Inverse `cherry-pick` operation - babeljs

I have a repository with the file content. In a branch, I submit some commit to this new feature. Somewhen, I submit some wrong commits and continue my work submitting others, now correct, commits. How can I `cherry-pick` this commit out?
I tried to :
checkout to the local master branch (git checkout master). The previous branch commits remain, as you can see by git log);
checkout a new branch (git checkout -b new-branch)
Cherry-pick specific commits (git cherry-pick commit_sha)

You need git rebase, which allows (amongst many other features) selectively applying a set of commits from one branch into another.
I find Tortoise Git's interactive rebase tool is quite easy to understand, if you are in Windows are enjoy using the mouse.
In any other case, I'd still recommend using an external tool such as the git-interactive-rebase-tool command line utility.

Related

How to keep a GitHub fork up to date without a merge commit or using CLI?

The normal GitHub flow to contribute to a repo is to create a fork of the upstream, clone a local copy where you make changes, then push back up to your fork and then create a PR to have your changes merged into upstream.
But if upstream changes after that, how do you update your fork without creating a merge commit (and also without using the git CLI)?
I already know how to do this in a way that will create a merge commit or which depend on the git command line interface. This question is specifically about using the GitHub.com website or GitHub Desktop application only (no CLI).
Since this is a very common workflow it seems like there should be some simple way to do it using the GitHub GUI.
To reiterate: any answers that use the CLI or create a merge commit (e.g. this way) will not be answering this question since I'm explicitly looking for a non-CLI solution.
without a merge commit or using CLI?
Not directly with GitHub web UI alone, since it would involve rebasing your PR branch on top of upstream/master
So in short: no.
But in less short... maybe, if you really want to try it.
Rebasing through GitHub web UI is actually possible, since Sept. 2016, ...
if you are the maintainer of the original repo, wanting to integrate a PR branch
if none of the replayed commit introduces a conflict
(This differs from GitHub Desktop, which, since June 5th 2019 does support rebasing. But that is a frontend to Git CLI, like other tools provide. For example GitKraken and interactive rebase)
So a convoluted workaround would be:
to fetch, then push upstream/master to the master branch of your own fork (a CLI operation, but more on that below)
change the base branch of your current PR to master (so a PR within the same repository: your own fork), provided you haven't pushed to master.
Meaning: master in your fork represents the updated upstream/master, with upstream being the original repository that you have forked.
Since you are the owner of that repository (your fork), GitHub can then show you if you can rebase said branch to the base branch of the PR (master), but only if there is no conflict.
finally, change the base branch again, to <originalRepo>/master (which is the intended target of your PR)
The very first step is typically done through command line, but... there might be a trick to do it (update upstream master in your fork) through web UI: see "Quick Tip: Sync a Fork with the Original via GitHub’s Web UI" by Bruno Skvorc
In short, it involves:
creating a new branch from your current master (which would be at upstream/master at the time you forked the original repository)
Making a PR with that new branch and <originalRepo/master>
doing a base switch before creating the PR
That is the step which artificially forces upstream/master to be refreshed
You can the create and merge it with the “Merge Pull Request” button (and “Confirm Merge” afterwards): the merge will be trivial: no merge commit.
The end result is: your own master branch (in your fork) updated with upstream/master (the master branch of the original repository)!
You can then resume the steps I describe above, and change the base of your current PR to your own (now refreshed) master branch, and see if you can rebase it!
This is feasible with GitHub Desktop since version 1.0.7 considering the following:
If the current branch does not have any commits ahead upstream (the original repo of the fork), the new commits can be pulled without creating a new merge commit
In GitHub Desktop:
Clone your repository from File > Clone Repository
Fetch origin, which will automatically fetch the upstream as well
Go to Branches by clicking on where it says Current Branch
Click on Choose a branch to merge into <branch> at the bottom
Search for upstream/<branch>, then click Merge upstream/<branch> into <branch>
Push to origin, et voilà!
Otherwise, ff the current branch has commits ahead of the fork, then of course one has to create a merge commit or rebase and force push. For rebasing which might be more preferable, do the following:
In GItHub Desktop, go to Branch from menu, then Rebase Current Branch
Search for upstream/<branch>, then click Start Rebase
Solve any conflicts that have occurred from the rebase
Force push to origin. You will get a warning for this for obvious reasons.
For avoiding force-pushing to your work when your current branch is both ahead and behind its upstream counterpart, either create a new merge commit or:
Make a new branch based with all your changes
If needed, reset the original branch to its original state (before it diverged from the original repo)
Perform the steps from the first scenario and merge your changes into your branch.
And yes, it seems that pulling via the GitHub website from the original repo without creating a pull request and merge commit is not possible at this moment.
Demo GIF for first scenario: https://imgur.com/a/8wci2yf
Some GitHub issues related to this:
Add an upstream to forked repositories
multi-remote support in Desktop
Update
Note: Non-CLI based approach that might help:
Is there a way to make GitHub Desktop rebase a branch against master?
The only key here is doing a rebase, so the above answer should help.
CLI way (which is easier and using git, so it should be more comprehensive by default)
There are some practices that you should use to avoid this.
Don't work on the master branch in your fork.
$ git clone <your fork>
$ git checkout -b feature_branch
You can work in your feature_branch and then raise a Pull Request.
Once your changes are merged in the upstream master, you can pull from upstream to your origin. Since the master on upstream will have your commits sitting neatly on top of it, there won't be a merge commit.
$ git checkout master
$ git pull upstream master
$ git push origin master
In the case, where the maintainer has diverged from the master that you have in your fork, that is, it's not linear any more, you need to pull a fresh copy of it. That should not be a problem as your changes are already in the upstream.
If the master in upstream has moved ahead while you were working on your PR, then you can rebase on you feature_branch.
$ git checkout master
$ git pull upstream master
$ git push origin master
$ git checkout feature_branch
$ git rebase master
Please refer to this document for detailed reference: Fork and pull request workflow

Need guidance in Github merge

I am new to managing code revisions and need guidance on how to merge to code sets. I have a MASTER branch with my latest UI and I have a branch called "Feature-A" with lots of Django additions + template additions to the previous UI files.
Since I am new to Github, I want to take the safest approach incase I need to revert mistakes. Should I make a new brach of master and merge Feature-A into that branch or should I merge Feature-A directly into the MASTER?
Since you're new, I would say the best approach would be to create another branch (clone of master branch) and then merge feature A into that, and see if it works. If not, keep testing feature A to make it compatible. If it works, great! Just remove that extra branch and merge feature A into the master.
I.e.,
git checkout master
Then, create a new branch (git checkout -b 'featuretest')
Now, git branch shows
* master
* featureA
* featuretest
Then, do git checkout featuretest, and git merge featureA to merge it.
If the feature works, great! Remove the branch (git checkout master; git branch -d featuretest)
and do it for real (git merge featureA)
If the feature doesn't work, go back to the feature branch (git checkout feature) and keep testing.

How should I structure my git-svn workflow to avoid "revision1 is merged into revision2, but does not have git-svn metadata"

I am using git-svn in my workplace since our current version control server is subversion and switching completely to git does not seem to be on the horizon for now (*cry*)
My workflow is as follows
I have the following branches
master tracks remotes/trunk
local/0.4 tracks remotes/0.4
work is my development branch for the master branch
work-0.4 is my development branch for the local/0.4 branch
I work in my work branches, then I merge to master and local/0.4 using
git merge --no-ff <branchname>
After that I check in to svn via
git svn dcommit
and I use
svn.pushmergeinfo=true
to update the svn:mergeinfo properties so my colleagues won't get angry with me messing up that metadata for them :)
However, I just had the following problem which stumps me.
I had done two commits on the work-0.4 branch, then I merged these to my local/0.4 branch with git merge --no-ff work-0.4. After this, I did git svn dcommit and recieved the following message
Committing to https://svn-server ...
e138050f6ebd2f2ca99cbefc5e48acae412e1f86 is merged into revision f5f2345e8e5fc64
20423bdc00397b5853b3759c4, but does not have git-svn metadata. Either dcommit the
branch or use a local cherry-pick, FF merge, or rebase instead of
an explicit merge commit.
After some rebasing and reset'ing of branches I managed to push everything to svn, but my solution entailed doing a rebase of my local/0.4 branch to the work-0.4 branch which in turn meant that I did not get to squash my two git-commits into one svn-commit :/
I feel that I'm probably doing something wrong with my workflow here, and it might be related to svn.pushmergeinfo. The docs for svn.pushmergeinfo says
config key: svn.pushmergeinfo
+
This option will cause git-svn to attempt to automatically populate the
svn:mergeinfo property in the SVN repository when possible. Currently, this can
only be done when dcommitting non-fast-forward merges where all parents but the
first have already been pushed into SVN.
and to be honest, I'm not quite sure that I understand that correctly? Am I doing something weird here that makes svn.pushmergeinfo not work correctly? How should I structure my workflow to optimally work with git-svn correctly (setting proper mergeinfos etc)?

looking for ideal git-svn workflow

The company that I'm working is working with SVN but I would like to start working with git to take advantage of the light branching and stashing features (disclaimer, I'm pretty new to git). I've started with git-svn and I'm trying to figure out the ideal git-svn workflow for what I'm trying to do (and suggestions if what I'm trying to do needs tweaking).
I've read through git svn workflow - feature branches and merge and a few other posts but its still not clear how I should approach it.
How I plan to work:
I plan on having my master branch be clean from development and only used for merging/rebase/dcommit.
I would like break apart each new feature/bug into separate git branches so they can be worked on independently. Meaning, I can work on one feature for a few hours, then put it aside and work on the next issue. When I was in SVN it was a problem when I had two different features/bugs in one file because when it came time to commit, I would remember that it had both changes and temporarily take out what I didn't want to commit now - a pain.
And the are some features which are while I might want to work on now, will not be added to the main repo for some time.
After a feature is ready to be shared/tested in the main repo, I'll merge/rebase into my master branch and then dcommit to the svn-repo. I only want to have one SVN commit message for each dcommit - I want to be committing in more often with comments more specific to me and then dcommit to svn with a message for the rest of the team. I assume for this I'll either be using a git merge --squash or a git rebase --interactive for this.
The basic git flow I've envisioned is like this:
// it begins...
git svn clone <repo>
//
git checkout -b feature 1
// work commit, work commit
//
git checkout -b bug-123
// work commit, work commit
// bug-123 finished - ready to send back
// got back to master for step 5
git checkout master
// get whatever changes other devs did
git svn rebase
//
git checkout bug-123
// rebase branch so I have fewer smaller changes. not sure here..
git rebase master || git svn rebase
// Assuming I'm doing a FF rebase so my commits are just addons to the current repo
// I don't know if I rebase the master or svn repo or it doesn't matter.
// need to get my changes back to master to send off
git checkout master
// add my changes to master
git rebase bug-123 (--interactive?) || git merge --squash bug-123
// do I add a new commit message here?
// push my changes back out to the team
git dcommit
So there are a few questions:
How should I get the changes into the branch I want to commit - by rebasing the master or the svn branch
how do I get the changes back into the main branch - rebase or merge - remember, I want only one commit for each commit - unless this is going to complicate things - I really would prefer to keep my git commits separate from the SVN commits because I might start something - it's half-working, and want to commit it so I could try something else - but I don't want to commit these broken steps.
would it make sense to dcommit directly from the working branch (eg bug-123)?
how do I get the changes from bug-123 back now into feature-1? I'm assuming I'll do it via the SVN repo - meaning the changes that I added will get merged in when I do the rebase when it's time to add feature-1 to the repo - but maybe not.
I'm no expert, but these are the experiences I've made (related answer).
I think it doesn't matter. The important thing is that you rebase the latest changes from SVN into the branch you are going to dcommit from.
Let other branches receive the changes through SVN. If you want a single SVN commit from a series of git commits, squash them together first.
I think this doesn't matter either. You're going to rebase the latest changes from SVN, and need to get them linearly in front of your Git commits. If you do git svn rebase in master, and then rebase master into a feature branch, or the other way around is same-same. Afterwards you probably want to delete the branch, as it has done its work (as per SVN restrictions, you're not allowed to merge again).
Always let changes flow into other branches and repos through SVN rebasing.
Just try it out and try to get the most simple/practical workflow for you and your team. Try to keep branches short-lived (SVN won't get any notion of them anyway), and remember that the commits must always be linearized at the top of your log before you dcommit back.

How to develop on a branch in HG?

I would like to do some experimental work in a hg project. So I would like to create branch, commit to it. And if the experiment works, I can merge it back to main branch.
In git, I can do
$ git branch experimental
$ git checkout experimental
(edit file)
$ git commit -a
$ git checkout master
I've read A Guide to Branching in Mercurial. It said hg branch feature. But what is next?
I don't follow.
$ hg branch experimental
(edit file)
$ hg commit
$ hg update default
First note that git branch is different from hg branch. Branches created with hg branch are permanent and live in a global name space, whereas branches made with git branch are transient. The nearest equivalent of git branch is hg bookmark: bookmarks can be renamed and deleted and behave more like Git-branches.
I've recently written a guide for Mercurial bookmarks. Compare this with the named branch guide. Both guides contain worked examples of how to use (named) branches in Mercurial for keeping track of the development. It shows how to merge branches and how to close them or delete the bookmark when you are done.
If it's not a big feature (i.e. the branch doesn't have to have a name), it's quite simple.
Let's say your repository is at changeset X. You work on the feature as much as you like, commit, commit, commit and if you're happy with the result, continue as if you knew it would work all along. ;) If you aren't happy, do a hg update X and continue development from there. All the work you did on your experiment will become an anonymous branch.
Strangely enough, it appears that Git doesn't provide such a way to work with anonymous branches which is what might be confusing you.