Explicitly mark nullable parameter

[cedric-anne]

Some occurences were missed.

I did not pushed the fixes yet, I want to first check if the updated PHPStan configuration will help to detect them. I do not know how to detect them in the CI.

[cedric-anne]

@staabm @phil-davis

This PR is ready to be reviewed.

[phil-davis]

I do not know how to detect them in the CI.

I have been playing around to try and work out how to make phpstan find all the problems - I haven't succeeded yet.

It doesn't seem to find examples that are not in a class.

[cedric-anne]

I do not know how to detect them in the CI.

I have been playing around to try and work out how to make phpstan find all the problems - I haven't succeeded yet.

It doesn't seem to find examples that are not in a class.

As far as I remember, in our project, we force the PHP version required in the composer.json file in our CI, to be sure that PHPStan executes its check accordingly to the PHP version defined in the matrix.

Something like composer require "php:>=${{ matrix.php-version }}" --ignore-platform-req=php+ --no-install --no-scripts. The + suffix on php+ indicates to ignore the upper bound of the dependencies, see https://getcomposer.org/doc/03-cli.md#install-i