get token only after it expires are app starts

server.js

@@ -3,6 +3,9 @@ const app = express();
 const axios = require('axios');
 const querystring = require('querystring');
 
+let tokenExpirationDate = false;
+let bearerToken;
+
 const data = {
 	grant_type:'password',
 	username:process.env.REDDITUSR,
@@ -14,16 +17,20 @@ const auth = {
 }
 
 const getToken = async ()=>{
-	const response = await axios({
-		url:'https://www.reddit.com/api/v1/access_token',
-		method:'post',
-		auth:auth, 
-		data:querystring.stringify(data)
-	})
+	if(tokenExpirationDate === false || Date.now() > tokenExpirationDate){
+		const response = await axios({
+			url:'https://www.reddit.com/api/v1/access_token',
+			method:'post',
+			auth:auth, 
+			data:querystring.stringify(data)
+		})
+		bearerToken = response.data.access_token
+		tokenExpirationDate = Date.now()+(response.data.expires_in*1000)
+	}
 
 	const config = {
 		headers:{
-			Authorization: 'bearer '+response.data.access_token
+			Authorization: 'bearer '+ bearerToken
 		}
 	}
 	return config
@@ -48,6 +55,8 @@ const generate = async (req, res)=>{
 
 }
 
+getToken();
+
 app.get('/', generate)
 
 app.get('/:direction/:page', generate)