added match by role name functionality to roles plugin

backend/src/plugins/ZeppelinPlugin.ts

@@ -16,6 +16,7 @@ import {
   trimEmptyStartEndLines,
   trimIndents,
   UnknownUser,
+  resolveRoleId,
 } from "../utils";
 import { Invite, Member, User } from "eris";
 import DiscordRESTError from "eris/lib/errors/DiscordRESTError"; // tslint:disable-line
@@ -237,6 +238,16 @@ export class ZeppelinPlugin<TConfig extends {} = IBasePluginConfig> extends Plug
     return user;
   }
 
+  /**
+   * Resolves a role from the passed string. The passed string can be a role ID, a role mention or a role name.
+   * In the event of duplicate role names, this function will return the first one it comes across.
+   * @param roleResolvable 
+   */
+  async resolveRoleId(roleResolvable: string): Promise<string> {
+    const roleId = await resolveRoleId(this.bot, this.guildId, roleResolvable);
+    return roleId;
+  }
+
   /**
    * Resolves a member from the passed string. The passed string can be a user id, a user mention, a full username (with discrim), etc.
    * If the member is not found in the cache, it's fetched from the API.