Introduction

In collaborative software development, especially using Git-based version-control systems, the terms "pull request" and "push request" might seem interchangeable or confusing to newcomers. However, they serve significantly different purposes in the workflow of Git. In this article, we will delve into why it's called a "pull request" and not a "push request," exploring the mechanics of Git operations, the philosophy behind these actions, and the practical implications in team collaborations.

Understanding Git Basics

Before diving into pull vs. push terminologies, let's review some foundational concepts in Git:

• Repository (Repo): A centralized space where project files, including the version history, reside.
• Branch: A separate line of development within a repository.
• Commit: A snapshot of changes made to the codebase.
• Push: Updating the remote repository with commits from a local branch.
• Pull: Fetching and merging changes from a remote branch into a local branch.

The Concept of a Pull Request

What is a Pull Request?

A pull request is a formal request to merge code from one branch into another, often from a feature branch into the main branch of a repository. It's a collaborative process that involves several steps, such as code review, discussion, testing, and eventually, merging.

Why the Name "Pull Request"?

The term "pull request" originates from the fact that the repository owners or maintainers need to "pull" changes from your fork or branch into their main repository. You are essentially requesting the maintainers to review and pull your changes into their codebase.

Technical Explanation

To understand better why it's not called a "push request," let's explore the life cycle of both a pull and a push command.

Life Cycle of a Pull Request

1. Development: A developer creates a new branch and implements a feature.
2. Push: The feature branch is pushed to the remote Git repository.
3. Pull Request Creation: A developer requests to merge this feature branch with the main branch. The request is usually made on a platform like GitHub, GitLab, or Bitbucket.
4. Code Review: Other developers and project maintainers review the proposed changes.
5. Discussion and Iteration: Feedback might be provided, leading to more commits being pushed if necessary.
6. Merging: Once approved, the maintainer pulls the changes into the main branch.

Why Not "Push Request"?

• Centralized Authority: In most development workflows, the "main" branch has controlled access. A "push request" would imply that anyone could unilaterally push changes, which can lead to conflicts, broken builds, or security issues.
• Collaborative Review Process: A "pull request" system encourages collaboration and review before merging changes. It aligns well with code quality best practices by ensuring more eyes on the code.
• Git Philosophy: The decentralized nature of Git supports distributed workflows where contributions are pooled by maintaining a clean history and a stable main branch.

Examples

Example Workflow

1. Create a Feature: `git checkout -b feature-branch`
2. Make Changes: Modify files and `git add`, then `git commit` changes.
3. Push Feature Branch: `git push origin feature-branch`
4. Open a Pull Request: Use a web-based Git platform to propose merging `feature-branch` into `main`.
5. Review: Team members can add comments, request changes, or approve.
6. Continue Development: Apply feedback and continue to push until approval.
7. Merge: Once approved, merge the branch.