fix: build only-esm lib to cjs

package.json

@@ -48,7 +48,9 @@
     "debug": "^4.3.4",
     "esbuild": "^0.17.12",
     "fs-extra": "^11.1.1",
-    "tiny-glob": "^0.2.9"
+    "on-change": "^4.0.2",
+    "tiny-glob": "^0.2.9",
+    "watcher": "^2.2.2"
   },
   "devDependencies": {
     "@minko-fe/eslint-config": "^1.2.31",
@@ -61,11 +63,9 @@
     "conventional-changelog-cli": "^2.2.2",
     "eslint": "^8.36.0",
     "mock-fs": "^5.2.0",
-    "on-change": "^4.0.2",
     "tsup": "^6.7.0",
     "typescript": "^5.0.2",
     "vite": "^4.2.1",
-    "vitest": "^0.29.7",
-    "watcher": "^2.2.2"
+    "vitest": "^0.29.7"
   }
 }

tsup.config.ts

@@ -1,17 +1,27 @@
+import type { Options } from 'tsup'
 import { defineConfig } from 'tsup'
 
-export const tsup = defineConfig((option) => ({
-  entry: ['src/index.ts'],
-  dts: true,
-  clean: false,
-  format: ['cjs', 'esm'],
-  minify: false,
-  platform: 'node',
-  sourcemap: !!option.watch,
-  tsconfig: option.watch ? './tsconfig.dev.json' : './tsconfig.json',
-  esbuildOptions(opts, { format }) {
-    if (format === 'esm') {
-      opts.external = ['watcher', 'on-change']
-    }
+const commonConfig = (option: Options): Options => {
+  return {
+    clean: false,
+    minify: false,
+    platform: 'node',
+    sourcemap: !!option.watch,
+    tsconfig: option.watch ? './tsconfig.dev.json' : './tsconfig.json',
+  }
+}
+
+export const tsup = defineConfig((option) => [
+  {
+    entry: ['src/index.ts'],
+    dts: true,
+    format: ['esm'],
+    ...commonConfig(option),
+  },
+  {
+    entry: ['src/index.ts'],
+    noExternal: ['on-change', 'watcher'],
+    format: ['cjs'],
+    ...commonConfig(option),
   },
-}))
+])