jest-testcontainers

Jest preset for running docker containers with your tests. Primary purpose is to make it possible to use any database in integration tests. Since it uses docker images, custom database images with different plugins/configurations can be used in the integration tests. Using testcontainers-node under the hood. Inspired by @shelf/jest-mongodb.

Usage

Install

Docker should be installed on your system. If running inside a CI pipeline, see FAQ.md.

npm install --save-dev @trendyol/jest-testcontainers

Edit Jest Config

On your jest.config.js add the project as the preset.

module.exports = {
  preset: '@trendyol/jest-testcontainers'
};

Declare Containers To Run

Create a file called jest-testcontainers-config.js and put it to root of your project, where you run npm test. If you would like to put this file somewhere else, you can use the JEST_TESTCONTAINERS_CONFIG_PATH environment variable to define a relative or absolute path. A sample configuration file;

module.exports = {
  redis: {
    image: 'redis',
    tag: 'alpine3.12',
    ports: [6379],
    env: {
      EXAMPLE: 'env',
    },
    wait: {
      type: 'text',
      text: 'Ready to accept connections'
    }
  },
//   more: {
//     image: 'any-docker-image', // postgresql, mongodb, neo4j etc.
//     ports: [1234, 4567], // ports to make accessible in tests
//     cmd: ['echo', '"hi"']
//   },
};

Connect To Containers

Every containers IP and Port info is registered to global variables to be used by your tests.

const redis = require('redis');
const { promisify } = require('util');

describe('testcontainers example suite', () => {
  let redisClient;

  beforeAll(() => {
    const redisConnectionURI = `redis://${global.__TESTCONTAINERS_REDIS_IP__}:${global.__TESTCONTAINERS_REDIS_PORT_6379__}`;
    redisClient = redis.createClient(redisConnectionURI);
    
    // if you have declared multiple containers, they will be available to access as well. e.g.
    // `global.__TESTCONTAINERS_${CONFIG_KEY}_IP__`
    // `global.__TESTCONTAINERS_${CONFIG_KEY}_PORT_${CONFIG_PORT}__`
  });

  afterAll(() => {
    redisClient.quit();
  });
  
  it('write should be ok', async () => {
    // Arrange
    const setAsync = promisify(redisClient.set).bind(redisClient);

    // Act
    const setResult = await setAsync('test', 73);

    // Assert
    expect(setResult).toEqual('OK');
  });
});

Documentation

Detailed documentation of the jest-testcontainers-config.js can be found at DOC.md.

Examples

• examples/01-basic-redis showcases writing integration tests against Redis. You can use npm run build && npm run example:redis command to run this example locally.
• examples/02-typescript-redis same test cases as in example #1. However using Typescript instead of JavaScript. You can use npm run build && npm run example:redis-typescript to run this example locally.
• examples/03-docker-compose same test cases as examples #1 and #2, however using Docker Compose to build the container. You can use npm run build && npm run example:docker-compose to run this example locally.
• Yengas/nodejs-postgresql-testcontainers showcases writing integration tests against PostgreSQL with schema migration and Typescript. You can check out the project page for more details.

Watch mode support

Starting with version 2.0.0 containers will not be stopped if Jest is started in watch mode. This greatly improves development productivity if your containers have a slow startup time (ex. Elasticsearch). This comes with the price that you have to be mindful that containers will be reused between watch test executions and you need to do proper cleanup in your after hooks.

If you want to disable this behavior you can set the JEST_TESTCONTAINERS_RESTART_ON_WATCH environment variable.

Wondering what will happen when those containers are not stopped when Jest is exited - testcontainer's ryuk will take care of them.

License

This project is licensed under the MIT License