Git has become the de-facto standard for version control in software development. Developers should have a good understanding of Git. Very often though developers learn only a few simple commands and overlook the powerful abilities of Git that can make version control much more efficient. I would like to share my findings in lesser-known features that could take the developer’s daily workflow to the next level.
Recover deleted branches
Branch deletion removes only the reference to the blog. The actual cleaning is done by the garbage collector, which is usually not for days or weeks depending on your settings and version. A branch can be easily recreated once we figure out the commit hash was for the tip of it. We can use git reflog which tracks the movement of HEAD and grep to limit tracks.
Command will reveal the hash and the number of movements of when the deleted branch was checkout out.
Then we can get back to that branch in one line.
The command allows you to go back to a time that you need and recover a code that is gone now.
Move changes to a correct branch
We may have a situation when we accidentally committed code. We can use a “soft” reset in that case, undo the last commit and leave the changes available.
git stash
Move to the correct branch
git stash pop
git add .
git commit -m “my changes”;
Now changes will be on the correct branch. There is also an option to use cherry-pick for situations like that. I prefer soft reset because it can reset back more than one commit. We need to change the number after ~
Find a commit that breaks code
Git bisect performs a binary search between two given commits and then presents a specific commit’s details. One of the ways to use it is to be on the branch where the code has a problem. First, we invoke the bisect session and mark the current commit as a known problem commit.
git bisect bad
Next, find a commit hash where we know things were stable and indicate to bisect
Git will split the range of commits between good and bad in half and checkout the midpoint commit. Now we can run our specs and mark that commit as “good” or “bad” accordingly. We can repeat that process until we find one possible commit remaining. Note that as long as you have one good commit and one bad, the commits can be even years apart
Remove a file from git, but not file system
We can accidentally add a file to git that we don’t want to commit. Running git rm will remove a file from the staging area and our file system, which may not be what we want. We need to make sure we only remove the staged version and add the file to our .gitignore to avoid making the same mistake:
echo filename >> .gitignore
Avoid repeated mistakes with git hooks
It would be easy to avoid frequent mistakes by running certain checks or cleanup tasks at a defined stage of the git workflow. Hooks were exactly designed for scenarios like this. Every Git repository has a .git/hooks folder with a script for each hook. We can change or update these scripts as needed, and Git will execute corresponding when that events occur.
Below is an example hook to check branch names. Although there is no dedicated hook for the new branch creation event, we can use the pre-commit hook. We will be checking if the branch name is correct and exit with 0, otherwise we will print an error message and exit with 1. To get the current branch name we use this:
The branch name should start with feature, bug or chore, and only contain lowercase letters, digits, and some special symbols.
And the final hook code would look like this:
valid_branch_regex=”^(feature|bug|chore)\/[a-z0-9._-]+$”message=”The branch name should start with feature, bug or chore, and only contain lowercase letters, digits, and some special symbols. Please rename your branch to a valid name and try again.”if [[ ! $current_branch_name =~ $valid_branch_regex ]]
then
echo “$message”
exit 1
fiexit 0
Git has tons of commands, details, options, and is the very powerful tool that developers use every day. I hope that my findings will help other developers be a little more productive in Git commands.
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