A GitHub workflow to check the compatibility of your PHP package with a range of dependency versions

A common aspect of a PHP developer's job is to deal with Composer dependencies. We don't usually need to think about supporting various versions of these dependencies, just as we don't need to think about accommodating a range of PHP versions. Things are different for open-source software maintainers – they need to ensure their libraries will work with as many environments as possible. This post explores one way of automating compatibility testing, using a combination of test coverage and a GitHub workflow.