How to Collate Code Coverage from Multiple Jobs in Azure Pipeline?

Are you tired of manually aggregating code coverage reports from multiple jobs in Azure Pipeline? Do you want to know the secret to effortlessly combining code coverage results from diverse jobs and getting a comprehensive view of your code’s health? Well, buckle up, friend, because we’re about to embark on a thrilling adventure to conquer the realm of code coverage collation in Azure Pipeline!

Why Collate Code Coverage from Multiple Jobs?

Before we dive into the how-to, let’s take a step back and understand the importance of collating code coverage from multiple jobs. In a CI/CD pipeline, multiple jobs are often executed in parallel to speed up the build and testing process. Each job may execute different tests, targeting distinct areas of your codebase. If you don’t collate the code coverage results from these jobs, you’ll miss out on the bigger picture of your code’s coverage.

By collating code coverage, you can:

• Get a unified view of your code’s coverage across multiple jobs
• Identify areas with low coverage and prioritize testing efforts
• Improve the overall quality and reliability of your codebase

The Challenges of Collating Code Coverage

So, why is collating code coverage from multiple jobs such a daunting task? Here are some common challenges you might face:

• Different test frameworks and tools generate varying formats of code coverage reports
• Jobs may run on different agents, making it difficult to collect and merge coverage data
• Merging coverage reports from multiple jobs requires careful attention to detail and formatting

The Solution: Using Azure Pipeline and the Cobertura Plugin

Fear not, dear developer! Azure Pipeline, in conjunction with the Cobertura plugin, provides an elegant solution to collate code coverage from multiple jobs. Cobertura is a popular code coverage tool that can merge coverage reports from various sources.

Here’s an overview of the process:

1. Configure each job in Azure Pipeline to generate code coverage reports in Cobertura format
2. Use the Cobertura plugin to merge the coverage reports from multiple jobs
3. Publish the merged coverage report as an Azure Pipeline artifact

Step-by-Step Guide to Collating Code Coverage

Now that we’ve set the stage, let’s dive into the step-by-step instructions to collate code coverage from multiple jobs in Azure Pipeline:

Step 1: Configure Code Coverage in Each Job

In each job, you need to configure the code coverage tool to generate reports in Cobertura format. For example, if you’re using .NET Core and the dotnet CLI, you can use the following command:

dotnet test /p:CollectCoverage=true /p:CoverletOutputFormat=cobertura

This will generate a Cobertura coverage report for each job.

Step 2: Create a New Azure Pipeline Job to Merge Coverage Reports

Create a new Azure Pipeline job, which we’ll call the “merge job.” This job will be responsible for merging the coverage reports from the individual jobs.

In the merge job, add a new task to install the Cobertura plugin:

pipeline {
  tasks: {
    CoberturaInstall@1: {
      displayName: 'Install Cobertura'
    }
  }
}

Step 3: Download and Merge Coverage Reports

Add a new task to download the coverage reports from each individual job and merge them using the Cobertura plugin:

tasks: {
  DownloadPipelineArtifact@1: {
    displayName: 'Download Coverage Reports',
    artifactName: 'coverage-report'
  },
  CoberturaMerge@1: {
    displayName: 'Merge Coverage Reports',
    reports: '**/*.cobertura.xml',
    output: 'merged-coverage-report.cobertura.xml'
  }
}

This task will download the coverage reports from each individual job and merge them into a single report.

Step 4: Publish the Merged Coverage Report

Finally, publish the merged coverage report as an Azure Pipeline artifact:

tasks: {
  PublishPipelineArtifact@1: {
    displayName: 'Publish Merged Coverage Report',
    targetPath: 'merged-coverage-report.cobertura.xml',
    artifactName: 'merged-coverage-report'
  }
}

Visualizing the Merged Coverage Report

Now that you’ve merged the coverage reports, you’ll want to visualize the results. You can use a tool like Azure DevOps’ built-in code coverage report feature or a third-party extension like Code Coverage Explorer.

Here’s an example of how you can configure the code coverage report feature in Azure DevOps:

tasks: {
  PublishCodeCoverageInfo@1: {
    displayName: 'Publish Code Coverage Info',
    codeCoverageTool: 'Cobertura',
    summaryFile: 'merged-coverage-report.cobertura.xml'
  }
}

This will publish the merged coverage report, and you can view the results in the Azure DevOps pipeline summary:

Metric	Value
Line Coverage	85%
Branch Coverage	75%
Method Coverage	90%

Conclusion

Voilà! You’ve successfully collated code coverage from multiple jobs in Azure Pipeline using the Cobertura plugin. By following these steps, you’ll get a unified view of your code’s coverage, identify areas for improvement, and ensure the overall quality of your codebase.

Remember, code coverage is just one aspect of ensuring code quality. By combining code coverage with other metrics, such as code health and testing quality, you’ll get a comprehensive view of your code’s overall health.

Happy coding, and may the code coverage be with you!

Frequently Asked Question

Are you struggling to collate code coverage from multiple jobs in Azure Pipeline? Don’t worry, we’ve got you covered! Here are the answers to the most frequently asked questions about code coverage collation in Azure Pipeline.