expeditavoluptas/tests/features/read-replicas.test.ts

TypeScript ORM for Node.js based on Data Mapper, Unit of Work and Identity Map patterns. Supports MongoDB, MySQL, PostgreSQL and SQLite databases as well as usage with vanilla JavaScript.

import type { MikroORM } from '@mikro-orm/core';
import { MySqlDriver } from '@mikro-orm/mysql';
import { Author2, Book2 } from '../entities-sql';
import { initORMMySql, mockLogger } from '../bootstrap';
import { Author2Subscriber } from '../subscribers/Author2Subscriber';
import { EverythingSubscriber } from '../subscribers/EverythingSubscriber';
import { FlushSubscriber } from '../subscribers/FlushSubscriber';
import { Test2Subscriber } from '../subscribers/Test2Subscriber';

describe('read-replicas', () => {

  let orm: MikroORM<MySqlDriver>;

  beforeAll(async () => orm = await initORMMySql());
  beforeEach(async () => orm.schema.clearDatabase());
  afterEach(() => {
    orm.config.set('debug', false);
    Author2Subscriber.log.length = 0;
    EverythingSubscriber.log.length = 0;
    FlushSubscriber.log.length = 0;
    Test2Subscriber.log.length = 0;
  });
  afterAll(async () => {
    await orm.schema.dropDatabase();
    await orm.close(true);
  });

  describe('when preferReadReplicas is true (default behaviour)', () => {
    test('will prefer replicas for read operations outside a transaction', async () => {
      const mock = mockLogger(orm, ['query']);

      let author = new Author2('Jon Snow', 'snow@wall.st');
      author.born = new Date('1990-03-23');
      author.books.add(new Book2('B', author));
      await orm.em.persistAndFlush(author);
      expect(mock.mock.calls[0][0]).toMatch(/begin.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[1][0]).toMatch(/insert into `author2`.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[2][0]).toMatch(/insert into `book2`.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[3][0]).toMatch(/commit.*via write connection '127\.0\.0\.1'/);

      orm.em.clear();
      author = (await orm.em.findOne(Author2, author))!;
      await orm.em.findOne(Author2, author, { refresh: true });
      await orm.em.findOne(Author2, author, { refresh: true });
      expect(mock.mock.calls[4][0]).toMatch(/select `a0`\.\*, `a1`\.`author_id` as `address_author_id` from `author2` as `a0` left join `address2` as `a1` on `a0`\.`id` = `a1`\.`author_id` where `a0`.`id` = \? limit \?.*via read connection 'read-\d'/);
      expect(mock.mock.calls[5][0]).toMatch(/select `a0`\.\*, `a1`\.`author_id` as `address_author_id` from `author2` as `a0` left join `address2` as `a1` on `a0`\.`id` = `a1`\.`author_id` where `a0`.`id` = \? limit \?.*via read connection 'read-\d'/);
      expect(mock.mock.calls[6][0]).toMatch(/select `a0`\.\*, `a1`\.`author_id` as `address_author_id` from `author2` as `a0` left join `address2` as `a1` on `a0`\.`id` = `a1`\.`author_id` where `a0`.`id` = \? limit \?.*via read connection 'read-\d'/);

      author.name = 'Jon Blow';
      await orm.em.flush();
      expect(mock.mock.calls[7][0]).toMatch(/begin.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[8][0]).toMatch(/update `author2` set `name` = \?, `updated_at` = \? where `id` = \?.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[9][0]).toMatch(/commit.*via write connection '127\.0\.0\.1'/);

      const qb = orm.em.createQueryBuilder(Author2, 'a', 'write');
      await qb.select('*').where({ name: /.*Blow/ }).execute();
      expect(mock.mock.calls[10][0]).toMatch(/select `a`.* from `author2` as `a` where `a`.`name` like \?.*via write connection '127\.0\.0\.1'/);

      await orm.em.transactional(async em => {
        const book = await em.findOne(Book2, { title: 'B' });
        author.name = 'Jon Flow';
        author.favouriteBook = book!;
        await em.flush();
      });

      expect(mock.mock.calls[11][0]).toMatch(/begin.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[12][0]).toMatch(/select.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[13][0]).toMatch(/update.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[14][0]).toMatch(/commit.*via write connection '127\.0\.0\.1'/);
    });

    test('can explicitly set connection type for find operations', async () => {
      const mock = mockLogger(orm, ['query']);
      const author = new Author2('Jon Snow', 'snow@wall.st');
      author.born = new Date('1990-03-23');
      author.books.add(new Book2('B', author));
      await orm.em.persistAndFlush(author);

      // defaults to read
      await orm.em.findOne(Author2, author, { refresh: true });
      expect(mock.mock.calls[4][0]).toMatch(/via read connection 'read-.*'/);

      // explicitly set to read
      await orm.em.findOne(Author2, author, { connectionType: 'read',refresh: true });
      expect(mock.mock.calls[5][0]).toMatch(/via read connection 'read-.*'/);

      // explicitly set to write
      await orm.em.findOne(Author2, author, { connectionType: 'write', refresh: true });
      expect(mock.mock.calls[6][0]).toMatch(/via write connection '127\.0\.0\.1'/);

      // when running in a transaction will always use a write connection
      await orm.em.transactional(async em => {
        return em.findOne(Author2, author, { connectionType: 'read', refresh: true });
      });

      expect(mock.mock.calls[7][0]).toMatch(/begin.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[8][0]).toMatch(/select.*via write connection '127\.0\.0\.1'/);
    });

    test('can explicitly set connection type for count operations', async () => {
      const mock = mockLogger(orm, ['query']);
      const author = new Author2('Jon Snow', 'snow@wall.st');
      author.born = new Date('1990-03-23');
      author.books.add(new Book2('B', author));
      await orm.em.persistAndFlush(author);

      // defaults to read
      await orm.em.count(Author2, {});
      expect(mock.mock.calls[4][0]).toMatch(/via read connection 'read-.*'/);

      // explicitly set to read
      await orm.em.count(Author2, {},{ connectionType: 'read' });
      expect(mock.mock.calls[5][0]).toMatch(/via read connection 'read-.*'/);

      // explicitly set to write
      await orm.em.count(Author2, {},{ connectionType: 'write' });
      expect(mock.mock.calls[6][0]).toMatch(/via write connection '127\.0\.0\.1'/);

      // when running in a transaction will always use a write connection
      await orm.em.transactional(async em => {
        return em.count(Author2, {},{ connectionType: 'read' });
      });
      expect(mock.mock.calls[7][0]).toMatch(/begin.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[8][0]).toMatch(/select.*via write connection '127\.0\.0\.1'/);
    });
  });

  describe('when preferReadReplicas is false', () => {
    test('will always use write connections', async () => {
      orm.config.set('preferReadReplicas', false);

      const mock = mockLogger(orm, ['query']);

      let author = new Author2('Jon Snow', 'snow@wall.st');
      author.born = new Date('1990-03-23');
      author.books.add(new Book2('B', author));
      await orm.em.persistAndFlush(author);
      expect(mock.mock.calls[0][0]).toMatch(/begin.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[1][0]).toMatch(/insert into `author2`.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[2][0]).toMatch(/insert into `book2`.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[3][0]).toMatch(/commit.*via write connection '127\.0\.0\.1'/);

      orm.em.clear();
      author = (await orm.em.findOne(Author2, author))!;
      await orm.em.findOne(Author2, author, { refresh: true });
      await orm.em.findOne(Author2, author, { refresh: true });
      expect(mock.mock.calls[4][0]).toMatch(/select `a0`\.\*, `a1`\.`author_id` as `address_author_id` from `author2` as `a0` left join `address2` as `a1` on `a0`\.`id` = `a1`\.`author_id` where `a0`.`id` = \? limit \?.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[5][0]).toMatch(/select `a0`\.\*, `a1`\.`author_id` as `address_author_id` from `author2` as `a0` left join `address2` as `a1` on `a0`\.`id` = `a1`\.`author_id` where `a0`.`id` = \? limit \?.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[6][0]).toMatch(/select `a0`\.\*, `a1`\.`author_id` as `address_author_id` from `author2` as `a0` left join `address2` as `a1` on `a0`\.`id` = `a1`\.`author_id` where `a0`.`id` = \? limit \?.*via write connection '127\.0\.0\.1'/);

      author.name = 'Jon Blow';
      await orm.em.flush();
      expect(mock.mock.calls[7][0]).toMatch(/begin.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[8][0]).toMatch(/update `author2` set `name` = \?, `updated_at` = \? where `id` = \?.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[9][0]).toMatch(/commit.*via write connection '127\.0\.0\.1'/);

      const qb = orm.em.createQueryBuilder(Author2, 'a', 'write');
      await qb.select('*').where({ name: /.*Blow/ }).execute();
      expect(mock.mock.calls[10][0]).toMatch(/select `a`.* from `author2` as `a` where `a`.`name` like \?.*via write connection '127\.0\.0\.1'/);

      await orm.em.transactional(async em => {
        const book = await em.findOne(Book2, { title: 'B' });
        author.name = 'Jon Flow';
        author.favouriteBook = book!;
        await em.flush();
      });

      expect(mock.mock.calls[11][0]).toMatch(/begin.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[12][0]).toMatch(/select.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[13][0]).toMatch(/update.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[14][0]).toMatch(/commit.*via write connection '127\.0\.0\.1'/);
    });

    test('can explicitly set connection type for find operations', async () => {
      orm.config.set('preferReadReplicas', false);

      const mock = mockLogger(orm, ['query']);
      const author = new Author2('Jon Snow', 'snow@wall.st');
      author.born = new Date('1990-03-23');
      author.books.add(new Book2('B', author));
      await orm.em.persistAndFlush(author);

      // defaults to write
      await orm.em.findOne(Author2, author, { refresh: true });
      expect(mock.mock.calls[4][0]).toMatch(/via write connection '127\.0\.0\.1'/);

      // explicitly set to read
      await orm.em.findOne(Author2, author, { connectionType: 'read',refresh: true });
      expect(mock.mock.calls[5][0]).toMatch(/via read connection 'read-.*'/);

      // explicitly set to write
      await orm.em.findOne(Author2, author, { connectionType: 'write', refresh: true });
      expect(mock.mock.calls[6][0]).toMatch(/via write connection '127\.0\.0\.1'/);

      // when running in a transaction will always use a write connection
      await orm.em.transactional(async em => {
        return em.findOne(Author2, author, { connectionType: 'read', refresh: true });
      });

      expect(mock.mock.calls[7][0]).toMatch(/begin.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[8][0]).toMatch(/select.*via write connection '127\.0\.0\.1'/);
    });

    test('can explicitly set connection type for count operations', async () => {
      orm.config.set('preferReadReplicas', false);

      const mock = mockLogger(orm, ['query']);
      const author = new Author2('Jon Snow', 'snow@wall.st');
      author.born = new Date('1990-03-23');
      author.books.add(new Book2('B', author));
      await orm.em.persistAndFlush(author);

      // defaults to write
      await orm.em.count(Author2, {});
      expect(mock.mock.calls[4][0]).toMatch(/via write connection '127\.0\.0\.1'/);

      // explicitly set to read
      await orm.em.count(Author2, {},{ connectionType: 'read' });
      expect(mock.mock.calls[5][0]).toMatch(/via read connection 'read-.*'/);

      // explicitly set to write
      await orm.em.count(Author2, {},{ connectionType: 'write' });
      expect(mock.mock.calls[6][0]).toMatch(/via write connection '127\.0\.0\.1'/);

      // when running in a transaction will always use a write connection
      await orm.em.transactional(async em => {
        return em.count(Author2, {},{ connectionType: 'read' });
      });
      expect(mock.mock.calls[7][0]).toMatch(/begin.*via write connection '127\.0\.0\.1'/);
      expect(mock.mock.calls[8][0]).toMatch(/select.*via write connection '127\.0\.0\.1'/);
    });
  });

});