Testing PHP Applications Across Multiple Supported PHP Versions

A test matrix runs the same suite on each supported PHP version to expose language and extension compatibility regressions.

What It Does

CI matrices catch compatibility problems across supported PHP versions. Install reproducibly before executing the test suite.

Requirements and Compatibility

Use a supported PHP runtime and install any third-party tool or extension explicitly shown in the examples. Commands should be run from the project root unless stated otherwise.

Syntax, Inputs and Results

The examples separate configuration, the smallest working operation and a realistic follow-up task. Adapt file paths and dependency versions to your own project.

Example 1: Basic Use

CI matrices catch compatibility problems across supported PHP versions.

name: PHP Tests
on: [push, pull_request]
jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        php: ['8.3', '8.4']
    steps:
      - uses: actions/checkout@v4
      - uses: shivammathur/setup-php@v2
        with: {php-version: '${{ matrix.php }}'}
      - run: composer install --no-interaction --prefer-dist
      - run: vendor/bin/phpunit

Example 2: Another Case

Install reproducibly before executing the test suite.

composer validate --strict
composer install --no-interaction --prefer-dist
vendor/bin/phpunit --colors=never

Practical Example

A minimal GitLab job can begin with syntax checking and add Composer/tests later.

stages: [test]
php_tests:
  image: php:8.4-cli
  stage: test
  script:
    - php -v
    - php -l src/bootstrap.php

For production, apply the compatibility and edge-case limits described below.

Important Behavior and Edge Cases

Mocking every collaborator can hide real integration failures.

Comparison with Related Functions and Tools

Subject	Key difference
Local test run vs CI pipeline	CI reproduces a declared PHP environment and runs checks on each change.

Common Beginner Mistakes

Mistake	Correct approach
Installing dependencies without a lockfile	Use committed dependency versions and a declared PHP runtime in CI.
Skipping the prerequisite of this specific workflow	Install or configure the named tool and confirm the example can actually run.
Ignoring edge conditions	Mocking every collaborator can hide real integration failures.

Key Takeaways

A test matrix runs the same suite on each supported PHP version to expose language and extension compatibility regressions.
Mocking every collaborator can hide real integration failures.
Keep application configuration, source code and validation tests under version control.

Use these examples as a starting point, then validate the result with the actual PHP build, dependencies and inputs used by your application.