[Experiment][TypeDeclaration] Allow change abstract class methods with body on ReturnType*Rector

[samsonasik]

@TomasVotruba @staabm based on child return type sub type verification on previous PR:

• [TypeDeclaration] Skip has child return different type on ReturnNeverTypeRector #5343

This is experiment to allow abstract class methods with body to make return type as well on ClassMethodReturnTypeOverrideGuard service.

[samsonasik]

For change in vendor + non-vendor location, it already verified on isReturnTypeChangeAllowed() method 👍

[samsonasik]

All checks have passed 🎉 @TomasVotruba @staabm it is ready for review.

[samsonasik]

Ok, It seems it will cause a bug on union:

abstract class SomeAbstractWithUnion
{
    public function run()
    {
        if (rand(0, 1)) {
            return null;
        }

        return new \DateTime;
    }
}

final class NullableUnion extends SomeAbstractWithUnion
{
    public function run()
    {
        if (rand(0, 1)) {
            return null;
        }

        return new stdClass;
    }
}

it got:

 abstract class SomeAbstractWithUnion
 {
-    public function run()
+    public function run(): ?\DateTime
     {
         if (rand(0, 1)) {
             return null;
@@ @@
 
 final class NullableUnion extends SomeAbstractWithUnion
 {
-    public function run()
+    public function run(): ?\stdClass
     {
         if (rand(0, 1)) {
             return null;

on union type, it specifically on child verification tho, nothing todo with abstract, I will check in separate PR.

[samsonasik]

Oh, it seems fine, it because I wrongly copy paste class name, I will add the fixture

[samsonasik]

Added more fixtures :), Ready to review 👍

[samsonasik]

Ok, interface never have method with body, so I guess it can be rolled back for performance reason to skip it.

[samsonasik]

this is skip only on abstract method only, not abstract class 👍

[TomasVotruba]

@samsonasik Feel free to go for merge, let's try this in real world 😉

[samsonasik]

Ok, let's merge it ;)