hot to moke the typeORM repositery for tesing with jest in the express/koa

Question

I am calling repository methods inside of the service and now I have to write the unit test for the service. I want to moke repositery Class or Method both.

Here is the service code for which I have to write a test.

import { AttackMatrixRepo } from '../repositories/index';

export const serGetAttackMatrixDetail = async () => {
  const attMatRepo = new AttackMatrixRepo();
  const table = await attMatRepo.repGetMatric();
  return table;
};

Here is the repository code

import { AttackMatrix } from '../entities/index'; //  typeorm AttackMatrix schema
import { Repository, BaseEntity } from 'typeorm';
import { AppDataSource } from '../bootstrap/typeorm'; // typeorm connection

export class AttackMatrixRepo extends BaseEntity {
  private attackMatrixEntity: Repository<AttackMatrix>;

  constructor() {
    super();
    this.attackMatrixEntity = AppDataSource.getRepository(AttackMatrix);
  }
  public async repGetMatric() { 
    return this.attackMatrixEntity.createQueryBuilder('attMatric').getOne();
  }

  public async getMatrixByStixId({ columNames = ['*'], stixId }): Promise<AttackMatrix> {
    const tacticQueryBuilder = await this.attackMatrixEntity.createQueryBuilder('matrix');
    const query = tacticQueryBuilder.select(columNames).where('matrix.stix_id = :stixId', { stixId });
    return query.getRawOne();
  }
}