Continuous Integration (short CI) is the practice of merging all developer working copies to a shared mainline several times a day.
So for every proposed change to the source code the following is done automatically:
After the system is done with all these tasks the developer can view build reports highlighting occurred errors and problems. We are using Jenkins as our CI system.
All of this automatically kicks in when you open a Pull Request on GitHub. You will notice a checks block at the end of the pull request page:
Click on the Details link to find out the reason for a failed check. If you add more commits to this pull request all checks are run again.
You can have the CI system testing all your branches in your fork of OGS even before creating a pull request. See the page on Jenkins for further information.