fix(proxy): update environment variable check order

Author: pi0

README.md

@@ -111,7 +111,7 @@ Node.js has no built-in support for HTTP Proxies for fetch (see [nodejs/undici#1
 
 This package bundles a compact and simple proxy-supported solution for both Node.js versions without native fetch using [HTTP Agent](https://github.com/TooTallNate/proxy-agents/tree/main/packages/proxy-agent) and versions with native fetch using [Undici Proxy Agent](https://undici.nodejs.org/#/docs/api/ProxyAgent).
 
-By default, `HTTP_PROXY`, `http_proxy`, `HTTPS_PROXY`, and `https_proxy` environment variables will be used for the proxy and if not any of them are set, the proxy will be disabled.
+By default, `https_proxy`, `http_proxy`, `HTTPS_PROXY`, and `HTTP_PROXY` environment variables will be checked and used (in order) for the proxy and if not any of them are set, the proxy will be disabled.
 
 > [!NOTE]
 > Using export conditions, this utility adds proxy support for Node.js and for other runtimes, it will simply return native fetch.

src/proxy.ts

@@ -11,10 +11,10 @@ import { fetch as _fetch } from "node-fetch-native";
 export function createProxy(opts: ProxyOptions = {}) {
   const uri =
     opts.url ||
-    process.env.HTTPS_PROXY ||
     process.env.https_proxy ||
-    process.env.HTTP_PROXY ||
-    process.env.http_proxy;
+    process.env.http_proxy ||
+    process.env.HTTPS_PROXY ||
+    process.env.HTTP_PROXY;
 
   if (!uri) {
     return {