Continuous integration

While continuous integration (CI) technically means merging to master frequently, in modern web development it usually means the process of tests being run automatically on each commit. It’s often done with a service like CircleCI that monitors our commits on GitHub, runs the tests, and provides a webpage for each commit where we can view the test output. We can also set it up to do something after the test, such as:

• Mark a pull request as passing or failing the tests.
• Mark that commit as passing or failing by adding a red X or green checkmark next to the commit in the repository’s history.
• If successful, deploy the code to a server—for example the staging or production server.

When the last step is included, the process may also be called continuous delivery or continuous deployment.