Roave Backward Compatibility Check

A tool that can be used to verify BC breaks between two versions of a PHP library.

[!TIP] Enjoy checking your API compatibility :) if you need help with this tool, auditing your code, or support on your legacy applications, feel free to get in touch.

- The Roave Team

Pre-requisites/assumptions

• Your project uses git
• Your project uses composer.json to define its dependencies
• All source paths are covered by an "autoload" section in composer.json
• Changes need to be committed to git to be covered. You can implement your own logic to extract sources and dependencies from a project though.

Installation

composer require --dev roave/backward-compatibility-check

Install with Docker

You can also use Docker to run roave-backward-compatibility-check:

docker run --rm -v `pwd`:/app nyholm/roave-bc-check

Usage

Adding to a continuous integration pipeline

The typical intended usage is to just add roave-backward-compatibility-check to your CI build:

vendor/bin/roave-backward-compatibility-check

This will automatically detect the last minor version tagged, and compare the API against the current HEAD. If any BC breaks are found, the tool returns a non-zero status, which on most CI systems will cause the build to fail.

NOTE: detecting the base version only works if you have git tags in the SemVer-compliant x.y.z format, such as 1.2.3.

NOTE: since this tool relies on tags, you need to make sure tags are fetched as part of your CI pipeline. For example in a GitHub action, note the use of fetch-depth: 0:

jobs:
  roave-backwards-compatibility-check:
    name: Roave Backwards Compatibility Check
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0
      - name: "Install PHP"
        uses: shivammathur/setup-php@v2
        with:
          php-version: "8.0"
      - name: "Install dependencies"
        run: "composer install"
      - name: "Check for BC breaks"
        run: "vendor/bin/roave-backward-compatibility-check"

Nyholm Github Action

Tobias Nyholm also offers a simple GitHub action that you can use in your Github pipeline. We recommend this for most cases as it is simple to set up:

.github/workflows/main.yml:

on: [push]
name: Test
jobs:
  roave-backwards-compatibility-check:
    name: Roave Backwards Compatibility Check
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
        with:
          fetch-depth: 0
      - name: "Check for BC breaks"
        uses: docker://nyholm/roave-bc-check-ga

Running manually

To generate additional documentation for changelogs:

vendor/bin/roave-backward-compatibility-check --format=markdown > results.md

GitHub Actions

When running in GitHub Actions, it is endorsed to use the --format=github-actions output format:

vendor/bin/roave-backward-compatibility-check --format=github-actions

Documentation

If you need further guidance:

vendor/bin/roave-backward-compatibility-check --help

Configuration

The file .roave-backward-compatibility-check.xml is read from the current working directory (when it exists) and sets configuration for the command.

It's expected to be an XML file that follows our schema:

Example:

<?xml version="1.0" encoding="UTF-8" ?>
<roave-bc-check
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:noNamespaceSchemaLocation="vendor/roave/backward-compatibility-check/Resources/schema.xsd">
    <baseline>
        <ignored-regex>#\[BC\] CHANGED: The parameter \$a of TestArtifact\\TheClass\#method\(\)#</ignored-regex>
        <ignored-regex>#\[BC\] CHANGED: The parameter \$b of TestArtifact\\TheClass\#method2\(\)#</ignored-regex>
    </baseline>
</roave-bc-check>