feat: Dual ESM+CJS build

BREAKING CHANGE: Default export has been replaced with a named import:

```ts
import { checkEnv } from '@47ng/check-env'
```

.npmignore

@@ -7,4 +7,4 @@ src/
 tsconfig.json
 yarn-error.log
 *.test.*
-dist/demo*
+output.png

README.md

@@ -23,7 +23,7 @@ yarn add @47ng/check-env
 ## Usage
 
 ```js
-import checkEnv from '@47ng/check-env'
+import { checkEnv } from '@47ng/check-env'
 
 checkEnv({
   // Will log an error and throw if any of these are missing:

package.json

@@ -1,8 +1,6 @@
 {
   "name": "@47ng/check-env",
   "version": "0.0.0-semantically-released",
-  "main": "dist/index.js",
-  "types": "dist/index.d.ts",
   "description": "Check that the critical environment variables are set",
   "license": "MIT",
   "author": {
@@ -21,12 +19,25 @@
   "publishConfig": {
     "access": "public"
   },
+  "main": "./dist/index.cjs",
+  "module": "./dist/index.mjs",
+  "types": "./dist/index.d.ts",
+  "type": "module",
+  "sideEffects": false,
+  "exports": {
+    ".": {
+      "require": "./dist/index.cjs",
+      "import": "./dist/index.mjs",
+      "types": "./dist/index.d.ts"
+    }
+  },
   "scripts": {
     "test": "jest --coverage",
     "test:watch": "jest --verbose --watch",
-    "build:clean": "rm -rf ./dist",
-    "build:ts": "tsc",
-    "build": "run-s build:clean build:ts",
+    "prebuild": "rm -rf ./dist",
+    "build:typecheck": "tsc",
+    "build:transpile": "unbuild",
+    "build": "run-p build:*",
     "ci": "run-s test build",
     "prepare": "husky install"
   },
@@ -40,7 +51,8 @@
     "npm-run-all": "^4.1.5",
     "ts-jest": "^29.0.3",
     "ts-node": "^10.9.1",
-    "typescript": "^4.8.4"
+    "typescript": "^4.8.4",
+    "unbuild": "^0.9.4"
   },
   "jest": {
     "verbose": true,

src/check-env.test.ts

@@ -1,4 +1,5 @@
-import checkEnv, {
+import {
+  checkEnv,
   CheckEnvInput,
   MissingEnvironmentVariableError,
   UnsafeEnvironmentVariableError

src/demo.ts

@@ -1,4 +1,4 @@
-import checkEnv from './index'
+import { checkEnv } from './index'
 
 const env = {
   NODE_ENV: 'production',

src/index.ts

@@ -46,7 +46,7 @@ export class UnsafeEnvironmentVariableError extends Error {
 
 // --
 
-const checkEnv = (
+export const checkEnv = (
   {
     required,
     unsafe,
@@ -111,5 +111,3 @@ const checkEnv = (
     unsafe: unsafeProd
   }
 }
-
-export default checkEnv

tsconfig.json

@@ -4,10 +4,10 @@
     "target": "es2018",
     "lib": ["DOM"],
     "module": "commonjs",
-    "declaration": true,
-    "outDir": "./dist",
     "rootDir": "./src",
+    "moduleResolution": "node",
     "esModuleInterop": true,
+    "noEmit": true,
 
     // Strict Type-Checking Options
     "strict": true,