enable replace token function

Author: steffenmllr

lib/context.js

@@ -47,6 +47,30 @@ async function refresh({ tokenEndpointParams } = {}) {
   return this.accessToken;
 }
 
+async function replace(refreshToken) {
+  let { config, req } = weakRef(this);
+
+  const client = await getClient(config);
+  const newTokenSet = await client.refresh(refreshToken);
+
+  // Update the session
+  const session = req[config.session.name];
+  Object.assign(session, {
+    id_token: newTokenSet.id_token,
+    access_token: newTokenSet.access_token,
+    refresh_token: newTokenSet.refresh_token || refreshToken,
+    token_type: newTokenSet.token_type,
+    expires_at: newTokenSet.expires_at,
+  });
+
+  // Delete the old token set
+  const cachedTokenSet = weakRef(session);
+
+  delete cachedTokenSet.value;
+
+  return this.accessToken;
+}
+
 function tokenSet() {
   const contextCache = weakRef(this);
   const session = contextCache.req[contextCache.config.session.name];
@@ -111,6 +135,7 @@ class RequestContext {
         expires_in,
         isExpired: isExpired.bind(this),
         refresh: refresh.bind(this),
+        replace: replace.bind(this),
       };
     } catch (err) {
       return undefined;