Apply PR code suggestions

Author: Vladimir Tkac

README.md

@@ -95,6 +95,17 @@ fastify.register(oauthPlugin, {
 })
 ```
 
+Additionally, you can customize the names of the cookies by setting the `redirectStateCookieName` and `verifierCookieName` options. 
+The default values for these cookies are `oauth2-code-verifier` for `verifierCookieName` and `oauth2-redirect-state` for `redirectStateCookieName`.
+
+```js
+fastify.register(oauthPlugin, {
+  ...,
+  redirectStateCookieName: 'custom-redirect-state',
+  verifierCookieName: 'custom-code-verifier'
+})
+```
+
 ### Preset configurations
 
 You can choose some default setup to assign to `auth` option.

index.js

@@ -28,7 +28,7 @@ function defaultCheckStateFunction (request, callback) {
   const state = request.query.state
   const stateCookie =
     request.cookies[
-      this.redirectStateCookieName || DEFAULT_REDIRECT_STATE_COOKIE_NAME
+      this.redirectStateCookieName
     ]
   if (stateCookie && state === stateCookie) {
     callback()
@@ -135,7 +135,9 @@ function fastifyOauth2 (fastify, options, next) {
       scope,
       generateStateFunction = defaultGenerateStateFunction,
       checkStateFunction = defaultCheckStateFunction.bind({
-        redirectStateCookieName: configured.redirectStateCookieName
+        redirectStateCookieName:
+          configured.redirectStateCookieName ||
+          DEFAULT_REDIRECT_STATE_COOKIE_NAME
       }),
       startRedirectPath,
       tags = [],