[Amoifr]

Closes #445

The stub only declared create() and createNamed(), so the builder methods fell back to Symfony's own signature and returned a plain FormBuilderInterface, with mixed data. They now carry the same templates as their create*() counterparts and return FormBuilderInterface<TData> (or <null|TData> without data), so $builder->getData() and $builder->getForm() keep the data type of the form type.

One limit worth knowing: like create(), this only helps with a generic form type (AbstractType<Foo>). With the core FormType::class from the issue, TData stays mixed, exactly as create(FormType::class, new Foo()) does today.

createForProperty() and createBuilderForProperty() are left alone, since there is no form type to take the data type from.

[staabm]

I am not a symfony expert. do these newly added method types hold across all supported symfony versions of phpstan-symfony?

//cc @SanderMuller

[SanderMuller]

Yes. I checked FormFactoryInterface in Symfony 3.4, 4.4, 5.4, 6.4, 7.3 and 8.0. createBuilder() and createNamedBuilder() exist in all of them with the same parameter names and a FormBuilderInterface return. Only the native types differ, which matches how the existing create() and createNamed() entries in this stub are written.

The new tests pass with lowest (symfony/form 5.4.0) and highest (6.4.48) dependencies, and fail without the stub change. I also checked the default FormType, a non-generic type and TextType: the data stays mixed, the same as create() today.

[staabm]

Thank you!