fix bug in isSubtypeOf (broken contract X.isSubtypeOf(X)==true)

[pvojtechovsky]

There are two implementations of CtTypeInformation#isSubtypeOf(CtTypeReference), which has following comment:

Returns true if the referenced type is a sub-type of the given type.

and two implementations:

1. CtTypeReferenceImpl#isSubtypeOf
2. CtTypeImpl#isSubtypeOf

There is bug that each implementation behaves different. See the failing test of this PR.

//contract: x.isSubtypeOf(x)==true
//using CtTypeReference implementation - test pass
assertTrue(xCtType.getReference().isSubtypeOf(xCtType.getReference()));
//using CtType implementation - test fails
assertTrue(xCtType.isSubtypeOf(xCtType.getReference()));

Which behavior is correct? I personally thought that x.isSubtypeOf(x)==true is correct. But I have seen code which expected opposite...

Should we fix it? How?

[monperrus]

Thanks for the report. They should have the same behavior and x.isSubtypeOf(x)==true is correct. Do you fix it?

[pvojtechovsky]

May be I can fix it this evening. We will see if I will have time.
But if you have time for that, then I can do something else :-)

[pvojtechovsky]

@surli wrote: However we should discuss the implementation of isSubTypeOf for TypeParameters: it wasn't supported until now.

I personally have nothing for this topic. I have not touched that problem/code/need yet. I suggest to discuss it in different PR/Issue, so this PR can be finished fast and I can fix other related problems in FieldReferenceFunction, which is actually broken... I will provide better tests and fixes for FieldReferenceFunction soon.

I commented the test for isSubTypeOf for TypeParameters, so this PR pass all other tests well and can be merged.

[spoon-bot]

Revapi Analysis results

Old API: fr.inria.gforge.spoon:spoon-core:jar:5.6.0-20170131.234706-21

New API: fr.inria.gforge.spoon:spoon-core:jar:5.6.0-SNAPSHOT

Detected changes: 0.

[spoon-bot]

Revapi Analysis results

Old API: fr.inria.gforge.spoon:spoon-core:jar:5.6.0-20170131.234706-21

New API: fr.inria.gforge.spoon:spoon-core:jar:5.6.0-SNAPSHOT

Detected changes: 0.

[surli]

I suggest to discuss it in different PR/Issue, so this PR can be finished fast and I can fix other related problems in FieldReferenceFunction, which is actually broken... I will provide better tests and fixes for FieldReferenceFunction soon.
I commented the test for isSubTypeOf for TypeParameters, so this PR pass all other tests well and can be merged.

Great, indeed it should be done in another PR. I open an issue.

[spoon-bot]

Revapi Analysis results

Old API: fr.inria.gforge.spoon:spoon-core:jar:5.6.0-20170201.234549-22

New API: fr.inria.gforge.spoon:spoon-core:jar:5.6.0-SNAPSHOT

Detected changes: 0.