Make testing for moderator state centralized in User class

web/interfaces/user.model.ts

@@ -1,10 +1,37 @@
-export interface User {
+/* eslint-disable import/prefer-default-export */
+export class User {
+  constructor(u) {
+    this.id = u.id;
+    this.displayName = u.displayName;
+    this.displayColor = u.displayColor;
+    this.createdAt = u.createdAt;
+    this.previousNames = u.previousNames;
+    this.nameChangedAt = u.nameChangedAt;
+    this.scopes = u.scopes;
+    this.authenticated = u.authenticated;
+  }
+
   id: string;
+
   displayName: string;
+
   displayColor: number;
+
   createdAt: Date;
+
   previousNames: string[];
+
   nameChangedAt: Date;
+
   scopes: string[];
+
   authenticated: boolean;
+
+  public isModerator = (): boolean => {
+    if (!this.scopes || this.scopes.length === 0) {
+      return false;
+    }
+
+    return this.scopes.includes('moderator');
+  };
 }