How to track code review metrics in GitHub

Tracking code review metrics in GitHub is important for understanding the effectiveness of your code review process and enhancing overall code quality. Metrics provide insights into various aspects of code reviews, including speed, quality, and team performance. In this guide, we will explore how to measure these metrics, the tools available in GitHub, and how to leverage Graphite Insights to optimize your code review process.

Understanding GitHub code review metrics

GitHub code review metrics encompass various data points that help teams assess their code review process. These metrics can be broadly categorized into:

• Performance metrics: Measure the speed and efficiency of the code review process.
• Quality metrics: Evaluate the impact of code reviews on code quality.
• Participation metrics: Track team engagement and collaboration during the review process.

Key code review metrics to track

1. Review time: The total time taken for a pull request (PR) to be reviewed. This metric helps assess the responsiveness of the team.
2. Time to merge: The time from when a PR is created to when it is merged. This metric indicates the efficiency of the code review process.
3. Review feedback: The number and type of comments made during reviews. This metric helps evaluate the thoroughness of the review process.
4. Approval rate: The percentage of PRs that get approved without requiring changes. This metric indicates the quality of the code being submitted.
5. Post-merge bugs: The number of bugs or issues reported after merging code, which reflects the effectiveness of the review process.

Setting up tracking for GitHub code review metrics

To effectively track code review metrics in GitHub, you can use the built-in features of GitHub along with additional tools. Here’s how to get started:

1. Using GitHub’s insights

GitHub offers some basic insights into repository activity, which can help you monitor code review processes:

• Navigate to your repository: Go to your repository on GitHub.
• Access the insights tab: Click on the Insights tab at the top of the page.
• Explore activity metrics:
  • Pulse: Under Insights, select Pulse to view recent activity, including pull requests opened, closed, and merged.
  • Contributors: View contributions from team members, such as commits and code changes.
  • Commits and code frequency: Analyze commit history and code additions or deletions over time.

2. Leveraging third-party tools

While GitHub’s built-in features provide some insights, third-party tools can offer more comprehensive tracking of code review metrics. One such tool is Graphite Insights, which provides detailed analytics for pull request performance and team collaboration.

Setting up Graphite Insights

To set up Graphite Insights for tracking code review metrics:

• Authorize Graphite: Follow the instructions in the Graphite documentation to authorize Graphite in your repository.

• Connect your GitHub repository: Link your GitHub account and select the repository you want to track.

• Configure metrics tracking: Define the specific metrics you want to monitor. Graphite Insights will allow you to track stats like:

  • Median publish to merge time
  • Median wait time to first review
  • Average number of review cycles until merge

• Review your dashboard: Once set up, you can view a dashboard that displays various metrics, allowing for easy monitoring and analysis.

Example: Measuring code review performance

Let’s say your team has been experiencing delays in merging pull requests. By using Graphite Insights, you can track the following metrics over a defined period:

• Average review time: Identify the average time taken for reviews.
• Time to merge: Analyze how long it takes from PR creation to merging.

This data will help you pinpoint bottlenecks in the process. For instance, if the average review time is significantly high, it may indicate that the team needs more reviewers or that the review process needs to be streamlined.

Tracking code review metrics using GitHub API

For advanced users, you can also utilize the GitHub API to extract code review metrics programmatically. This allows for custom reporting and further analysis. Here’s a brief overview of how to use the GitHub API for tracking:

1. Authenticate: Use your GitHub token to authenticate with the API.

2. Fetch pull requests: Use the following endpoint to fetch pull requests for your repository:

   Terminal

   GET /repos/{owner}/{repo}/pulls
   
   

   This will return a list of pull requests, including their state (open, closed, merged), review comments, and timestamps.

3. Analyze the data: From the response, you can calculate metrics like review time and approval rates. For example:

   Terminal

   import requests
   
   repo = 'your-repo-name'
   owner = 'your-github-username'
   token = 'your-github-token'
   url = f'https://api.github.com/repos/{owner}/{repo}/pulls'
   
   response = requests.get(url, auth=(owner, token))
   pulls = response.json()
   
   for pull in pulls:
       print(f"PR #{pull['number']}: created at {pull['created_at']}, merged at {pull['merged_at']}")
   
   

Takeaways

Tracking code review metrics in GitHub is an important step in elevating your development process. By harnessing GitHub's built-in insights, integrating tools like Graphite Insights, and utilizing the GitHub API for tailored reporting, you unlock a wealth of information about your code review performance. Regularly analyzing these metrics can drastically improve your software development workflow, leading to enhanced efficiency, superior code quality, and a more motivated and engaged development team.