Publish dual ESM and CJS modules

package.json

@@ -6,18 +6,26 @@
     "dist"
   ],
   "main": "dist/index.js",
+  "exports": {
+    "./package.json": "./package.json",
+    ".": {
+      "import": "./dist/index.js",
+      "default": "./dist/index.cjs"
+    }
+  },
   "scripts": {
-    "build": "tsc",
+    "build": "tsup",
     "check-format": "prettier --check .",
     "format": "prettier --write .",
     "check-types": "tsc --noEmit",
-    "check-exports": "attw --pack . --ignore-rules=cjs-resolves-to-esm",
-    "ci": "bun run build && bun run check-format && bun run check-exports"
+    "check-exports": "attw --pack .",
+    "ci": "bun run check-types && bun run check-format && bun run build && bun run check-exports"
   },
   "devDependencies": {
     "@arethetypeswrong/cli": "0.15.4",
     "@types/bun": "latest",
-    "prettier": "^3.3.3"
+    "prettier": "^3.3.3",
+    "tsup": "^8.2.4"
   },
   "peerDependencies": {
     "typescript": "^5.0.0",

tsconfig.json

@@ -8,6 +8,7 @@
     "jsx": "react-jsx",
     "allowJs": true,
     "outDir": "dist",
+    "noEmit": false,
 
     // Bundler mode
     "moduleResolution": "NodeNext",
@@ -22,11 +23,6 @@
     // Some stricter flags (disabled by default)
     "noUnusedLocals": true,
     "noUnusedParameters": true,
-    "noPropertyAccessFromIndexSignature": true,
-
-    // If building with Typescript
-    "rootDir": "src",
-    "sourceMap": true,
-    "declaration": true
+    "noPropertyAccessFromIndexSignature": true
   }
 }

tsup.config.ts

@@ -0,0 +1,9 @@
+import { defineConfig } from "tsup";
+
+export default defineConfig({
+  entryPoints: ["src/index.ts"],
+  format: ["cjs", "esm"],
+  dts: true,
+  outDir: "dist",
+  clean: true,
+});