Git branching strategy integated with testing/QA process

David Lin picture David Lin · Aug 22, 2013 · Viewed 39.4k times · Source

Our development team has been using the GitFlow branching strategy and it has been great !

Recently we recruited a couple testers to improve our software quality. The idea is that every feature should be tested/QA by a tester.

In the past, developers work on features on separate feature branches and merge them back to the develop branch when done. The developer will test his work himself on that feature branch. Now with testers, we start asking this Question

On which branch should the tester test new features ?

Obviously, there are two options:

  • on the individual feature branch
  • on the develop branch

Testing On Develop Branch

Initially, we believed this is the sure way to go because:

  • The feature is tested with all other features merged to the develop branch since it's development started.
  • Any conflicts can be detected earlier than later
  • It makes the tester's job easy, he is only dealing with one branch (develop) at all time. He doesn't need to ask the developer about which branch is for which feature ( feature branches are personal branches managed exclusively and freely by relevant developers )

The biggest problems with this is:

  • The develop branch is polluted with bugs.

    When the tester finds bugs or conflicts, he reports them back to the developer, who fixes the issue on the develop branch (the feature branch were abandoned once merged ), and there could be more fixes required afterward. Multiple subsequence commits or merges (if a branch is recreated off develop branch again for fixing the bugs) makes rolling back the feature from the develop branch very difficult if possible. There are multiple features merging to and being fixed on the develop branch at different times. This creates a big issue when we want to create a release with just some of the features in the develop branch

Testing On Feature Branch

So we thought again and decided we should test features on the feature branches. Before we test, we merge the changes from the develop branch to the feature branch ( catch up with the develop branch ). This is good:

  • You still test the feature with other features in the mainstream
  • Further development ( e.g. bug fix, resolving conflict ) will not pollute the develop branch;
  • You can easily decide not to release the feature until it is fully tested and approved;

However, there are some drawbacks

  • The tester has to do the merging of the code, and if there's any conflict (very likely), he has to ask the developer for help. Our testers specialize in test and are not capable of coding.
  • a feature could be tested without the existence of another new feature. e.g. Feature A and B are both under test at the same time, the two features are unaware of each other because neither of them has been merged to the develop branch. These means you will have to test against the develop branch again when both of the features are merged to the develop branch anyway. And you have to remember to test this in the future.
  • If Feature A and B are both tested and approved, but when merged a conflict is identified, both of the developers for both features believe it is not his own fault/job because his feature branch past the test. There is an extra overhead in communication, and sometimes whoever resolving the conflict is frustrated.

Above is our story. With limited resource, I would like to avoid testing everything everywhere. We are still looking for a better way to cope with this. I would love to hear how other teams handle this kind of situations.

Answer

Aspasia picture Aspasia · Sep 19, 2013

The way we do it is the following:

We test on the feature branches after we merge the latest develop branch code on them. The main reason is that we do not want to "pollute" the develop branch code before a feature is accepted. In case a feature would not be accepted after testing but we would like to release other features already merged on develop that would be hell. Develop is a branch from which a release is made and thus should better be in a releasable state. The long version is that we test in many phases. More analytically:

  1. Developer creates a feature branch for every new feature.
  2. The feature branch is (automatically) deployed on our TEST environment with every commit for the developer to test.
  3. When the developer is done with deployment and the feature is ready to be tested he merges the develop branch on the feature branch and deploys the feature branch that contains all the latest develop changes on TEST.
  4. The tester tests on TEST. When he is done he "accepts" the story and merges the feature branch on develop. Since the developer had previously merged the develop branch on feature we normally don't expect too many conflicts. However, if that's the case the developer can help. This is a tricky step, I think the best way to avoid it is to keep features as small/specific as possible. Different features have to be eventually merged, one way or another. Of course the size of the team plays a role on this step's complexity.
  5. The develop branch is also (automatically) deployed on TEST. We have a policy that even though the features branch builds can fail the develop branch should never fail.
  6. Once we have reached a feature freeze we create a release from develop. This is automatically deployed on STAGING. Extensive end to end tests take place on there before the production deployment. (ok maybe I exaggerate a bit they are not very extensive but I think they should be). Ideally beta testers/colleagues i.e. real users should test there.

What do you think of this approach?