enhance err mssg

server/server.tsx

@@ -8,12 +8,19 @@ import { EirikLd } from '../src/ld';
 import { ContactFormData } from '../src/types';
 import { Resend } from 'resend';
 
+const missingEnvVars:Array<string> = [];
+for (const envVar of ['RESEND_API_KEY','RESEND_TO_EMAIL','RESEND_FROM_EMAIL']){
+  if (!process.env[envVar]){
+    missingEnvVars.push(envVar);
+  }
+}
+if (missingEnvVars.length){
+  throw new Error(`Missing env vars [ ${missingEnvVars.join(', ')} ]`);
+}
+
 const resend = new Resend(process.env['RESEND_API_KEY']);
 const toMail = process.env['RESEND_TO_EMAIL'];
 const fromMail = process.env['RESEND_FROM_EMAIL'];
-if (!toMail||!fromMail){
-  throw new Error("Incomplete mail config");
-}
 
 const PORT = process.env.PORT || 3000;
 const app = express();