GraphQlTester: Type inference issues with Kotlin

[koenpunt]

Similar to the type inference issues that were present with the WebTestClient.BodySpec, there are now also issues here with the GraphQlTester.EntitySpec.

So for example, the following code will not compile;

graphQlTester
  .query(query)
  .execute()
  .path("merchants.edges[0].node.id")
  .entity(String::class.java)
  .isEqualTo<String>(id)

It will instead result it the following error:

Type argument is not within its bounds.
Expected: Nothing!
Found: String!

Changing String to Nothing satisfies the compiler, but errors out at runtime with a KotlinNothingValueException.

graphQlTester
  .query(query)
  .execute()
  .path("merchants.edges[0].node.id")
  .entity(String::class.java)
  .isEqualTo<Nothing>(id)

The expected/preferred kotlin api would be something like:

graphQlTester
  .query(query)
  .execute()
  .path("merchants.edges[0].node.id")
  .entity<String>()
  .isEqualTo(id)

[jisensee]

Running into the same issue, didn't find a way to make this work either.
FWIW, one can use the get method on the EntitySpec to obtain the result and do manual assertions as a workaround.

[sdeleuze]

Fixed on Kotlin side, see this blog post for more details. This is available via a flag in Kotlin 1.5.30 and by default in the upcoming Kotlin 1.6 release.

[rstoyanchev]

Closing this in light of that. Thanks @sdeleuze for the update.