Incorrect arguments to Assert.isInstanceOf in AnnotatedControllerConfigurer

[voydz]

Hi there,

first of all thank you for your awesome work. I noticed a potential bug on the M5 release of spring-boot-graphql. Upon launching my application the exception "Object of class [java.lang.String] must be an instance of class org.springframework.format.support.FormattingConversionService" occurs.

After a bit of digging in the code I noticed a potential bug in the following line:

spring-graphql/spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerConfigurer.java

Line 135 in 0b449d8

Assert.isInstanceOf(FormattingConversionService.class, "FormattingConversionService is required");

I am no expert in this by all means, but isn't the second argument of the assert the actual object to check? Thus passing the message as the second argument would raise the exception shown above.

It was introduced with 0b449d8 to fix #271.

[voydz]

For reference:

As a workaround I am defining the annotatedControllerConfigurer bean myself without calling the faulty setConversionService. This works because the AnnotatedControllerConfigurer is already initialized with the DefaultFormattingConversionService.

@Bean
fun annotatedControllerConfigurer(): AnnotatedControllerConfigurer? {
    return AnnotatedControllerConfigurer()
}

[bclozel]

Could you tell us which Spring for GraphQL and Spring Boot versions are you using to reproduce that?

[voydz]

I am using Spring Boot 2.6.3 and Spring for GraphQL 1.0.0-M5

[bclozel]

I see - those are incompatible versions.
As of Spring for GraphQL 1.0.0-M5, we've moved the auto-configuration to Spring Boot proper.

You can get a default setup with start.spring.io (by selecting the latest 2.7.x milestone or snapshot).
Thanks for this report!

[voydz]

Thats fine. I take that note. But did you actually look at the linked line in the code? I am quite convinced, that there is an issue anyway. This issue is not raised from version incompatibility.

Here is another use of Assert.isInstanceOf() in the codebase

spring-graphql/spring-graphql/src/main/java/org/springframework/graphql/data/query/AutoRegistrationRuntimeWiringConfigurer.java

Line 115 in 5ff3f8b

Assert.isInstanceOf(GraphQLNamedOutputType.class, type);

and the signature differs from the one I mentioned above.

In other words: This issue will persist in Spring Boot 2.7.0-M1 and 3.0.0-SNAPSHOT

[rstoyanchev]

This appears to be an issue with the Assert arguments indeed.

[voydz]

@rstoyanchev @bclozel Thank you very much for looking into this.

best regards