generator-nest-js-boilerplate/generators/auth/templates/mysql/passportLocal/src/guards/roles.guard.ts

This generator will help you to build your own Nest.js Mongodb API using TypeScript 4

import _ from 'lodash';
import { CanActivate, ExecutionContext, Injectable } from '@nestjs/common';
import { Reflector } from '@nestjs/core';

import { RolesEnum } from '@decorators/roles.decorator';

@Injectable()
export default class RolesGuard implements CanActivate {
  constructor(
    private reflector: Reflector,
  ) {}

  async canActivate(context: ExecutionContext): Promise<boolean> {
    const roles = this.reflector.get<RolesEnum[]>('roles', context.getHandler());

    if (_.isEmpty(roles)) {
      return true;
    }

    const http = context.switchToHttp();
    const req = http.getRequest();
    const res = http.getResponse();

    if (req.isUnauthenticated()) {
      return res.redirect('/v1/auth/login');
    }

    const haveAccess: boolean = roles.some((role) => req?.user?.roles.includes(role));

    if (!haveAccess) {
      return res.redirect('/v1/home');
    }

    return true;
  }
}