Use type declarations, and strict_types mode

[mallorydxw]

• Use type declarations for arguments and return values
• declare(strict_types=1);

[patdel0]

To enforce the use of strict_types=1 in future files, we could add the following code to our php-cs-fixer.php file.

return \Dxw\PhpCsFixerConfig\Config::create()
->setRiskyAllowed(true)
->setRules(['declare_strict_types'=> true])
->setFinder($finder);

I'm not sure what the effects of setRiskyAllowed(true) will be. As I understand it, 'risky' means that existing code may not work due to the PHP engine enforcing strict type checking, which is what we want.

There isn't much documentation on the behaviour of this setting. However, I came across a discussion about it by one of the contributors on this page: PHP-CS-Fixer/PHP-CS-Fixer#4653.

What are our thoughts on adding this to our project?