I am new to version control. I often hear these words Merging and Branching. I also see different developers working in different branches.
Can someone explain the flow on this. What is the difference between Merging and Branching. When to go for Merging and Branching
Branching is about isolating a development effort in a specific history, parallel to the main one.
See "When should you branch?": you branch when you cannot commit on the current branch (because it would break the work of your colleagues)
Merging is about reconciling two different branches.
You merge when you want to take into account in your branch the changes of the other branch you need to merge.
The workflow depends on the tools.
SVN offers either merge-based development or trunk-based development.
Tools with easier branching capabilities (like Git for instance) offer a workflow based on the various development lifecycle steps:
In the concept of git,
Branch is just a pointer to a commit, and will be advanced to the new commit when you make new commit to that branch.
Git has 2 types of branches: local and remote.
git can merge any single commit, not only the head of a branch.
I take the most simple merging workflow as an example.
2 developers are working on a project.
They are working independently based on the same version.
They share the master (main) branch via a server when they complete.
The first developer commit changes and push to the remote branch first. The second developer then synchronizes the changes by pulling changes made by the first developer.
A merge commit will be automatically created.
Related
Github has the option to allow a PR to be squashed when merged ("Squash and Merge")
Is there anyway I can configure the branch so it only allows the "Squash and Merge" option?
My scenario is this
we have a develop branch, that feature requests are pushed to
sometimes developers will forget to choose "Squash and Merge" and will commit their feature branch, with 10-20 tiny commits to the develop branch.
These changes eventually get merged to master, and feature history becomes hard to read
I have looked in hooks in branch protection rules, but didn't see any such option
Unfortunately the option to change what type of PR merge is available on Github is set on a per repo basis. Since PRs are a github thing, not a git thing, I can't think of a way that you'd be able to do anything with githooks either.
I don't see a great option for your workflow as long as you require the intermediate develop branch that eventually gets merged into master. Workflows that have multiple layers of PRs get messy on Github. The one real option would be that you require squash to merge on Github PRs and then the regular merge from develop to master happens outside a PR (could be local on a machine or via a Github action potentially).
But, your best option if this is really a big problem may be to modify your workflow. One common workflow would be that master is the development branch. Then when it is time for a release a release branch or tag, depending on your needs, is created from master. The you will have no issue turning on the repo wide requirement for squashing.
Setting up new projects and branch designs in TFS 2015. This detail may be significant - I'm using it for PowerBuilder projects, not .NET - VS2015 is used to set up branches and perform merges, the files themselves will be checked in and out in PowerBuilder. Far as I can see that shouldn't make a difference, but mentioning it in case I've missed something
Using the following sample layout:
Prod branches to/from Mod, down to Dev. New CO projects branch from Prod (so they always start with a fresh set of the latest live code), then merged (via baseless merge) to the DEV branch, and re-parented once the connection is set up. That way the users wouldn't have to remember to do a baseless merge; Dev will become the default merge target
Merges would them go back up from Dev to Mod, then back to Prod
The issue is that as a test, I tried the baseless merge after the branch, expecting no files to be merged, as nothing has changed yet in any branch. But the merge from the CO branch to Dev merged ALL files. Not an issue now since there's no changes in place, but would be quite a problem once several projects have been merged to DEV.
After that merge, I made a small change in the project and tried a merge; only the one changed file merged.
My best guess is that since the new CO branch was created after the Dev Branch, it was seen as everything in it is newer than the Dev branch, so it rolled over everything. Not sure how it would treat changes in Dev not seen in the Prod branch yet, haven't tested that scenario. It SHOULD at the very least tell me there's changes that I need to merge, but I fear it might just roll over them with the "new" files in the CO branch.
The question is, how can/do I tell the system that this new branch is "not newer" than the Dev branch? Does indeed the fact that these are PowerBuilder files somehow limit the ability of TFS of recognizing versioning in some way?
Or even more simply, is the branch layout I'm trying not the best method?
EDIT - here's the structure I'm currently using for my .NET projects - I was trying to use the layout above instead for the new code.
It uses the "Main" branch suggested below in the comments, but since I'm pulling "CO Branches" from Dev, I get code currently being tested, and not pristine Prod code. I'm assuming trying to branch and re-parent from Prod in this layout would result in the same scenario.
So is this the better way to go after all?
You may have a Main branch, which is the junction branch between development and release branches, representing a stable snapshot of the product.
You can branch from Main to Dev, Mod and Prod, when the work on Dev branch finished, merge from Dev to Main, when you want to release the product, merge from Main to Prod. So when you want to branch from the latest live code, you can branch from Main. In this way, you can merge from CO to Main, then Main to Dev or Main to Prod. All changesets will be reserved.
Caveat: I am fairly new to both git and GitHub.
So, in my current setup, my team uses git flow Hotfixes (usually started and finished by a graphical tool such as GitKraken or IntelliJ) to make changes that have to be merged into two branches and pushed upstream in both. So for example the flow would be:
Pull latest from master
Start hotfix
Commit changes
Merge hotfix branch into both master and develop and push both upstream
We're now looking at moving our code into GitHub and would like to start using Pull Requests, for a couple of reasons:
CI hooks to run tests and stuff
a place to put code-specific comments not directly related to the underlying "issue"
avoiding the need for everyone to constantly be pulling the latest master/develop to their local machine so that they can merge changes
But in the case of Hotfixes, I'm not sure what to do because I'm merging into two branches but it really is one "action" so manually creating two pull requests seems weird, particularly since step 4) in our current flow is a single click.
Is there a smart way of handling this? My ideal case would be that pushing the Merge button on the Pull Request would just merge into both, but that doesn't seem to be an available option.
As you mentioned, a Pull Request has only one target branch, so you won't be able to push the hotfix to both master and develop by merging one Pull Request.
I'm also surprised you mention your step #4 - merging the hotfix branch to both master and develop and push upstream - is one action. While there's a high chance the merge from hotfix to master won't run into merge conflicts, I can't say the same for the merge from hotfix to develop since it could have been worked on since the last deployment to production.
My recommendation would then be the following:
Create one PR from hotfix to master and have someone review it to validate the fix
Once it's merged into master, create another PR from hotfix to develop and see if you run into merge conflicts
If that's the case, resolve the merge conflicts so the PR ends up in a state to be merged, and have someone review the PR
If there's no merge conflicts, then have someone review the PR
An alternative solution, if you really want to go down the automated path, would be to leverage both GitHub webhooks and API.
The webhook would allow you to be notified when a PR is merged. You could inspect the payload to make sure that the base branch starts with hotfix/ and the target branch is master. You could then react to that event by using the API to create a new PR from the same hotfix branch to develop.
It will involve some development, and the effort might not be worth since creating a PR via the UI is still quite easy and quick.
When should one branch/tag in Mercurial (hg), both at the local repo level and at the centralized/originating repo (that you hg clone)? When should you merge (again at the local level and in the central repo)?
I come from a SVN background where branches were used for new features ("feature branches"), as well as "release branches". In the case of feature branches, a developer would create a branch if he/she knew a project was going to span multiple sprints/releases. The feature branch would then be merged back in once the developer was certain they'd be releasing the new feature during the given sprint. The release branch would then be created and deployed to QA and a staging environemnt for QAT/UAT testing respectively. Any bugs that arose during testing would be committed directly to the release branch. When the release branch was finally ready to be released, it would be tagged (for archival/record-keeping purposes) and then finally, after the release branch was deployed live, it would be merged back with trunk.
How does this process change with a DVCS such as hg?
Branching|merging policy can does not differ at all. These processes just give less headache in Mercurial (you will not be a victim of "Refactoring Hell" with a minimal level of accuracy, unfamous Tree Conflicts are also history) - DVCS vs CVCS will change almost nothing here, Mercurial give you just more freedom: branch when|if you want
A common scenario when using source control is to have a development branch along with versioned release branches. We use CVS, with HEAD as the development branch, and a branch named e.g. release-6-2 for the current release of a product.
Development of new features go into the development branch only, but bug fixes sometimes have to be checked into both the development branch and the current release branch. This can get quite tedious at times, so I am looking for practical ways to accomplish this.
When a file to be commited is in synch on the two branches, I am in particular looking for a quick "commit to these branches" solution.
(We use CVS as our source control system, so any CVS-specific answers are nice. However, it is also interesting to see whether other source control systems can offer a better way.
On the client side we use Eclipse, so Eclipse solutions are good. But if you have a non-Eclipse solution, that is fine too.)
Apply your fix to the oldest release branch required. Then merge the change to the next release branch and so on until you merge from the last release branch to the HEAD.
Say the oldest version of your product is 1.0 and you also have 1.1 and 1.5 releases. New features for the next release are being added to the HEAD. If a bug is found in 1.0, you apply the fix to the 1.0 branch. Merge from 1.0 to the 1.1 branch. Merge from 1.1 to the 1.5 branch, and finally merge from the 1.5 branch to the HEAD.
Merging from branch to branch is better than applying the fix manually to each branch.
With CVS you have to mannually keep track of what versions are merged, so that you do not include the same revisions when you do your next merge.
If you change to use Subversion, merging from branch to branch is easier. Eclipse's subversion tool will keep track of what revisions you have previously merged, greatly simplifying the task of doing repeated merges between two branches.
Changing to Subversion from CVS is easy(ish). You won't be the first to have made such a move.
Like awalshe said, it's better to merge between branches. To cherry-pick a merge, the method described in Pragmatic Version Control using CVS is very good:
In the branch - tag (PRE_FOO) before the change, make the changes and commit, tag after the change (POST_FOO). Then, in trunk, merge using the tags:
cvs up -j PRE_FOO -j POST_FOO
Merging between branches is much easier and safer in SVN, and it's trivial to convert your entire CVS history to SVN - see cvs2svn. You should use either SVN 1.5, or - with earlier SVN versions - svnmerge.