Delta Action

A GitHub Action for reporting benchmark data and comparing it against a baseline.

The basics

This action reads benchmark metrics on GitHub pull requests and commits, and reports them by adding a comment with any metrics found. It also compares then against the latest commit on the main branch, treating it as the baseline.

The action looks for benchmark data in files on the repository root. These should be named in the format .delta.<metric name> — e.g. .delta.install_time will create a metric called install_time.

These files should contain:

• A number representing the value of the metric
• The units of the metric (optional)
• A human-friendly name of the metric (optional)

Example: .delta.install_time

350ms (Installation time)

The units will determine how the values will be formatted in the benchmark reports. Supported units are:

• Time (formatted with pretty-ms)
  • ms / milliseconds
  • s / seconds
• Storage (formatted with pretty-bytes)
  • b / bytes
  • kb / kilobytes
• Unitless (formatted with Number.prototype.toLocaleString)

Configuration

The action supports the following optional inputs:

Name	Description	Default
base_branch	Name of the base branch, if not auto detected	autodetect
title	Title/heading to include in the comments	Delta results
token	GitHub access token	GITHUB_TOKEN
pr_number	The PR this run is associated with (for workflow_run)	autodetect
style	The rendering style to use when commenting on PRs (options: text, graph)	graph

Usage

1. Add a benchmark step to your workflow that creates a .delta.<metric> file with the format described above

- name: Run benchmark
  run: echo 123ms > .delta.install_time

2. Add the action to the workflow

   - name: Delta
     uses: netlify/delta-action@v3
     with:
       token: ${{ secrets.GITHUB_TOKEN }}

Contributors

Please see CONTRIBUTING.md for instructions on how to set up and work on this repository. Thanks for contributing!