How to Check If a Branch Has Been Merged into Master?

When working with Git, it's common to create and merge branches as part of your development workflow. However, it's essential to ensure that your branches are merged into the main branch (often master or main) to keep the codebase up-to-date and avoid redundant work. This article will explore several methods to determine if a branch has already been merged into the master branch.

Why Check if a Branch Has Been Merged?

• Avoid Redundancy: Ensure that work is not duplicated and that branches do not contain changes already integrated into the master branch.
• Maintain Code Integrity: Keep the master branch clean and up-to-date with all relevant changes.
• Facilitate Collaboration: Help team members know the status of branches and avoid conflicts.

Approach 1: Using git branch --merged

Step 1: First Checkout into the master branch using the command,

  git checkout master

Step 2: Use the git branch --merged command to list all branches that have been merged into the current branch.

git branch --merged

Approach 2: Using git log

Step 1: First Checkout into master branch using the command,

  git checkout master

Step 2: Use the git log command to see if commits from your branch are in the master branch's history.

git log

Approach 3: Using git merge-base

Step 1: Use the git merge-base command to find the common ancestor of the two branches.

git merge-base master your-branch-name

Step 2: Use the git rev-parse command to get the SHA of the branch tip.

git rev-parse your-branch-name

Approach 4: Using Git hosting services (like GitHub or GitLab)

Go to the Git hosting service you are using, In the section Pull Requests(GitHub) or Merge Requests(GitLab) check the status of your Merge or Pull Request.