add sessionExpire option

example/test.ts

@@ -1,6 +1,6 @@
 import { Status } from "https://deno.land/std@0.186.0/http/http_status.ts";
 import prettyTime from "npm:pretty-time";
-import { HTTPServer } from "../mod.ts";
+import { HTTPServer, SessionExpire } from "../mod.ts";
 
 const JOKES = [
   "Why do Java developers often wear glasses? They can't C#.",
@@ -194,4 +194,5 @@ httpServer.listen({
   staticLocalDir: "/static",
   staticServePath: "/assets",
   sessionSecret: "SuperDuperSecret",
+  sessionExpire: SessionExpire.NEVER
 });

mod.ts

@@ -13,8 +13,13 @@ type HTTPServerOptions = {
   staticLocalDir?: string;
   staticServePath?: string;
   sessionSecret?: string;
+  sessionExpire?: SessionExpire | number;
 };
 
+export enum SessionExpire {
+  NEVER = 2147483647,
+}
+
 export enum HTTPMethod {
   GET = "GET",
   POST = "POST",
@@ -277,7 +282,9 @@ export class HTTPServer {
         sessionObject,
         this.settings?.sessionSecret,
       );
-      routeReply.cookie("session", encodedSession);
+      routeReply.cookie("session", encodedSession, {
+        maxAge: this.settings.sessionExpire ?? undefined,
+      });
     }
   }
 
@@ -433,9 +440,9 @@ export class RouteRequest {
         sessionCookie,
         httpServer.settings.sessionSecret,
       );
-      try{
+      try {
         this.session = JSON.parse(decodedSessionCookie);
-      }catch(_err){
+      } catch (_err) {
         // Ignore if sessionCookie is not in JSON format
       }
     }