ResolvableType for a raw type is not assignable to generic types of the same class [SPR-14648]

[spring-projects-issues]

Oliver Drotbohm opened SPR-14648 and commented

This test case fails for me and I think it shouldn't as a concrete generic type should always be assignable to a raw variant of it:

public class RawTypeAssignmentTests {

	@Test
	public void rawTypeShouldBeassignable() throws Exception {

		// That works.
		Collection value = someMethod();
		
		// So that should, too.
		ResolvableType fromClass = ResolvableType.forClass(Collection.class);
		ResolvableType fromReturnType = ResolvableType.forMethodReturnType(RawTypeAssignmentTests.class.getMethod("someMethod"));

		assertThat(fromClass.isAssignableFrom(fromReturnType), is(true));
	}

	public Collection<?> someMethod() {
		return Collections.emptyList();
	}
}

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Affects: 4.2.7, 4.3.2, 5.0 M1

Issue Links:

• DATAREST-881 ResourceProcessor is not invoked if RepositoryEntityController does not return a subtype of Resources ("is depended on by")

Backported to: 4.2.8

[spring-projects-issues]

Juergen Hoeller commented

The snippet above should be using ResolvableType.forRawClass(Class), then it should indeed be working. However, it is only actually working with ResolvableType.isAssignableFrom(Class) then, not with ResolvableType.isAssignableFrom(ResolvableType). I've fixed that gap for 4.3.3 / 4.2.8.