https://www.newline.co/fullstack-react/30-days-of-react/day-29/
Continuous Integration
Today we'll look through some continuous integration solutions available for us to run tests against as well as implement one to test our application in the cloud.
We've deployed our application to the "cloud", now we want to make sure everything runs as we expect it. We've started a test suite, but now we want to make sure it passes completely before we deploy.
We could set a step-by-step procedure for a developer to follow to make sure we run our tests before we deploy manually, but sometimes this can get in the way of deployment, especially under high-pressure deadlines in the middle of the night. There are better methods.
Testing then deployment