Git branching strategy integated with testing/QA process

Question

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.

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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.

Univalve

This question seems like it's a better fit for Programmers, since it doesn't deal with a programming problem, but rather a development process. Can someone migrate it? – Chappelka

elated question: How should Git Flow work with QA testing both a release and a new feature? – Cheeks

Our model is exactly the same. I'm interested in hearing about how your QA team reports issues on feature branches differently from issues in the field or issues during UAT process (if you have one). We use Atlassian JIRA and we have a different workflow for the two. – Cockspur

Deciding the same thing right now. Plus, as our environment is a java spring application, it takes around 20 minutes to build and deploy to test environment. Happy someone asked the same doubts I had. – Villainage

The first drawback isn't inherent to the process of testing on feature branches. Tools like Github Enterprise and Bitbucket have the ability to require approval for pull requests and the person responsible for QA can approve signaling to the developer that they are free to merge into develop. – Florri

A couple of things I would add to the drawbacks: 1) There are issues with either requiring testers to deploy features to their local box or using CI to deploy features to a shared QA environment. 2) Features are often progressive (e.g. story 1 adds feature X with supporting infrastructure, story 2 builds on the infrastructure of story 1 to add feature Y). Only allowing completed features to be merged to develop means you either can't squash feature commits (more junk commits than feature bug fixes causes) or you can't start story 2 until story 1 is complete. – Florri

It's funny how some questions get closed for seeming broad even though they are about programming and programming languages, and yet something like this is acceptable on here. – Wichita

Answer 1

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 the implementation and the feature is ready to be tested they reabse the develop branch on the feature branch and deploy the feature branch that contains all the latest develop changes on TEST.
4. The tester tests on TEST. When they are done they "accept" the story and merge the feature branch on develop. Since the developer had previously rebased the develop branch on the feature one we 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?

Buchmanism

How do we make sure that feature1 and feature2 which were tested independently are also good to go together (as mentioned in the question)? – Enterectomy

we do indirectly, by merging one and then the other one to develop. It is step 4 of the process above and it has to do with chronological order. So if feature 2 is ready to be merged but feature 1 was already merged, the feature 2 developer and tester have to make sure that their merge will work. – Buchmanism

I think anyway according to this git branching model you are not supposed to merge two feature branches with each other. – Buchmanism

We've run into problems in step 6, especially in crunch times with multiple features being moved to develop, because of non-trivial merges that happen after QA has signed off on the feature branch, despite merging devlop to feature as late as possible. I commented in a little more detail here: https://mcmap.net/q/159837/-how-should-git-flow-work-with-qa-testing-both-a-release-and-a-new-feature – Cheeks

@JoshuaGoldberg I know what you mean and agree that is the trickiest part. One way I can think of reducing the complexity is create regular, small releases, with very few/even just one features. Or features that don't touch same parts of the code. And anyway the release should be thoroughly tested as a whole before it hits production imho. – Buchmanism

Do you have a complete TEST Environment (DB, Server, Client, etc) for each feature branch? Or do they share the Environment and just have different names (e.g. app-name_feature1- app-name_feature2, etc.) – Ingaingaberg

@Ingaingaberg one environment should be enough and test one feature branch at the time. – Buchmanism

So this model still doesn't allow for concurrent testing of features to occur without having to re-test after every merge to develop? – Blockhead

Since we promote builds (we use the same build on each env to test before production) this method does not work well for us. – Agha

How do you keep E2E tests updated? Do you just create them when the feature lands on the TEST environment? Or does the developer merge E2E tests? This is assuming that automated unit tests are already defined and merged. Are automated E2E tests required for your sign off? – Ismaelisman

@Blockhead not sure how you would know that everytihning works before rebasing on develop. But if you know how I am curious! – Buchmanism

@Ismaelisman I would treat them as all other tests but that depends on your particular setting: who writes those tests? Are they on the same repo? Are they part of the continuous integration? – Buchmanism

@Buchmanism if you merge/rebase develop into your feature branch, it will be in the same state as develop will be in after that feature branch is merged into it. :) of course this is not ideal since develop could change before you are ready to merge... – Blockhead

@Blockhead that's what I suggested above, I prefer rebase. But yeah if develop changes in the mean time it can be a problem. For a small team it works – Buchmanism

@Buchmanism yeah the annoying this is the tests are in a different repo and we have someone who has a role for writing tests. Naturally we have to have good communication with them but sometimes, depending how complex the feature is to test in an automative way, we do manual testing first and then circle back to automate the test cases. I was just curious if you had a different process. – Ismaelisman

@GlenThomas this is a pretty old post. The PR/code review would happen in step 4 in order to merge the feature branch to develop. – Buchmanism

@Buchmanism so the tester is creating a PR for code they didn't write? – Hypothec

@GlenThomas sorry I meant 3. So the developer rebases develop on the feature branch and then deploys on TEST. Whether the tester will also review the code or not that depends if the testers are also developers or not. In any case when tests and review are done and fixes are made on the future branch, the PR can be merged to develop. – Buchmanism

What happens if there is bug after merging feature branch into develop branches? Should the bug be fixed in a new feature branch or in the develop branch? – Greyso

@Greyso my opinion is that if branch has already been merged to master it should be treated like a hotfix on master. If not, probably it has to do with one of the futures and should better fixed on there. Please have a look here nvie.com/posts/a-successful-git-branching-model – Buchmanism

@Buchmanism one thing I do not understand, when we are publishing the TEST from feature branches. Wouldn't we need multiple TEST environment, in fact as many as the no of features currently in development? – Bynum

@Bynum I think this is very dependent on the team. For example if you have one test environment per team of 5-6 people, it is easy to coordinate and test one feature at the time. Since features are independent once it is done the next is deployed. If the team releases and tests very often then more test environments would be needed or maybe virtual/cloud ad hock environments. – Buchmanism

Hello @Buchmanism Thanks for sharing this info. I would like to ask how do you deploy a feature branch for testing? I am using GCP and trying to figure out this thing. Thanks – Robeson

what do Google and facebook do? Does this strategy hold true for today? – Nave

ok, what if the QA accepts the change on Develop, however Product Owners and Customers don't like the feature? They dev branch is still polluted, so isolating by testing feature branches still does not work ! – Nave

Hi @Bill. This is very dependent on the infrastructure setup and deployment method. Back then when I answered the question we had a dedicated self managed test server and we deployed using a script. These days I work with AWS and depending on the case I use a manually triggered github action and then possibly a docker image and cloudformation to spin up a stack with a spot instance that starts the container (and anything else needed). I think this is highly depended to the use case but I am sure that GCP must support such automation from templates or something similar. – Buchmanism

Hi @mattsmith5: the giflow branching strategy is somewhat outdated as announced by its author nvie.com/posts/a-successful-git-branching-model and he clearly mentions that such strategies highly depend on the context. There is an interesting discussion about it in this podcast codingblocks.net/podcast/comparing-git-workflows – Buchmanism

Hi @mattsmith5: as mentioned above the way a company works varies a lot on its size, testing strategy, workflow etc. In all cases at some point the feature has to be be approved and then merged to the develop branch. If that happens after the Product Owner approves a simple solution is to use the feature branch till that point. If you want to test different features with customers then you need a/b testing as discussed here softwareengineering.stackexchange.com/questions/361589/…. Also tags are your friends! – Buchmanism

with many parallel features in simultaneous/parallel development how do you handle parallel testing for multiple features in multiple staging envs? – Schutzstaffel

What happens in your workflow if testers find a problem? Does the developer create a new feature branch to resolve that or do they somehow re-open the previous feature branch? – Forward

The feature branch is (automatically) deployed on our TEST environment. How is that automatically? How do you automate that? For every push on feature-whatever branch what do you do? – Merci

@DanielLizik I have never worked with multiple staging environments before, even though it is probably possible. I have worked with multiple test ones for every feature branch. In general the idea is the same: every time you are done with a feature branch you merge it back to develop. You can decide how often you want to deploy. In some cases you wait for several features to be merged before creating a release and in some cases (ideal) you deploy one by one. That requires automat deployments – Buchmanism

@Forward there are different ways to do this in terms of branching. Probably what you suggesting i.e. create a branch of develop, fix it, merge it and create a new release is the cleanest (patch release) – Buchmanism

@Merci automated deployments is a whole chapter and there are many ways to do it. In a small coordinated team you can just indeed deploy with every push. You can also spin an environment per feature branch if you are using cloud services and destroy it when you merge – Buchmanism

@Buchmanism late response 1.5 years later...my team "solved" this issue via a combination of having qa1/2/3 envs + trunk based development + feature flags. N branches can be created with N flags toggled and deployed to dedicated envs for testing, each of these branches points to the trunk branch. we can also deploy the trunk branch itself to a pilot env for UAT and if necessary raise release candidate patches prior to production deploy, this strategy greatly boosted our team's velocity. – Schutzstaffel

Answer 2

Before test, we merge the changes from the develop branch to the feature branch

No. Don't, especially if 'we' is the QA tester. Merging would involve resolving potential conflicts, which is best done by developers (they know their code), and not by QA tester (who should proceed to test as quickly as possible).

Make the developer do a rebase of his/her feature branch on top of devel, and push that feature branch (which has been validated by the developer as compiling and working on top of the most recent devel branch state).
That allows for:

• a very simple integration on the feature branch (trivial fast-forward merge).
• or, as recommended by Aspasia below in the comments, a pull request (GitHub) or merge request (GitLab): the maintainer does a merge between the feature PR/MR branch and develop, but only if not conflict are detected by GitHub/GitLab.

Each time the tester detects bug, he/she will report it to the developer and delete the current feature branch.
The developer can:

• fix the bug
• rebase on top of a recently fetched develop branch (again, to be sure that his/her code works in integration with other validated features)
• push the feature branch.

General idea: make sure the merge/integration part is done by the developer, leaving the testing to the QA.

Sample

Are you saying "don't use merge, use rebase instead"? If so, I'm confused, given the Git FAQ on the difference between the two: git.wiki.kernel.org/index.php/… – Granville

@VickiLaidler yes, if the feature branch is rejected by QA, the developer has to rebase, not merge (https://mcmap.net/q/12940/-when-do-you-use-git-rebase-instead-of-git-merge) – Sample

@VonC: Wow, I'm very surprised nobody else is grokking this. What you recommend is clearly the right way to do this. I'd even go so far as to argue that you don't need to rebase every time, as long as the feature branch was started at a stable point, and isn't too far behind. But if we are going to insist that we sync the feature branch with develop, then absolutely rebase, don't merge. Junio Hamano's comment on this article explains this quite well: kentnguyen.com/development/visualized-git-practices-for-team/… – Behindhand

@DanMoulding I agree. I am used with that kind of workflow (rebase locally, then push), as it is enforced by most other modern tool: I am using RTC right now (Rational Ream Concert: jazz.net/products/rational-team-concert) which has the same workflow. I described the Git one in https://mcmap.net/q/13255/-git-workflow-and-rebase-vs-merge-questions and https://mcmap.net/q/12940/-when-do-you-use-git-rebase-instead-of-git-merge a few years ago. – Sample

@Sample I completely agree but there are some issues: 1) Deleting the branch impacts other tooling, like Stash Pull Requests (deleting branch closes the PR). Prefer force pushing. 2) If it's a big feature branch where during its lifetime two people collaborated, merges would have been preferred over rebasing. Rebasing it at the end creates conflict nightmare as the merge commits will be removed, and if code depended on those merge changes, it is non trivial to fix – Cockspur

@Cockspur I agree this workflow doesn't fit all situation. And I mentioned force push before (https://mcmap.net/q/159838/-upstream-merge-commits-in-pull-request). – Sample

Looking back at my answer I would also do a rebase and not a merge for cleaner history. – Buchmanism

"No. Don't, especially if 'we' is the QA tester." No reason provided, therefore this review is not useful – Eunuchize

@SteveHarrison Right: I have added the reason (which is repeated in the last sentence of this answer) – Sample

"General idea: make sure the merge/integration part is done by the developer, leaving the testing to the QA." is not a reason for "Before test, we(QA Tester) merge the changes from the develop branch to the feature branch" – Eunuchize

Rebasing should be only used on private developer histories (i.e. histories that haven't been shared with other developers yet or that were worked on by other developers). This may not always be sensible for all environments. – Aweigh

@Sample For your first point the feature branch is already rebased on top of develop, no merge conflicts are expected. Who does all this is dependent on the team setup of course. Our QAs were developers as well. – Buchmanism

@Buchmanism If the feature branch is already rebased on top of develop, then you don't merge develop to feature. – Sample

@Sample sorry I meant it the other way round obviously I think you know what I mean, its the developers responsibility to rebase develop on top of the feature branch before creating the PR – Buchmanism

@Buchmanism Strange: rebasing develop would change its history, which is not practical... – Sample

@Sample oh the confusion. How I normally work is: rebase the feature branch like: git rebase -i develop, decide which commits-messages I keep and then create a pull request. If that goes well we merge the pr. – Buchmanism

@Buchmanism OK, this time, I get it ;) a git rebase -i develop is not "rebasing develop", it is "rebasing (the current branch) on top of develop". If that current branch is feature, that makes sense! – Sample

@Sample I know, that's what happens when you type fast between other things. So to reply to your "If the feature branch is already rebased on top of develop, then you don't merge develop to feature.": no but you do merge the pr. – Buchmanism

@Buchmanism is the PR done between feature and develop? As in: 'I will apply that PR from feature to develop"? – Sample

@Sample yes between feature and develop. What is called "merge pull request" in github. Why are you asking this question? – Buchmanism

@Buchmanism just to make sure what I need to amend in my answer: it is still a merge from feature to master, but not a fast-forward one as I describe: rather, a pull request to be accepted/merged. – Sample

@Sample yes what I am talking about is merging a PR. However, if you have rebased before merging the PR does exactly the same in the background, a fast forward like described here help.github.com/articles/about-pull-request-merges/…. Personally I prefer PRs for several reasons. One of them is they can be nicely connected to github issues and automatically close them on merge. Other reasons are the descriptions can be useful for the reviewer to understand what has been done and what needs to be checked and they are very easy to revert if needed. – Buchmanism

@Buchmanism Good points. I have included pull-requests in the answer for more visibility. – Sample

@Sample " Each time the tester detects bug, he/she will report it to the developer and delete the current feature branch. " What is the point of deleting the current feature branch? – Greatcoat

@Greatcoat Just making sure the branch is not merged by mistake. (I suppose that it is what I was going for 5 years ago) – Sample

Answer 3

The best approach is continuous integration, where the general idea is to merge the feature branches into the developer branch as frequently as possible. This reduces on the overhead of merging pains.

Rely on automated tests as much as possible, and have builds automatically kick off with unit tests by Jenkins. Have the developers do all the work with merging their changes into the main branch and provide unit tests for all their code.

The testers/QA can take participate in code reviews, check off on unit tests and write automated integration tests to be added to the regression suite as features are completed.

For more info check out this link.

Redshank

You can still do CI with branches + rebasing in Git. – Cockspur

Answer 4

We use what we call "gold", "silver", and "bronze". This could be called prod, staging, and qa.

I've come to call this the melting pot model. It works well for us because we have a huge need for QA in the business side of things since requirements can be hard to understand vs the technicals.

When a bug or feature is ready for testing it goes into "bronze". This triggers a jenkins build that pushes the code to a pre-built environment. Our testers (not super techies by the way) just hit a link and don't care about the source control. This build also runs tests etc. We've gone back and forth on this build actually pushing the code to the testing\qa environment if the tests (unit, integration, selenium ) fail. If you test on a separate system ( we call it lead ) you can prevent the changes from being pushed to your qa environment.

The initial fear was that we'd have lots of conflicts between this features. It does happen were feature X makes it seem like feature Y is breaking, but it is infrequent enough and actually helps. It helps get a wide swath of testing outside what seems is the context of the change. Many times by luck you will find out how your change effects parallel development.

Once a feature passes QA we move it into "silver" or staging. A build is ran and tests are run again. Weekly we push these changes to our "gold" or prod tree and then deploy them to our production system.

Developers start their changes from the gold tree. Technically you could start from the staging since those will go up soon.

Emergency fixes are plopped directly into the gold tree. If a change is simple and hard to QA it can go directly into silver which will find its way to the testing tree.

After our release we push the changes in gold(prod) to bronze(testing) just to keep everything in sync.

You may want to rebase before pushing into your staging folder. We have found that purging the testing tree from time to time keeps it clean. There are times when features get abandoned in the testing tree especially if a developer leaves.

For large multi-developer features we create a separate shared repo, but merge it into the testing tree the same when we are all ready. Things do to tend bounce from QA so it is important to keep your changesets isolated so you can add on and then merge/squash into your staging tree.

"Baking" is also a nice side effect. If you have some fundamental change you want to let sit for a while there is a nice place for it.

Also keep in mind we don't maintain past releases. The current version is always the only version. Even so you could probably have a master baking tree where your testers or community can bang on see how various contributors stuff interact.

Prowl

Answer 5

In our company we cant use agile development and need approval for every change by business, this causes a lot of issues.

Our approach for working with GIT is this;

We have implemented "Git Flow" in our company. We using JIRA and only approved JIRA Tickets should be go to production. For Test approval we exted it with a created a seperate Test-Branch.

Steps for processing a JIRA Tickets are:

1. Create a new Branch from Develop-Branch
2. Do the code Changes on the Feature-Branch
3. Pull from Feature the Changes to the Test/QA Branch
4. After business approval we pull the change from feature branch into develop
5. The develop goes frequently in a release and then finally master branch

Splitting each request in an own feature ensures, only approved changes went to production.

The complete process looks like this:

Nelly

So this process only allows for a single feature to be tested at once? That seems like a huge bottleneck for a big dev team. – Millstream

You can test multiple features in a testsystem merging them, both in the "test" branch. And if you have multiple test systems, you can create multiple "test-branches" – Logicize

That's the issue ... having multiple "test systems". Nobody ever talks about that bottleneck. Also, testing multiple features in a single test branch is risky ... as you don't know what impact feature A will have on feature B. – Millstream

You are correct, deciding to have multiple test branches is risky and should considered carefully. The use is, if you have long term changes to be tested seperatly to short term bug fixes. Updating the Test systems frequently from Develop is important to do, after a release, or you may get in trouble later, when the larger features go live (like a new year release or something). But for long term changes, since they have usually larger impacts, to make an regression test also on the Release branch before go live. – Logicize

@ChristianMüller your approach is very interesting. I was just curious on knowing how do you handle database scripts considering the differences between feature branch and develop branch? – Waldack

@Felicity: That can be a little bit problematic, depending what you are using. I have two approaches for MS SQL Server. (1) With Database First Approach on SQL Server you can use DACPAC -> learn.microsoft.com/de-de/sql/relational-databases/… / (2) Alternate with code first you can use the migrations concept: learn.microsoft.com/de-de/ef/ef6/modeling/code-first/migrations – Logicize

Answer 6

I would not rely on manual testing alone. I would automate the testing of each feature branch with Jenkins. I setup a VMWare lab to run Jenkins tests on Linux and Windows for all browsers. It's truly an awesome cross browser, cross platform testing solution. I test functional/integration with Selenium Webdriver. My selenium tests run under Rspec. And I wrote them specially to be loaded by jRuby on Windows. I run traditional unit tests under Rspec and Javascript tests under Jasmine. I setup headless testing with Phantom JS.

Revive