generator-nest-js-boilerplate/generators/auth/templates/mongodb/jwt/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 { Request } from 'express';
import { CanActivate, ExecutionContext, Injectable } from '@nestjs/common';
import { Reflector } from '@nestjs/core';

import { RolesEnum } from '@decorators/roles.decorator';
import { UserDocument } from '@v1/users/schemas/users.schema';

@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 request: Request = context.switchToHttp().getRequest();
    const user = request.user as UserDocument;

    return roles.some((role: RolesEnum) => user.roles.includes(role as RolesEnum));
  }
}