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Git magic - Make commits disappear

So fellas, it's been a while since I wrote and I hope this article is of help to whoever reads this. 

Let's start with bit of an introduction. Until my previous employment, there wasn't much guideline on how we write Github's commit message. One single feature could have n number of commits and it doesn't bother the repository. 

Now, am part of @webex's webex-js-sdk team where committing guidelines are very strict and having a bit more deep knowledge of git commands has become essential. This made me explore git commands on regular basis. So I thought why keep them to myself while I can share them.

It was my first ever PR and my changes were approved except for a few minor changes. I honestly didn't know how to make changes to existing commit and now, I had two choices. 

  1. Create a new branch from master and re-do the work manually
  2. Do some git magic and make the current branch work well. 
If it were old times, I'd have gone with option 1. It's very simple. However in this case, the PR was approved already. I wasn't ready to go over the approval once again. Therefore, I went in search of how to do the magic. 

 * Please read this post fully before executing any command. My scenario might not be same as yours.

I wanted something like git revert that doesn't add a new commit. So this is when I found my first ever weapon. 
git reset --hard

This command simply rolls back to one of the commits in the history making all commits from that one to the most recent disappear. 

So, the steps goes as,
  1. Backup your changes
  2. Do git log
  3. Scroll down to the commit until which you want to remove the history.
  4. Copy it's commit hash and execute the following command -> git reset --hard <copied_commit_hash>
  5. For instance, git reset --hard 54ace3456ka235rtyc90
This will place your head at the mentioned commit hash. Now you can manually paste your changes in the respective files either from your backup or from git GUI (github, bitbucket, gitlab etc.,) and commit it. Once done you could do a force push as indicated here -> git push --force.

Such a nasty way to update a commit right? I couldn't agree more. But this helps in cases when you mess up rebase and a lot of commit from upstream/master shows up in your commit history. 

If this is not a recommended way, then what is? Please head over to my next article -> Git magic - commit amend.


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