Add function for scope retrieval

lib/RolesModule.js

@@ -62,6 +62,22 @@ class RolesModule extends AbstractApiModule {
     }))
   }
 
+  /**
+   * Returns the list of scopes for the given role
+   * @param {String | ObjectId} _id The _id of the role
+   * @returns {Array<String>} Array of scopes
+   */
+  async getScopesForRole (_id) {
+    const allRoles = await this.find()
+    const scopes = []
+    let role = allRoles.find(r => r._id.toString() === _id.toString())
+    do {
+      scopes.push(...role.scopes)
+      role = allRoles.find(r => r.shortName === role.extends)
+    } while (role)
+    return scopes
+  }
+
   /**
    * Handles setting defined default roles when new users are added
    * @return {Promise}