fix: use worker thread to run rollup again

src/index.ts

@@ -1,5 +1,6 @@
 import fs from 'fs'
 import { dirname, join, extname } from 'path'
+import { Worker } from 'worker_threads'
 import colors from 'chalk'
 import type { InputOption } from 'rollup'
 import { transform as transformToEs5 } from 'buble'
@@ -338,8 +339,6 @@ export async function build(_options: Options) {
 
   let existingOnSuccess: ChildProcess | undefined
 
-  let esbuildRunning: Promise<void> | undefined
-
   const buildAll = async () => {
     if (existingOnSuccess) existingOnSuccess.kill()
 
@@ -375,7 +374,7 @@ export async function build(_options: Options) {
     })
     watcher.on('all', async (type, file) => {
       console.log(makeLabel('CLI', 'info'), `Change detected: ${type} ${file}`)
-      esbuildRunning = buildAll().catch(handleError)
+      await buildAll().catch(handleError)
     })
   }
 
@@ -391,7 +390,20 @@ export async function build(_options: Options) {
       throw new Error(`You need to install "typescript" in your project`)
     }
 
-    const { startRollup } = await import('./rollup')
-    await startRollup(options, () => esbuildRunning)
+    const isDev = __filename.endsWith('index.ts')
+    const worker = new Worker(
+      join(__dirname, isDev ? './rollup.dev.js' : './rollup.js')
+    )
+    worker.postMessage({
+      options: {
+        ...options, // functions cannot be cloned
+        esbuildPlugins: undefined,
+      },
+    })
+    worker.on('message', (data) => {
+      if (data === 'has-error') {
+        process.exitCode = 1
+      }
+    })
   }
 }

src/rollup.dev.js

@@ -0,0 +1 @@
+import './rollup'

src/rollup.ts

@@ -1,3 +1,4 @@
+import { parentPort } from 'worker_threads'
 import { InputOptions, OutputOptions, Plugin } from 'rollup'
 import { makeLabel, NormalizedOptions } from './'
 import dtsPlugin from 'rollup-plugin-dts'
@@ -117,26 +118,15 @@ async function runRollup(options: RollupConfig) {
   }
 }
 
-async function watchRollup(
-  options: {
-    inputConfig: InputOptions
-    outputConfig: OutputOptions
-  },
-  waitForEsbuild: WaitForEsbuild
-) {
+async function watchRollup(options: {
+  inputConfig: InputOptions
+  outputConfig: OutputOptions
+}) {
   const { watch } = await import('rollup')
 
   watch({
     ...options.inputConfig,
-    plugins: [
-      {
-        name: 'wait-for-esbuild',
-        async buildStart() {
-          await waitForEsbuild()
-        },
-      },
-      ...(options.inputConfig.plugins || []),
-    ],
+    plugins: options.inputConfig.plugins,
     output: options.outputConfig,
   }).on('event', async (event) => {
     if (event.code === 'START') {
@@ -153,16 +143,16 @@ async function watchRollup(
   })
 }
 
-type WaitForEsbuild = () => undefined | Promise<void>
-
-export const startRollup = async (
-  options: NormalizedOptions,
-  waitForEsbuild: WaitForEsbuild
-) => {
+const startRollup = async (options: NormalizedOptions) => {
   const config = await getRollupConfig(options)
   if (options.watch) {
-    watchRollup(config, waitForEsbuild)
+    watchRollup(config)
   } else {
     await runRollup(config)
+    parentPort?.close()
   }
 }
+
+parentPort?.on('message', (data) => {
+  startRollup(data.options)
+})