Continuous integration (CI) is the practice of keeping a repository of programming code frequently updated with a developer's changes. This helps ensure that multiple developers do not create programming code that conflicts with one another. Without continuous integration, conflicts that prevent code from running become quite common.
In an environment with multiple developers, it becomes necessary to form a system that enables the developers to work together. A central system of code is referred to as the code base or code repository and serves as the starting point for all of the developers' work. Each developer in the group may have a different task. One may need to improve the user interface while another may need to fix a problem in the code.
The developers may work on different aspects of the program, but there is the possibility of conflicts arising. These conflicts may lead to the program becoming unstable or even result in the application not running at all. This forces developers to spend extra time determining what particular part of the code is causing the problem. This results in a loss of productivity and time as developers are forced to fix problems that could have been avoided.
Continuous integration is the solution to this problem. Continuous integration works by ensuring that every change a developer makes is immediately updated in the code repository. When another developer accesses the code repository, he will receive a copy with the changes the previous developer has made. This helps ensure that each developer receives the most updated copy of the programming code available.
Continuous integration does not prevent integration problems. While continuous integration does help limit integration problems, these problems still arise in all multi-developer environments. Even with continuous integration, it still takes time for each individual developer to make changes to the code. This results in some changes being made to the repository without other developers realizing it.
While continuous integration is not able to alleviate all of the conflicts that arise in a multi-developer environment, it is an effective solution that maximizes productivity. It enables multiple developers to work together and create applications in a reasonable amount of time. Without it, developers would be forced to spend hours trying to rectify the problems that arise as a result of trying to integrate two different pieces of code. CI saves developers time and saves businesses and consumers money.