feat: add warning for when node polyfill is used in non-node environments (#90)

Author: pi0

src/_utils.ts

@@ -0,0 +1,10 @@
+export function checkNodeEnvironment() {
+  if (
+    !globalThis.process?.versions?.node &&
+    !globalThis.process?.env.DISABLE_NODE_FETCH_NATIVE_WARN
+  ) {
+    throw new Error(
+      "Node.js compatible build of `node-fetch-native` is being used in a non-Node.js environment. Please make sure you are using proper export conditions or report this issue to https://github.com/unjs/node-fetch-native. You can set `process.env.DISABLE_NODE_FETCH_NATIVE_WARN` to disable this warning.",
+    );
+  }
+}

src/node.ts

@@ -1,8 +1,11 @@
 import _fetch from "node-fetch";
+import { checkNodeEnvironment } from "./_utils";
 
 export { Blob, File, FormData, Headers, Request, Response } from "node-fetch";
 export { default as AbortController } from "abort-controller";
 
+checkNodeEnvironment();
+
 export const fetch = _fetch;
 export default fetch;
 

src/polyfill.ts

@@ -9,6 +9,10 @@ import _fetch, {
 
 import _AbortController from "abort-controller";
 
+import { checkNodeEnvironment } from "./_utils";
+
+checkNodeEnvironment();
+
 function polyfill(name: string, impl: any) {
   if (!(name in globalThis)) {
     try {