My boss announced yesterday a new commit policies for checkins into the repository. This policies are valid for commits into head/trunk and branches.
A commit message must have the following items:
Reason (Bug ID,Project ID, or non functional change)
Name of the reviewer
After the commit we also have to create a change blog entry in our CMS.
I'm not a big fan of this commit policies, because I don't normally need a reviewer when I am doing new or experimental stuff in a non-productive-branch.
Do you have any commit policies do you have to follow?
I think it is a good idea to change the productive-branch only due to a Bug Report, but commits into the development branches should be less restrictive.
Commit early and commit often.
We actually use /trunk as development and tags to branch different releases. Only structural intrusive changes go in /branches.
We actively use tags for production and acceptation releases, so we can go back in time easily. Anything committed in the trunk should only have a message describing what the commit changed or added briefly.
I'm not a big fan of using the message space to link with Bug ID's it still requires a lookup for the ID in which case you could also look it up in the bug tracking software and close it there, which to me is about the same effort.
Not to say i dont like any svn integration:
- We use more goodness of automated nant scripts to make releases which branches them in /tags
- svn props actually store our version numbers :p.
- hook scripts for email notification and message logging (great for copy pasting release notes).
We have a number of policies, which are enforced via an in-house plug-in to Visual Studio. We check that code compiles and that unit tests have be run successfully. At the moment we also check code coverage and issue warnings for code which doesn't have enough tests. We also do various consistency checks and verify that an appropriate task is present in our change management system in order to provide traceability for all changes.
The advantage of tool support is great, as it is not really up to people to respect the policies, but obviously there's a drawback as well as these checks take time to run. However, with many developers it is hard to enforce standards without proper tool support.
A reviewer seems pointless for the reasons you mentioned, because not everything needs to be reviewed by others.
In the past the only commit policy we had (where I used to work) was to include a comment indicating what you changed and why, but that's more common sense than anything else.
A common commit policy is to associate a bug ID to the commit to trunk as a justification. Sometimes, version control and bug tracking systems are configured to enforce this policy.
Our commit policy sounds a bit like yours, only we don't enforce it on task branches (where a task branch is like a developer's sandbox for experimenting).
Our commit comments must include either a change control ID (new feature, enhancement) or an issue ID (bug fix). You must also include a brief explanation as to why you made this change; version control tracks the who, what, when and where.
My commit message include a short describtion what i have implemented or changed in the classes.
The bug number and additional describtions i put in the commentation above the new code. IDs inside the commit messages we put when we merge changes into a tagged branche.
Every night a automatic build checks the different features and products too get sure that the code base is stabil.
But in the end i think you can not have too many describtions for new or changed classes but too many policies you have to do before a commit. The name of the reviewer is something which i would not put into the commit message.
Think about that you sometimes have to undestand your code which you have implemented 2 years ago. And then you are happy about commit messages which are not like "Update after debugging".
We have branches for every released major version of the software that is still actively supported. Checking into any of these branches requires a bug ID - this is enforced by scmbug, which will not only check that the comment is prefixed by the bug ID, but will also look up this bug in the bug database, ensure it is assigned to the committer, and potentially check other criteria (e.g. that the "fix in branch" field is the branch being committed to).
One of the products has more potential to fail in embarrasing ways, and checkins to this require not just a bug ID but a code review as well. However, the criteria for the code reviewing is handled in our bug database - we have custom fields for this and the bug cannot be accepted and closed until it has been reviewed. To me this works from a conceptual level - it's probably better to check code that is believed to work into the repository un-reviewed, then reopen the bug and change it if necessary rather than hold off on committing until you're sure it is ready for release.
Other than that, there's no explicit policy for the trunk (though of course the general tenets of checking in often without breaking the build, including good descriptive commit messages, checking in units of work atomically still apply).
Related
I am studying how to use GitHub to collaborate with other people.
I have already set up Collaborators for one of my project and they have been able to download it.
But I don't know how to go for the next step. In other words, after they make their contribution; how are they supposed to upoad the result of their work, so that I can get it?
Yes indeed, by following the guides I have been able to make an update to a test project.
But everything is not quite clear yet.
I follow the process of creating-a-branch -> editing-something -> creating-a-pull-request -> merging-the-branch.
Then I delete the branch since it is no more needed. Apparently it works, but I can still see the deleted branch after, so it doesn't seem to be really deleted.
Starting July 2019, using GitHub Desktop, as part of its epic "branch pruning" and its 2.1.0 release, will prune those remote tracking branches for you.
Branches that have been merged and deleted on GitHub.com will now be pruned after two weeks.
See desktop/desktop issue 750:
We decided in taking a very conservative posture that we would only delete branches that aren't actively in use (hence the 14 days requirement) and don't have anything on them that's ahead of the default branch on GitHub. This combination, in addition to the branch being deleted on GitHub.com, seems relatively uncontroversial, but we're definitely going to listen to feedback we receive in the weeks and months after this ships to make sure it aligns with people's expectations and isn't overly aggressive.
Because we've taken an extremely conservative approach here, we don't intend to provide the ability to toggle it as a setting.
If you use a particularly branch frequently, this will never prune that branch, and it's restricted only to branches where there is no additional work that hasn't been merged into the default branch on GitHub.
In other words, we set this up intentionally such that users should never lose any work, which is our primary concern when deleting things. Hope that makes sense, and appreciate the feedback.
Based on my SO post I've been using Github as our VCS and with the help of the windows Github tool it's been great to handle those basic operations. Yet for merge like operations, I've to get back to Gitbash (SO Post) but thats ok.
So, the source code level VCS is in place. Now, we want to take a step
forward and use its simple issue-tracker to have "release control". For us,
this means being able to track each stable build (it can be a new
feature or bug fix, etc..) The idea is to create issues, tie them to a
milestone and use Github commit comments to close the issue and mark
it as a stable release/build. Where does tagging come in picture?
I've learned that we shud have a "development" branch for ongoing changes and periodically merged with the master (i.e. each stable build).
Is this the right way? We need to be able to go back to release / build 1.0 from 1.1 - sort of rollback just in case its required anytime in future (is this possible? how?) Is Github suffie or do we need to use some external tools as well?
Please share your experience and suggestions.
As I wait for other expert comments, I'd like to share a model that I've come across and seems great!
A successful Git branching model (SO Post)
To summarize, here is how I can address my basic needs (and scale it as and when required) -
Initially maintain two branches "master" and "development"
Master should always have a stable version and development has an ongoing source (might not be stable)
In the future, if we need to fix a bug after release, we can create a hotfix branch and when stable merge it with master/development
A good thing I found is that I can maintain stable releases in form of tags (i.e. new tag for each new version)
Eventually, master branch will be merged with development as we proceed with each stable version
There's a lot more that can be handled with the above model but I see my initial concerns addressed. Any better suggestions?
I struggled asking that question but here it is.
I am using source control since several years for multiple projects using different systems (svn, hg, git) and I learned how to improve my messages by following guidelines etc.
But as far as I can remember I never ever had a look at them afterwards.
So ... how do you profit from your own commit messages? When I need to go back because I smashed something and need a fresh start, I usually just go back to the latest "node" (where I started or merged a branch). Do I write those messages just for people monitoring the project who are curious what is going on?
Regards
You write them as an aid to your future self, and others on the team. To give you some background of when I have found them useful:
I used to work on a project where commit messages were invaluable - on more than one occasion I used them to track down code that was years old. On that project our bug tracking system was also integrated with our VCS (ClearCase). So when you checked in a change, it would record the bug number in the commit comments. This was very helpful to allow you to trace back exactly what was changed and why.
So to sum it up, although commit messages may seem pointless if you are just starting out (especially if you are the only one working on the project), they become invaluable once you have a successful product that is supported in production by multiple developers.
Update
Another useful feature of commit messages is that they require you to review and summarize the changes you just made. Even if I remember what I have changed, I will often do a quick diff of a file before checking it in. I will briefly read it all over again to make sure there are no typo's, that I changed everything I meant to, etc. This is a simple way to review your code for those small little bugs that would otherwise find their way into your code. Anyway, after doing this I have a clear picture of what changed, so I use this to write a concise summary of the change when checking in the file. This is a simple habit that helps increase code quality with little effort on your part.
"Send me a list of the things you did in the past two weeks" - Boss
Your messages are more for other users than yourself. Although I make sure to place good commit messages even on personal repos as well. Helps when you get sidetracked on a project and visit it months down the line to get a handle of the recent work done on a project.
One thing I've found is that the commit messages are a good way to keep myself from not committing often enough. If I can't put the changes into a short commit message I probably should have committed the changes earlier.
In the best case, a commit is bound to a work item in a feature/bug tracker. That way you will be able to easily see which feature/bug has been implemented/fixed. This is not only useful to know if a certain revision contains a feature or bug fix but also to easily create a release note.
What would be the point of a commit without a note to tell you what it is? It's like asking 'Why do books have titles on the sides?', or perhaps 'Why do books have indexes and page numbers?'. It seems to me that a source control log that didn't have a description for each change wouldn't be very useful.
Reasons you may need to refer to the commit message include
A bug has surfaced and you want to find when that part of the code was changed last
You decide to undo some changes and need to decide which revision to revert to
For either of these possibilities, without good commit messages, you would be left looking through the diffs for every single commit until you found what you were looking for in the code.
My co-workers and I are having an argument over the value and usage of Tags in release/SCM systems. We're looking to the StackOverflow community to put in their thoughts to help us resolve the issue.
One side claims that Tags are a valuable addition to release management. An example of their use: we do a Maven release, which makes a new Tag (call it 1.0) which is code snapshot used for this release. This Tag should be a READONLY branch. When a bug needs to be fixed we can make a copy of the Tag into a new Branch (call it 1.1). Bug fixes go there. These fixes may be merged back into Trunk so that the main dev branch gets the bug fixes. Finally, 1.1 is released and a Tag 1.1 is automatically created. This cycle continues. The main benefit here of the Tag is that if you ever need to re-release version 1.0 for any reason, you can just release the Tag 1.0 with the confidence that it's never been altered by anyone. Also, saying "Release Tag 1.0" is cleaner than saying "Release revision 1 of branch 1.0 which is the original 1.0 without the fixes".
The other side claims that Tags aren't providing any valuable benefit, especially in a system like Subversion with global revisions, which act like a Tag in CVS. Plus, Subversion only gives a warning when committing to a Tag; it doesn't actually stop it. Their method is developing in Trunk and upon release you'd make a Branch called 1.0. You'd continue bug fixes in Trunk and if you needed to re-release those bug fixes to production, you'd merge them into 1.0 Branch and re-release 1.0. At some point, perhaps after major fixes or features in Trunk, you'd release and make Branch 1.1. Cycle continues. If you ever need to release the original 1.0 version, you'd have to check out Branch 1.0 revision 1.
Clearly both methods work. I'd like to hear the community's thoughts on which method is preferred and why.
Edit: I'm a little worried that the "best" way depends on the underlying SCM system. Either settle on Subversion for answers or if possible keep it SCM agnostic.
From an SCM agnostic point of view, a tag is very different from a revision.
Both may be implemented in the same way, both represents a "time line", but their goal is different:
a tag represent an immutable state where all files are referenced by a unique id. It is a name representing many things but mainly a stable state, ...)
a revision represent a commit transaction (not all SCM have those, especially the old ones with a 'file-by-file approach'). All commits do not represent a "stable" state (as in "compile" or "execute" successfully). They are just a new element of the global history.
The problem with SVN is that revision, tag and branches are all implemented the same.
But I would still prefer the option where a tag is used as a "read-only" branch.
In my opinion tags are useful. There will be times at some point in the life of the project that you come across a bug or a change and you want to know if it was there in a previous release. There will be reasons to compare code from one release to another to measure efficiencies both in performance and actually the development of the code.
Sure, there is a chance you can screw it up, but it can always be undone. There really is no reason not to, and there are several reasons why it might be useful in the future. To me its a no-brainer.
I agree that you should also be using branches and doing your development there, but anytime you actually release something, make a tag out of it.
Yes, you want to use tags.
Think of a tag as just a label or a name for a particular revision. It is very helpful in my experience to tag important milestones in a project, whether it's for production release or even for interim QA releases. You often will want to go back in time and see the source code for a particular release.
If you branch upon release, you can always figure out which revision was released to production, but this is kind of a pain compared to just looking at a tag. If you don't use release branches then it will be easy to lose track of which revision was used to create a particular build.
The problem with svn is that it blurs the distinction between tags and branches. Anyone can always commit to a tag, so it's not guaranteed to be fixed/immutable. In other VCS like PVCS, a "tag" is unchangeable. You can adopt a team convention to prevent commits to tags, or even maybe use commit hooks to prevent commits to tags.
We use tags (labels) when creating new baselines. We do it once a week, but some teams do it even several times a day.
The point (for us) is always making sure the new baseline is stable: so it's not just a build, is a build that passes the entire testsuite, several hours of automated tests plus potentially manual exploratory ones too.
Then the baseline is used as starting point for all tasks during the next iteration: every new task is a new branch starting from the baseline, which is known to be stable so whatever is broken in the task should be easy to trace inside the task itself.
Normally we only put tags (labels) on the main branch (or trunk or master depending on your SCM flavour) which is the integration point for all the other branches.
When we release an official product we create a "release branch for it" so it will only receive fixes while new development stays on "main". Then these "maintenance branches" (hopefully only one or two at a time) can be tagged too.
I like to think about tags as "just a fancy name for a revision". I've always thought about them that way, and IIRC in mercurial they are just that. In subversion however, as you say, they indeed are (cheap) copies of trunk/* to tags/fancy-name/
Honestly, I'd combine the two strategies for optimal results: tag and branch upon release. Your tag is called 1.0.0, branch 1.0-MAINT. Bugfixes go into branches, and bugfix releases are tags again (1.0.1 may by a tag intended to alias 1.0-MAINT at a certain point.)
Do not forget however that tags and branches in subversion are actually the same thing: cheap copies. The only difference between them is the semantics you/your team attributes to them, so it pretty much boils down to getting people to agree on one particualr method and stick to that (might be enforced on the server, eg disallowing commits in tags/ except for release coordinators etc.)
The problem I see though with the second approach is: how are you going to make an easy distinction between software in the field if you re-release 1.0? That means that you may have a 1.0 and another 1.0 actually referring to a different code base... .
Immutable snapshots of a project's source code (and executable) are invaluable for doing testing of any kind, whether structured testing or field usage. For structured testing, you're going to be creating data that might be referenced months or years in the future. Anytime you revisit that data, Murphy's law says you'll need to know what code it comes from and unless you went to the trouble of citing a particular snapshot of the source code, it will be impossible to tell with confidence what source code corresponded to that test data.
I can't tell you how many times someone's come to me and said "This microcontroller code's not working, can you help?" and I ask them, "What version are you using?" and they say "I'm not sure" because they're not doing good release management (at the very least putting a sticker on the device, better to put versioning info in EEPROM that can be queried in realtime). >:(
In SVN, the technical difference between using a tag and tracking a revision is nil. I find myself minimizing tag use based on how SVN's implementation is simply a cheap copy and clutters up your "structure space".
The real difference comes when communicating a particular baseline to a large team of developers. Revision tracking brings an extra layer of abstraction that can become a source of errors. And as we're all aware, when you're dealing with 50+ developers, any source of error will become an area of confusion and wasted time. A verbose tag can eliminate that confusion and remove any doubt as to what a baseline's purpose is.
I'd combine both approaches. Whenever you make a release, tag it. Tags should never change, so the presence of a "1.0.0" tag is an indicator that you shouldn't be trying to release anything else as 1.0.0.
At the same time, when it came time to do 1.0.0, I'd put it onto a 1.0 branch. So the flow is: branch trunk to 1.0, tag this new 1.0 as 1.0.0, and deploy. Then bug fixes can be done on the 1.0 branch (to avoid getting mixed up with any 1.1-targetted development that may already be on trunk now) and merged into trunk. Each release of the fixed 1.0 is tagged as 1.0.x from the 1.0 branch. This is basically the approach we use at work with Perforce, and that's very similar indeed to Subversion. (Reading through the replies, I think it's virtually identical to Vincent's recommendation)
As far as the comment about tags being redundant because you have revision numbers--- that's largely true, except that tags also specify a scope: i.e. which files in the repository are covered by the tag. You can reasonably ask someone to look at /svn/proj1/tag/1.0.0 and they are immediately looking at a coherent workspace. If you ask them to look at revision X, they have to first look at revision X to see that it was changing (say) /svn/proj1/trunk/Makefile and hence deduce that /svn/proj1/trunk/#X is what they should be looking at. What happens if revision X touched files in proj1 and proj2? Which is of course evil, but strictly speaking you should be saying /svn/proj1/trunk/#X. And where is the list of revision numbers stored? How do we know that 1.0.0 is revision X? It should IMHO be possible to determine that just from the repository.
In systems like Git, tags and branches are still basically the same thing (just references to the object database), but the convention is that tag refs don't change, and branch refs do (and preferably with a specific constraint on how they change). Perforce also has "labels" which are ways of grouping a set of file revisions together independently of a changelist; which is essentially a tag, but more confusing: historically we've used changelist numbers (equivalent to Subversion revision numbers) qualified with the name of the branch they should be on to identify versions. The two are almost identical any way, so here I guess TMTOWTDI.
I've tried using source control for a couple projects but still don't really understand it. For these projects, we've used TortoiseSVN and have only had one line of revisions. (No trunk, branch, or any of that.) If there is a recommended way to set up source control systems, what are they? What are the reasons and benifits for setting it up that way? What is the underlying differences between the workings of a centralized and distributed source control system?
Think of source control as a giant "Undo" button for your source code. Every time you check in, you're adding a point to which you can roll back. Even if you don't use branching/merging, this feature alone can be very valuable.
Additionally, by having one 'authoritative' version of the source control, it becomes much easier to back up.
Centralized vs. distributed... the difference is really that in distributed, there isn't necessarily one 'authoritative' version of the source control, although in practice people usually still do have the master tree.
The big advantage to distributed source control is two-fold:
When you use distributed source control, you have the whole source tree on your local machine. You can commit, create branches, and work pretty much as though you were all alone, and then when you're ready to push up your changes, you can promote them from your machine to the master copy. If you're working "offline" a lot, this can be a huge benefit.
You don't have to ask anybody's permission to become a distributor of the source control. If person A is running the project, but person B and C want to make changes, and share those changes with each other, it becomes much easier with distributed source control.
I recommend checking out the following from Eric Sink:
http://www.ericsink.com/scm/source_control.html
Having some sort of revision control system in place is probably the most important tool a programmer has for reviewing code changes and understanding who did what to whom. Even for single person projects, it is invaluable to be able to diff current code against previous known working version to understand what might have gone wrong due to a change.
Here are two articles that are very helpful for understanding the basics. Beyond being informative, Sink's company sells a great source control product called Vault that is free for single users (I am not affiliated in any way with that company).
http://www.ericsink.com/scm/source_control.html
http://betterexplained.com/articles/a-visual-guide-to-version-control/
Vault info at www.vault.com.
Even if you don't branch, you may find it useful to use tags to mark releases.
Imagine that you rolled out a new version of your software yesterday and have started making major changes for the next version. A user calls you to report a serious bug in yesterday's release. You can't just fix it and copy over the changes from your development trunk because the changes you've just made the whole thing unstable.
If you had tagged the release, you could check out a working copy of it and use it to fix the bug.
Then, you might choose to create a branch at the tag and check the bug fix into it. That way, you can fix more bugs on that release while you continue to upgrade the trunk. You can also merge those fixes into the trunk so that they'll be present in the next release.
The common standard for setting up Subversion is to have three folders under the root of your repository: trunk, branches and tags. The trunk folder holds your current "main" line of development. For many shops and situations, this is all they ever use... just a single working repository of code.
The tags folder takes it one step further and allows you to "checkpoint" your code at certain points in time. For example, when you release a new build or sometimes even when you simply make a new build, you "tag" a copy into this folder. This just allows you to know exactly what your code looked like at that point in time.
The branches folder holds different kinds of branches that you might need in special situations. Sometimes a branch is a place to work on experimental feature or features that might take a long time to get stable (therefore you don't want to introduce them into your main line just yet). Other times, a branch might represent the "production" copy of your code which can be edited and deployed independently from your main line of code which contains changes intended for a future release.
Anyway, this is just one aspect of how to set up your system, but I think giving some thought to this structure is important.