Merging Your Changes

You've successfully navigated the pull request process! Your changes have been reviewed, feedback has been addressed, and your colleagues have given their approval. Now comes the exciting part: merging your work into the main branch of the project. This is where your contributions officially become a part of the codebase.

The merge process integrates the commits from your feature branch into the target branch (often 'main' or 'master'). GitHub provides a user-friendly interface for this, making it a seamless experience. When you click the 'Merge pull request' button on your pull request page, GitHub intelligently analyzes the history of both branches and attempts to combine them.

graph LR
    A[Feature Branch] --> C{Merge Pull Request};
    B[Target Branch (e.g., main)] --> C;
    C --> D[Integrated Codebase];

There are a few common ways GitHub can merge your changes, depending on the complexity and history of your branches. The most common are 'Merge commit' and 'Squash and merge'.

Merge Commit

This is the default and most straightforward merge strategy. A new commit is created on the target branch that has two parents: the last commit on the target branch and the last commit on your feature branch. This preserves the entire commit history of your feature branch, showing exactly what happened step-by-step. It's excellent for understanding the evolution of features.

graph TD
    A[Target Branch Commit 1] --> B[Target Branch Commit 2];
    C[Feature Branch Commit 1] --> D[Feature Branch Commit 2];
    B --> E(Merge Commit);
    D --> E;

Squash and Merge

Instead of creating a merge commit and preserving all individual commits from your feature branch, 'Squash and merge' takes all the changes from your feature branch and applies them as a single new commit on the target branch. This keeps the history of the target branch cleaner, especially for small, self-contained changes, but you lose the granular commit history of the feature branch.

graph TD
    A[Target Branch Commit 1] --> B[Target Branch Commit 2];
    C[Feature Branch Commit 1] --> D[Feature Branch Commit 2];
    D -- Squashed --> E(Single New Commit on Target Branch);
    B --> E;