knex_testing_6.ts

const di: IDIContainer = configureTestDI();
const knex = di.get<Knex>(APP_DEP.DB);
const dbSeeder = di.get<DbSeeder>(APP_DEP.TEST_DB_SEEDER);
const repo = new PostsRepo(knex);

describe("PostsRepo", () => {
    // to speed up our tests and do not trash test DB 
    // we will run test in the transaction and roll it back after execution
    beforeEach(async () => {
        await knex.raw("BEGIN");
    });
    afterEach(async () => {
        await knex.raw("ROLLBACK");
    });

    it("updates existing post", async () => {
        await dbSeeder.insert("post", { id: 12, title: "title1" });
        
        repo.updatePost(12, { title: "title 2" });   
        
        const [updatedPost] = await knex("posts").where({ id: 12 });   
        expect(updatedPost.title).toEqual("title 2");
    });
});
});