What is Git Merging, Git Rebasing and Git Bisect and differences between git merge and git rebase
In this tutorial, we are going to learn about Git Merging and Git Rebasing, Rebasing is the process of moving or combining a sequence of commits to a new base commit. Unlike merging, rebasing flattens history; it transfers the completed work from one branch to another. Advocates of Git rebase like it because it simplifies their review process. The answer to the Git rebase vs. Git merge workflow question is –– “it depends”. At Perforce, we believe neither extreme is necessary. There are use cases for both, and it’s up to your team’s individual organization level whether you should rebase or merge.
This is also called as fast forward merge i.e., the commits coming from a branch are projected as the top most commits on the master.
- Repeat Step1 -6 from previous scenario.
To rebase test with master.
git checkout test git rebase master git checkout master git merge test
Rebasing is the process of moving or combining a sequence of commits to a new base commit. Rebasing is most useful and easily visualized in the context of a feature branching workflow.
- Git rebase is a command that allows developers to integrate changes from one branch to another.
Git merge is a command that allows you to merge branches from Git. Merging is a common practice for developers. Whether branches are created for testing, bug fixes, or other reasons, merging commits changes to another branch. It takes the contents of a source branch and integrates it with a target branch.
Git rebase compresses all the changes into a single “patch.” Then it integrates the patch onto the target branch. Unlike merging, rebasing flattens history. It transfers the completed work from one branch to another. In the process, unwanted history is eliminated. Advocates of Git rebase like it because it simplifies their review process.
Git rebase and merge both integrate changes from one branch into another. Where they differ is how it’s done. Git rebase moves a feature branch into a master. Git merge adds a new commit, preserving the history.
When you use Git merge, only the target branch is changed. The source branch history remains. Advocates of Git merge like it because it preserves the history of a branch.
Some developers believe you should always rebase. And others think that you should always merge. Each side has benefits.
- Streamlines a potentially complex history.
- Avoids merge commit “noise” in busy repos with busy branches.
- Cleans intermediate commits by making them a single commit, which can be helpful for DevOps teams.
- Simple and familiar.
- Preserves complete history and chronological order.
- Maintains the context of the branch.
The answer to the Git rebase vs. Git merge workflow question is –– “it depends.” At Perforce, we believe neither the “always merge” nor “always rebase” extreme is necessary. There are use cases for both.
- Rebasing privately affects only the individual (prior to work being pushed).
- Rebasing publicly impacts other people in the branch.
- Team policies are essential and supersede individual preferences.
- Keeping your entire history may be essential to meet regulatory and compliance needs.
If you’re working alone or on a small team, use rebase. If you’re working with a big team, use merge.
- Teams need to consider several questions when setting their Git rebase vs. merge policies. Because as it turns out, one workflow strategy is not better than the other. It is dependent on your team.
- Consider the level of rebase and Git competence across your organization. Determine the degree to which you value the simplicity of rebasing as compared to the traceability and history of merging.
Git Bisect we use to pick bad commit out of all good commits. Often developers do some mistakes. For them it is very difficult to pick that commit where mistake is there. They go with building all commits one by one to pick bad commit. But Git bisect made their lives easy.
- Git bisect divides all commits equally in to two parts (bisecting equally). Now instead of building each commit, they go with building both parts. Where ever bad commit is there, that part build will be failed.
- We do operation many times till we get bad commit. So Git bisect allows you to find a bad commit out of good commits. You don’t have to trace down the bad commit by hand.
- git-bisect will do that for you.