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Build Pattern: Checkin Gate

It’s common practise within a team to define a set of tasks which should be run by each developer prior to checking in. The purpose of the Check-in Gate is to attempt to ensure that all code satisfies some basic level of quality.

Like all development standards, a check-in gate helps a team stay on the same page. It eases integration, and can help give confidence as to the quality of the code checked in.

Check-in Gate with Continuous Integration

A check-in gate is typically used prior to checking in to a system which uses Continuous Integration – where the tasks in run during the check-in gate are the same tasks used as part of the continuous integration build. The main source of embarrassment associated with breaking a CI build tends to come down to the fact that the shamed individual completely forgot to run their check-in gate build.

The importance of speed

Check-in Gates need to be fast. The longer they take to run, the less developers will want to run them – this either results in less frequent check-ins or in developers not running them at all. Fewer check-ins result in more complex (and more error prone) integrations. Not running the check-in gate at all can result in a breakdown of code quality and can be a slippery slope to the gate being abandoned altogether.

Examples

The simplest example of a check-in gate would probably be ensuring that the code compiles prior to check-in. More often, the team will decide to run either some or all of a test suite. Again the constraining factor as to what you’ll want to run as part of a check-in gate is typically time – deciding how and what to run should always be defined by the team.

This entry was posted on Monday, January 29th, 2007 at 12:07 am and is filed under General. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.