src/lib/public-dir.ts

@@ -0,0 +1,22 @@
+import path from 'path'
+import { copyDirSync } from '../fs'
+import { slash } from '../utils'
+
+export const copyPublicDir = (
+  publicDir: string | boolean | undefined,
+  outDir: string
+) => {
+  if (!publicDir) return
+  copyDirSync(path.resolve(publicDir === true ? 'public' : publicDir), outDir)
+}
+
+export const isInPublicDir = (
+  publicDir: string | boolean | undefined,
+  filePath: string
+) => {
+  if (!publicDir) return false
+  const publicPath = slash(
+    path.resolve(publicDir === true ? 'public' : publicDir)
+  )
+  return slash(path.resolve(filePath)).startsWith(`${publicPath}/`)
+}

src/options.ts

@@ -181,6 +181,10 @@ export type Options = {
    * This can result in smaller bundle size
    */
   treeshake?: TreeshakingStrategy
+  /**
+   * Copy the files inside `publicDir` to output directory
+   */
+  publicDir?: string | boolean
 }
 
 export type NormalizedOptions = Omit<