feat: add readScope helper for extracting scopes from requests

Author: dhensby

index.d.ts

@@ -233,6 +233,11 @@ declare namespace OAuth2Server {
          * Additional supported grant types.
          */
         extendedGrantTypes?: Record<string, typeof AbstractGrantType>;
+
+        /**
+         * Helper function to extract scope string from the request.
+         */
+        readScope?: (request: Request) => string[] | null;
     }
 
     interface AssertionCredential {

lib/grant-types/abstract-grant-type.js

@@ -25,6 +25,7 @@ class AbstractGrantType {
     this.model = options.model;
     this.refreshTokenLifetime = options.refreshTokenLifetime;
     this.alwaysIssueNewRefreshToken = options.alwaysIssueNewRefreshToken;
+    this.readScope = options.readScope ?? ((request) => parseScope(request.body.scope));
   }
 
   /**
@@ -73,7 +74,7 @@ class AbstractGrantType {
    * Get scope from the request body.
    */
   getScope (request) {
-    return parseScope(request.body.scope);
+    return this.readScope(request);
   }
 
   /**

lib/handlers/token-handler.js

@@ -61,6 +61,7 @@ class TokenHandler {
     this.allowExtendedTokenAttributes = options.allowExtendedTokenAttributes;
     this.requireClientAuthentication = options.requireClientAuthentication || {};
     this.alwaysIssueNewRefreshToken = options.alwaysIssueNewRefreshToken !== false;
+    this.readScope = options.readScope;
   }
 
   /**
@@ -247,7 +248,8 @@ class TokenHandler {
       accessTokenLifetime: accessTokenLifetime,
       model: this.model,
       refreshTokenLifetime: refreshTokenLifetime,
-      alwaysIssueNewRefreshToken: this.alwaysIssueNewRefreshToken
+      alwaysIssueNewRefreshToken: this.alwaysIssueNewRefreshToken,
+      readScope: this.readScope,
     };
 
     return new Type(options).handle(request, client);