[TomasVotruba]

Why

Following rectorphp/rector-src#8791, the engine skips the format-preserving print when a pass records no change (refactor() returns null). Rules that mutate the AST in place but then return null on some branch now have their change silently dropped.

FormTypeInstanceToClassConstRector hit this: for the collection case ($formBuilder->add('tags', 'collection', ['entry_type' => new TagType()])), refactorCollectionOptions() rewrites $arrayItem->value (new TagType() -> TagType::class) in place, but the method then returns via processNewInstance($node, 1, 2), which returns null because position 1 is the string 'collection', not a new. The whole refactor() returned null and the applied mutation was dropped.

Fix

refactorCollectionOptions() now returns whether it changed anything. When processNewInstance() yields no new call but the collection options were mutated, refactor() returns the already-mutated $node so the change is reported through the return value per the refactor() contract. Output is unchanged - only the return value differs.

Tested

• phpunit green against rector-src main (543 tests, 732 assertions)
• phpunit green against the [perf] Skip format-preserving print for unchanged files rector-src#8791 branch (543 tests, 732 assertions)
• ECS clean on the changed file