Attempt to fix ESM (#89)

esbuild.esm.mjs

@@ -0,0 +1,11 @@
+import { build } from 'esbuild';
+
+await build({
+  entryPoints: ['src/index.ts'],
+  bundle: true,
+  platform: 'node',
+  format: 'esm',
+  target: ['es2022'],
+  outdir: './lib-esm',
+  outExtension: { '.js': '.mjs' },
+});

esbuild.mjs

@@ -0,0 +1,10 @@
+import { build } from 'esbuild';
+
+await build({
+  entryPoints: ['src/index.ts'],
+  bundle: true,
+  platform: 'node',
+  format: 'cjs',
+  target: ['es2022'],
+  outdir: './lib-commonjs',
+});

package.json

@@ -25,17 +25,23 @@
   },
   "license": "MIT",
   "sideEffects": false,
+  "exports": {
+    ".": {
+      "import": "./lib-esm/index.mjs",
+      "require": "./lib-commonjs/index.js",
+      "types": "./lib-types/index.d.ts"
+    }
+  },
   "main": "./lib-commonjs/index.js",
-  "module": "./lib-es2015/index.js",
+  "module": "./lib-esm/index.mjs",
   "types": "./lib-types/index.d.ts",
   "files": [
     "lib*/**/*.d.ts",
-    "lib*/**/*.js",
-    "lib*/**/*.js.map",
+    "lib*/**/*.{js,mjs}{,.map}",
     "lib*/**/*.json"
   ],
   "scripts": {
-    "build": "skuba build-package",
+    "build": "node esbuild.mjs && node esbuild.esm.mjs && tsc --allowJS false --declaration --emitDeclarationOnly --outDir lib-types --project tsconfig.build.json",
     "format": "skuba format",
     "lint": "skuba lint",
     "prepare": "pnpm build",