feat: polyfill support

README.md

@@ -23,6 +23,7 @@ A redistribution of [node-fetch v3](https://github.com/node-fetch/node-fetch) fo
 
 ✅ Use native version if imported without `node` condition using [conditional exports](https://nodejs.org/api/packages.html#packages_conditional_exports) with **zero bundle overhead**
 
+✅ Polyfill support for Node.js
 
 ## Usage
 
@@ -49,7 +50,7 @@ import fetch from 'node-fetch-native'
 const fetch = require('node-fetch-native')
 ```
 
-Other exports:
+More named exports:
 
 ```js
 // ESM
@@ -59,6 +60,22 @@ import { fetch, Blob, FormData, Headers, Request, Response } from 'node-fetch-na
 const { fetch, Blob, FormData, Headers, Request, Response } = require('node-fetch-native')
 ```
 
+## Polyfill support
+
+Using the polyfill method, we can once ensure global fetch is available in the environment and all files. Natives are always preferred.
+
+**Note:** I don't recommand this if you are authoring a library! Please prefer explicit methods.
+
+```js
+// ESM
+import 'node-fetch-native/polyfill'
+
+// CJS
+require('node-fetch-native/polyfill')
+
+// You can now use fetch() without any import!
+```
+
 ## Alias to `node-fetch`
 
 Using this method, you can ensure all project dependencies and usages of `node-fetch` can benefit from improved `node-fetch-native` and won't conflict between `node-fetch@2` and `node-fetch@3`.

build.config.ts

@@ -8,6 +8,7 @@ export default defineBuildConfig({
   },
   entries: [
     'src/index',
-    'src/native'
+    'src/native',
+    'src/polyfill'
   ]
 })

package.json

@@ -1,10 +1,9 @@
 {
   "name": "node-fetch-native",
   "version": "0.1.1",
-  "description": "",
+  "description": "A better redistribution of `node-fetch`",
   "repository": "unjs/node-fetch-native",
   "license": "MIT",
-  "sideEffects": false,
   "type": "module",
   "exports": {
     ".": {
@@ -14,6 +13,13 @@
       },
       "import": "./dist/native.mjs"
     },
+    "./polyfill": {
+      "node": {
+        "require": "./dist/polyfill.cjs",
+        "import": "./dist/polyfill.mjs"
+      },
+      "import": "./lib/empty.mjs"
+    },
     "./src/index.js": {
       "import": "./dist/index.mjs"
     }

src/polyfill.ts

@@ -0,0 +1,17 @@
+import _fetch, {
+  Blob as _Blob,
+  File as _File,
+  FormData as _FormData,
+  Headers as _Headers,
+  Request as _Request,
+  Response as _Response
+} from 'node-fetch'
+
+globalThis.fetch = globalThis.fetch || _fetch as unknown as typeof globalThis.fetch
+
+globalThis.Blob = globalThis.Blob || _Blob
+globalThis.File = globalThis.File || _File
+globalThis.FormData = globalThis.FormData || _FormData
+globalThis.Headers = globalThis.Headers || _Headers
+globalThis.Request = globalThis.Request || _Request as unknown as typeof globalThis.Request
+globalThis.Response = globalThis.Response || _Response as unknown as typeof globalThis.Response