const repo = new PostsRepo(knex);
it("updates existing post", async () => {
    await knex("users").insert({ id: 1, first_name: "John", last_name: "doe" });
    await knex("posts").insert({ id: 2, user_id: 1, title: "Post Title", body: "body"});

    repo.updatePost(1, { title: "title 2" });
    const [updatedPost] = await knex("posts").where({ id: 2 });

    expect(updatedPost.title).toEqual("title 2");
});