fix(env): use APP_ENV instead of NODE_ENV if present

src/provider.ts

@@ -3,7 +3,10 @@ import minimist from 'minimist';
 import { environmentPatterns } from './common';
 
 export function convenience() {
-  let nodeEnv = process.env.NODE_ENV || 'development';
+  // NextJS philosophy is don't use non-standard NODE_ENV values, and this seems
+  // reasonable. APP_ENV includes staging, which is not a NODE_ENV value.
+  // So we will try to pick the best one we can find
+  let nodeEnv = process.env.APP_ENV || process.env.NODE_ENV || 'development';
   const env: Record<string, string | boolean> = {};
 
   // Normalize env and set convenience values.
@@ -27,7 +30,7 @@ export function environmentVariables(ignore: string[]) {
   // process.env is not a normal object, so we
   // need to map values.
   for (const env of Object.keys(process.env)) {
-    // env:env is decided by process.env.NODE_ENV.
+    // env:env is decided by process.env.APP_ENV or process.env.NODE_ENV.
     // Not allowing process.env.env to override the env:env value.
     if (ignore.indexOf(env) < 0) {
       result[env] = process.env[env];