Making PHPStan stricter

Continuing yesterday's thought on strictness in PHP, today I want to talk about adding more strictness to PHPStan.

Adding the PHPStan Strict Rules extension makes PHPStan stricter by adding new, more opinionated rules.

For example:

  • Require booleans in if, elseif, ternary operator, after !, and on both sides of && and ||.
  • Use the $strict parameter with in_array, array_search, array_keys and base64_decode.
  • Disallow empty().
  • Require calling parent constructor.

You can enable and disable rules as needed but, like setting the PHPStan level, ideally I like to enable them all by default and see how strict I go.

It depends on the code being tested and the preference of the team, though I find the stricter the rules, the less bugs there are.