feat: add ESM-compatibility (#11)

package.json

@@ -3,13 +3,21 @@
   "version": "1.3.0",
   "description": "Type-safe implementation of invariant with positionals.",
   "main": "lib/index.js",
+  "module": "lib/index.mjs",
   "typings": "lib/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./lib/index.d.ts",
+      "require": "./lib/index.js",
+      "default": "./lib/index.mjs"
+    }
+  },
   "author": "Artem Zakharchenko",
   "license": "MIT",
   "scripts": {
     "test": "jest",
     "clean": "rimraf ./lib",
-    "build": "yarn clean && tsc",
+    "build": "yarn clean && tsup",
     "prepublishOnly": "yarn test && yarn build",
     "release": "release publish"
   },
@@ -29,6 +37,7 @@
     "rimraf": "^3.0.2",
     "ts-jest": "^27.0.3",
     "ts-node": "^10.0.0",
+    "tsup": "^6.2.3",
     "typescript": "^4.3.4"
   },
   "repository": {

tsup.config.ts

@@ -0,0 +1,14 @@
+import { defineConfig } from 'tsup'
+
+export default defineConfig([
+  {
+    name: 'main',
+    entry: ['./src/index.ts'],
+    outDir: './lib',
+    format: ['esm', 'cjs'],
+    sourcemap: true,
+    clean: true,
+    bundle: true,
+    dts: true,
+  },
+])