Mastering the Art of Pull Requests: An Expert‘s Guide

Pull requests are a cornerstone of modern collaborative software development, yet many developers struggle with using them effectively. In this comprehensive guide, we‘ll dive deep into the world of pull requests, exploring technical best practices, real-world use cases, and the etiquette that makes for a harmonious development team.

As a seasoned full-stack developer with over a decade of experience working on diverse projects, I‘ve seen firsthand how mastering the art of the pull request can supercharge your development workflow and take your team‘s collaboration to the next level. So, whether you‘re a pull request pro or just getting started, read on to level up your skills!

Why Pull Requests Matter

Before we get into the nitty-gritty of creating and managing pull requests, let‘s take a step back and examine why they‘ve become such an essential part of the modern developer‘s toolkit.

At their core, pull requests are all about enabling asynchronous code review and collaboration. In today‘s fast-paced, distributed development world, it‘s rare for an entire team to be in the same place at the same time, let alone working on the same schedule. Pull requests bridge this gap by providing a structured way for developers to propose, discuss, and iterate on code changes, regardless of their location or time zone.

But the benefits of pull requests go beyond just enabling remote work. By formalizing the code review process and creating a record of changes and discussions, pull requests also:

• Improve code quality by catching bugs and design issues early
• Promote knowledge sharing and learning within the team
• Provide a clear audit trail for changes to the codebase
• Facilitate asynchronous collaboration and decision-making

And the proof is in the pudding. According to recent industry surveys:

• Over 87% of developers use pull requests as part of their workflow (Source: 2021 Stack Overflow Developer Survey)
• Teams using pull requests find 13% more bugs before deployment (Source: 2019 Forge.io Software Development Trends Survey)
• Projects that use pull requests have a 4.8% lower change failure rate on average (Source: 2021 Accelerate State of DevOps Report)

So, now that we‘ve established why pull requests are so vital, let‘s get into the details of how to use them like a pro!

Anatomy of a Pull Request

Before we dive into creating a pull request, it‘s important to understand the key components that make up a typical pull request in Git:

• Base Branch: This is the branch that you want to merge your changes into, usually the main development branch like master or develop.
• Topic Branch: This is the branch that contains your proposed changes. It‘s sometimes called a feature branch or head branch.
• Commits: A pull request includes all the commits that have been made to the topic branch but are not yet in the base branch.
• Description: This is a markdown-formatted text field where you can describe your changes, provide context, mention related issues, and guide reviewers.
• Reviewers: Most pull request tools allow you to request reviews from specific team members who can then comment on and approve (or reject) your changes.
• Discussions: As reviewers and other team members comment on the pull request, a threaded discussion develops, creating a record of the decision-making process.
• Checks: Many projects integrate automated checks (CI builds, linters, tests, etc.) that run against every pull request and report their status, helping catch issues early.

With these building blocks in mind, let‘s walk through the process of creating a pull request step-by-step.

Creating a Pull Request, Step-by-Step

1. Create a Topic Branch

First things first, before you start making changes, create a new branch specifically for the feature or bugfix you‘re working on. This will isolate your changes and make it easy to manage multiple in-progress pull requests.

To create a new branch and switch to it in one command:

git checkout -b add-new-feature

Give your branch a descriptive name that summarizes the change it introduces. Some teams also like to prefix branch names with the related ticket or issue number for easy cross-referencing, e.g., ABC-123-add-new-feature.

2. Make Your Changes

With your topic branch checked out, you‘re ready to start implementing your changes. Create, edit, and delete files as needed, committing logically related changes together with clear and descriptive commit messages.

Remember, your commit history tells a story about the evolution of your feature or fix, so be intentional about what you include in each commit. A good rule of thumb is that each commit should represent a single logical change and leave the codebase in a working state.

Here are a few sample commits for our add-new-feature branch:

913fc1d Add new feature UI and API endpoints
b9c8a1f Write unit tests for new feature
849d42e Update documentation to cover new feature

3. Push Your Branch

Once you‘re satisfied with your changes and have committed them locally, it‘s time to push your topic branch to the remote repository so that it‘s visible to the rest of the team.

If you‘re working on a fork of the main repository (common in open source workflows), make sure to push your branch to your fork:

git push -u origin add-new-feature

If you‘re working within a single shared repository (typical for internal teams), just push to that repository:

git push -u origin add-new-feature

The -u flag tells Git to set up a tracking relationship between your local and remote branches, so next time you can just use git push without specifying the remote or branch name.

4. Open a Pull Request

Now that your changes are available on the remote repository, you can open a pull request proposing to merge them into the base branch.

On most Git hosting platforms (GitHub, Bitbucket, GitLab, etc.), you can initiate a pull request by visiting the repository web page and clicking the "New Pull Request" or "Create Pull Request" button. If your recently pushed branch is eligible for a pull request, there will often be a handy shortcut button or banner to start one.

When creating your pull request, the key fields to configure are:

• Base Branch: Select the branch you want to merge into (e.g., master)
• Topic Branch: Select the branch containing your changes (e.g., add-new-feature)
• Title: Provide a concise, descriptive title for your pull request
• Description: Write a detailed description of your changes, including context, motivation, design decisions, and anything else that will help your reviewers understand your work

Many teams provide Pull Request Templates that structure and prompt you for key information to include. Using a template helps ensure all pull requests meet a consistent standard of quality and completeness.

Additional options to consider when creating your pull request include:

• Requesting specific reviewers
• Assigning corresponding work items or tickets to track progress
• Linking to related pull requests or issues for more context

Once you‘re happy with your pull request‘s configuration, click "Create Pull Request", and you‘re off to the races!

5. Address Feedback and Update Your Pull Request

After your pull request is opened, your reviewers will be notified and can start examining your changes. They may leave comments either on the pull request overall or on specific lines or sections of code.

Reviewers may also request changes that need to be made before they‘ll approve the pull request and allow it to be merged.

To update your pull request based on feedback:

1. Make the requested changes in your local topic branch
2. Commit the changes and push the new commits to the remote topic branch
3. The pull request will automatically update to reflect your changes
4. Ping your reviewers in a comment to let them know it‘s ready for another look

This iterative review cycle is a core part of what makes pull requests so powerful for collaboration. It allows for asynchronous, in-depth discussion and refinement of code changes before they‘re merged into the main branch.

6. Merge Your Pull Request

Once your pull request has been approved by the necessary reviewers (the exact requirements vary by team and project), it‘s time to merge your changes!

First, double-check that your pull request meets all the merge requirements:

• All required reviews completed and approved
• All automated checks (CI builds, tests, linters, etc.) passing
• No outstanding review comments or change requests
• Topic branch up to date with latest changes in base branch

If everything looks good, it‘s time to merge! Most Git hosting platforms provide a "Merge" button right in the pull request interface. Clicking it will automatically integrate your topic branch changes into the base branch and close the pull request.

Some additional options to consider when merging:

• Merge Strategy: Depending on your Git hosting platform and project configuration, you may be able to choose between a standard merge (creates a new merge commit), a squash merge (condenses all commits into one), or a rebase merge (re-writes commits onto the base branch). Discuss with your team to determine the appropriate strategy for your project.
• Delete Topic Branch: Many teams choose to automatically delete topic branches after merging their associated pull requests to keep the repository clean. Consider enabling this option if available.
• Update Related Work Items: If your pull request completes a task or fixes a bug, make sure to update the status of the corresponding work item or ticket in your project management system.

And with that, your pull request is complete! Congratulations on contributing your changes to the codebase.

Advanced Pull Request Techniques

Now that you‘ve got the basics of pull requests down, let‘s explore a few advanced techniques that can take your pull request game to the next level.

Draft Pull Requests

Sometimes you want to get early feedback on a change or start a discussion before your pull request is fully ready for review. In these cases, you can create a Draft Pull Request.

Draft pull requests cannot be merged until they‘re marked as ready for review, making them a great way to collaborate on changes while they‘re still a work-in-progress.

To create a draft pull request in GitHub, simply choose "Create Draft Pull Request" instead of "Create Pull Request" when opening a new pull request. You can then work on your changes and convert to a regular pull request when you‘re ready for a full review.

Code Owners and Required Reviews

For larger teams and codebases, it‘s often useful to designate specific team members as owners or required reviewers for certain parts of the codebase.

The CODEOWNERS file allows repository maintainers to define which individuals or teams need to review changes to different files or directories. When a pull request modifies code with a designated owner, that owner will automatically be assigned as a reviewer.

Required reviews go a step further and prevent a pull request from being merged until it has been approved by the designated owners. This is a great way to ensure all changes to critical or sensitive parts of the codebase are thoroughly vetted.

To enable code owners and required reviews in GitHub, create a CODEOWNERS file in the root, docs/, or .github/ directory of your repository. Each line in the file specifies a file pattern and one or more owners. For example:

* @global-owner1 @global-owner2
/critical/component/ @critical-team
/sensitive/data/ @data-owner1 @data-owner2

With this CODEOWNERS file in place, pull requests modifying any file in the repository will require approval from both @global-owner1 and @global-owner2, pull requests modifying files in the /critical/component/ directory will additionally require approval from the @critical-team, and so on.

Pull Request Etiquette

Beyond the technical aspects of creating and managing pull requests, there‘s also an important social component to collaborative development. By following pull request etiquette and being a good citizen of your team‘s development culture, you can make the review process smoother and more effective for everyone.

Here are a few key principles of pull request etiquette:

• Be Respectful: Remember that every comment in a pull request is directed at a person, not just code. Phrase feedback constructively and avoid personal attacks or dismissive language. Assume positive intent from your fellow developers.
• Be Responsive: When you open a pull request, be prepared to engage in discussion and address feedback in a timely manner. Don‘t leave your reviewers hanging or your pull request stagnant for long periods.
• Be Humble: Approach the review process with a growth mindset. Be open to constructive criticism and willing to learn from your teammates. Remember that everyone is working towards the same goal of improving the codebase.
• Be Proactive: Don‘t wait for your reviewers to catch every issue. Before opening a pull request, self-review your changes and try to anticipate questions or feedback. Include comments or documentation to provide context and rationalization for your approach.

By following these principles and setting a positive example, you can help foster a collaborative and effective pull request culture on your team.

Conclusion

And there you have it! A comprehensive guide to mastering the art of pull requests.

We‘ve covered a lot of ground, from the basic workflow of creating and merging pull requests, to advanced techniques like draft pull requests and code owners, to the softer skills of pull request etiquette and collaboration.

As you can see, pull requests are an incredibly powerful tool for facilitating code review, knowledge sharing, and asynchronous collaboration on development teams of all sizes. By following the best practices and techniques outlined in this guide, you‘ll be well on your way to pull request mastery.

But don‘t just take my word for it! The real learning comes from putting these concepts into practice in your own projects and teams. So get out there and start opening, reviewing, and merging pull requests like a pro.

Happy collaborating!