Jest how to assert typeorm Brackets

Question

I am using typeorm Brackets as follows:

const getQuery = this.repository.createQueryBuilder("user");

    const brackets = new Brackets((qb) => {
      qb.where("user.name ~* :name", { name: "aaa" });
      qb.orWhere("user.name.~* :name", {
        name: "bbb",
      });
    });

    getQuery.andWhere(brackets);

    const result = (await getQuery.getMany());

How can I test it properly in unit test? I think the real concern is the Bracket method, can we just test it as a normal function like:

expect(repository.andWhere).toHaveBeenNthCalledWith(new Brackets((qb) => {
        qb.where("user.name ~* :name", { name: "aaa" });
        qb.orWhere("user.name ~* :name", {
          name: "bbb",
        });
      }));

The error I got was: on the service, not too sure how I can test it properly: TypeError: qb.where is not a function

Answer 1

I recently stuck on this too. What I did was mock the typeorm Brackets class and the callback functions, so that we could spy on the called functions.

const bracketsMock = {
  where: jest.fn().mockReturnThis(),
  orWhere: jest.fn().mockReturnThis(),
};

jest.mock('typeorm', () => {
  return { 
    ...jest.requireActual('typeorm'),
    Brackets: jest.fn(function(cb) {
      cb(bracketsMock)
    }) 
  };
});

then we spy on the brackets callback:

const bracketWhereSpy = jest.spyOn(bracketsMock, 'where');
const bracketOrWhereSpy = jest.spyOn(bracketsMock, 'orWhere');
expect(bracketWhereSpy).toHaveBeenCalled();
expect(bracketOrWhereSpy).toHaveBeenCalled();