Jest Lunch and Learn

Prerequisites

Clone this repository (already done!)
Install docker and docker-compose. You can do so from the links in this Github comment, buried under a polite conversation about whether docker was truly open source or freeware.

Run docker-compose up server-install. This will install the node modules that the server and tests will need to run in a volume inside docker. You may also choose to run yarn install or npm install to install your own node_modules folder, but docker won't use this.
Run docker-compose up adminer db_test. This will start the test database, which on first startup will create an initial database, and adminer, a mysql UI. It's a simple php server, but quite unbreakable.
In a browser, navigate to http://localhost:8081 and log in with these values:

Server: db_test
Username: root
Password: example
Database: database

If it complains about an invalid database, that's because mysql is still setting up the initial database. It should resolve in a couple minutes.

This repo contains some docker containers:

MySQL Databases
A nodeJS server running express, which you can view at http://localhost:8080 (once its docker container is running.)
A jest test container, for running tests that require a server or a database connection.
Adminer, a MySQL gui. You can use adminer by navigating to http://localhost:8081 (once it is running).

To run Jest tests, run docker-compose up server-test. This will start the server container and execute a yarn command inside it to run the tests.