jest-typeorm: A TypeScript repository from caiulucas

Hello Everyone!

So, today I'll show you how to configure your code to make tests with TypeORM and Jest.

Modules

First thing first, let's install some modules in our node environment. I'm using yarn:

yarn add jest ts-jest @types/jest -D

yarn add typeorm typescript pg

Then, let's create our tsconfig file: yarn tsc --init

Jest configs

Ok, now we need to configure our jest.config.js and there are my conigs:

module.exports = {
  clearMocks: true,
  maxWorkers: 1,
  preset: 'ts-jest',
  testEnvironment: 'node',
  testMatch: [
    '**/__tests__/**/*.[jt]s?(x)',
    '!**/__tests__/coverage/**',
    '!**/__tests__/utils/**',
    '!**/__tests__/images/**',
  ],
};

I like to make a directory named tests in the root of the project to make tests.

TypeORM configs

And I like to create a ormconfig.js. Be comfortable to make a .json or .env.

module.exports = {
  name: 'default',
  type: 'postgres',
  host: 'localhost',
  port: 5432,
  username: 'postgres',
  password: 'postgres',
  database: 'tests',
  dropSchema: true,
  logging: false,
  synchroize: true,
  migrationsRun: true,

  entities: ['src/database/entities/*.ts'],
  migrations: ['src/database/migrations/*.ts'],
  cli: {
    entitiesDir: 'src/database/entities',
    migrationsDir: 'src/database/migrations',
  },
};

So, let the dropSchema: true because this will delete your data after the tests.

I like to let migrationsRun: true to automatically run migrations before the tests.

I'm using postgres, but be comfortable to use your favorite database.

Creating connection file

Let's create a connection.ts to export some functions to run in our tests.

import {createConnection, getConnection} from 'typeorm';

const connection = {
  async create(){
    await createConnection();
  },

  async close(){
    await getConnection().close()codcd 
  },

  async clear(){
    const connection = getConnection();
    const entities = connection.entityMetadatas;

    entities.forEach(async (entity) => {
      const repository = connection.getRepository(entity.name);
      await repository.query(`DELETE FROM ${entity.tableName}`);
    });
  },
};
export default connection;

The clear method will delete all data for every single entity registered in our connection.

Creating a test

So, in your tests, just put this code:

import connection from '../src/connection';

beforeAll(async ()=>{
  await connection.create();
});

afterAll(async ()=>{
  await connection.close();
});

beforeEach(async () => {
  await connection.clear();
});

it('creates a user', () => {
  // TODO
})

And that's it :)

Github project

If you want to see the full project just click here