GraphQL Mutation exceptions when no setters are present.

[zbhavyai]

Hello,

With Quarkus GraphQL, I am facing couple of exceptions with mutations when setters are not present in the model class. I made a small reproducer for this, which is available at https://github.com/zbhavyai/quarkus-graphql-nosetters-reproducer.

To explain, the Film class has no setters. The REST endpoints to add a Film works fine. The GraphQL mutations however throw exception - Cannot create instance of a class. No default constructor found. When I add a default constructor, InvalidSchemaException is thrown at build time.

The exceptions faced might be somewhat related to https://github.com/smallrye/smallrye-graphql/issues/1342, but I am not sure if the actual issue is related at all.

So, my question is - why exactly are setters required? If REST works fine without them, shouldn't GraphQL too? Is it bug or GraphQL limitation?

Thanks in advance.

[phillip-kruger]

To be able to do a mutation you are going to need setters. Why do you not have setters ?

[zbhavyai]

Because, I am building a GraphQL wrapper on an existing service that doesn't have setters. The REST wrapper on that works without any issues, so I wondered why GraphQL doesn't work.

[zbhavyai]

Is there any particular reason why GraphQL mutation need setters? IMHO the parameterized constructors should be enough to create the object using the Jackson deserialization.

Thanks.

[robp94]

If I remember correctly, the quarkus version still uses jsonb. If you don't have setters, you need to do something like this for the server input objects https://github.com/smallrye/smallrye-graphql/blob/3f7a7ab79ade1b049a73ff4a0e66128d171ee7d3/server/integration-tests-jdk16/src/test/java/io/smallrye/graphql/tests/records/RecordTest.java#L103

[zbhavyai]

@robp94 Yeah this one works after I update my constructor with @JsonbCreator. Thanks for letting this know!

[zbhavyai]

Want to check, can we have Jackson support for Quarkus GraphQL?

[phillip-kruger]

What do you mean by Jackson support?

[zbhavyai]

To put it simply, expecting GraphQL mutations to work with @JsonCreater annotated constructor rather than to rely on @JsonbCreator as robp94 suggested.

[phillip-kruger]

Should be possible. Let's leave this open and we can look at it at some point. Or you can do a PR if you are keen.

[phillip-kruger]

I think this should work with com.fasterxml.jackson.annotation.JsonCreator ( at least I see the code for it: https://github.com/smallrye/smallrye-graphql/blob/a7216b53ea69dda57fcc2d33766b6caf9b44b615/common/schema-builder/src/main/java/io/smallrye/graphql/schema/Annotations.java#L615)

[zbhavyai]

Not sure if you meant to do it differently (posted reproducer does uses @JsonCreator), but I see the exact same error. Tried with quarkus version 2.11.1.Final. Again, @JsonbCreator works but not @JsonCreator.

[phillip-kruger]

Yes initially I thought we don't support it, but we do, as the annotations are there, so this is a bug