feat: added cjs support via esbuild

.gitignore

@@ -21,3 +21,6 @@ node_modules
 # Code Coverage
 /.nyc_output/
 /coverage/
+
+# esbuild
+dist

cjs-wrapper.cjs

@@ -0,0 +1,2 @@
+// <https://github.com/evanw/esbuild/issues/532#issuecomment-1019392638>
+module.exports = require('./dist/multer.cjs').default

package.json

@@ -7,19 +7,6 @@
     "Jaret Pfluger <https://github.com/jpfluger>",
     "Linus Unnebäck <linus@folkdatorn.se>"
   ],
-  "license": "MIT",
-  "repository": "expressjs/multer",
-  "type": "module",
-  "exports": "./index.js",
-  "keywords": [
-    "form",
-    "post",
-    "multipart",
-    "form-data",
-    "formdata",
-    "express",
-    "middleware"
-  ],
   "dependencies": {
     "@fastify/busboy": "^1.0.0",
     "append-field": "^2.0.0",
@@ -32,24 +19,49 @@
   },
   "devDependencies": {
     "c8": "^7.7.3",
+    "esbuild": "^0.15.15",
     "express": "^4.16.4",
     "form-data": "^4.0.0",
     "get-stream": "^6.0.1",
     "hasha": "^5.2.0",
     "mocha": "^9.0.3",
     "recursive-nullify": "^1.0.0",
+    "rimraf": "^3.0.2",
     "standard": "^16.0.3",
     "testdata-w3c-json-form": "^1.0.0"
   },
   "engines": {
     "node": "^12.20.0 || ^14.13.1 || >=16.0.0"
   },
+  "exports": {
+    "require": "./cjs-wrapper.cjs",
+    "import": "./index.js"
+  },
   "files": [
     "LICENSE",
     "index.js",
-    "lib/"
+    "cjs-wrapper.cjs",
+    "lib/",
+    "dist/"
   ],
+  "keywords": [
+    "express",
+    "form",
+    "form-data",
+    "formdata",
+    "middleware",
+    "multipart",
+    "post"
+  ],
+  "license": "MIT",
+  "type": "module",
+  "main": "cjs-wrapper.cjs",
+  "module": "./index.js",
+  "repository": "expressjs/multer",
   "scripts": {
-    "test": "standard && c8 --check-coverage --statements 100 mocha"
+    "lint": "standard",
+    "build": "rimraf dist && esbuild index.js --bundle --platform=node --charset=utf8 --minify --outfile=dist/multer.cjs",
+    "pretest": "npm run lint && npm run build",
+    "test": "c8 --check-coverage --statements 100 mocha"
   }
 }