Enforce parameter and return value types in the codebase

[morozov]

Q	A
Type	improvement
BC Break	yes
Fixed issues	none

Enabled SlevomatCodingStandard.TypeHints.TypeHintDeclaration.Missing{Parameter,Return}TypeHint sniffs across the codebase.

[Majkl578]

This looks impossible to review and properly document. Who don't we do it in smaller parts?

Also eliminating type casts/checks is probably task for separate PR (PHPStan should catch them).

[morozov]

Clean up type casting and checks like (bool) $flag or is_string($string) which are no longer needed.

Also eliminating type casts/checks is probably task for separate PR (PHPStan should catch them).

I just though about the same. Will double check if PHPStan can do that and will file a ticket otherwilse and attach it here.

[Majkl578]

It definitely does, but probably on higher level than we have.
IMO we should've first worked on level 7 and then on enabling scalar types, this way we may end up with fatal errors in uncovered code (100% coverage is a dream).

[morozov]

This looks impossible to review and properly document. Why don't we do it in smaller parts?

I'd better try to come up with a systems approach of reviewing what's already done then splitting it apart and then putting back together. It took me a week to make this change including almost one day full time, and I may not have that much time for additional coding.

[morozov]

IMO we should've first worked on level 7 and then on enabling scalar types, this way we may end up with fatal errors in uncovered code (100% coverage is a dream).

I'd better have the branch destabilized but with all the code changes in place instead of not doing anything. AFAIK, the work on a higher PHPStan level and enabling strict types was started long ago but wasn't finished.

With this approach, we can have more non-covered breakages reported by users of develop and add more test coverage based on that.

[Majkl578]

PHPStan level and enabling strict types was started long ago but wasn't finished.

Hmm, where? Maybe I just forgot.
Enabling strict types is separate task, not blocking scalar types or PHPStan level upgrade.

[morozov]

Hmm, where? Maybe I just forgot.

I meant #3260 and #2854.

Enabling strict types is separate task, not blocking scalar types

I see. I misread this:

IMO we should've first worked on level 7 and then on enabling scalar types

[Ocramius]

Possibly a good idea to have #2854 in first - would catch a lot of runtime errors due to type mismatch, if there are any left

[morozov]

Yea, we discussed that internally.