Build example for schema: error with SpringWolf 1.4.0, but working fine with 1.2.0

[pdalfarr]

Describe the bug
Schema generation was working fine with SpringWolf 1.2.0.
I changed version from 1.2.0 to 1.4.0: as a result, my Spring app is working fine, but Springwolf does not work.
See log message and stack trace below.

Dependencies and versions used
SpringWolf 1.2.0 :

	<!-- Springwolf -->
	<dependency>
		<groupId>io.github.springwolf</groupId>
		<artifactId>springwolf-core</artifactId>
		<version>${version.springwolf}</version>
	</dependency>
	<dependency>
		<groupId>io.github.springwolf</groupId>
		<artifactId>springwolf-amqp</artifactId>
		<version>${version.springwolf}</version>
	</dependency>
	<dependency>
		<groupId>io.github.springwolf</groupId>
		<artifactId>springwolf-ui</artifactId>
		<version>${version.springwolf}</version>
	</dependency>
	<!-- Springwolf end -->

SpringWolf 1.4.0: same as above plus:

		<dependency>
			<groupId>io.github.springwolf</groupId>
			<artifactId>springwolf-amqp-binding</artifactId>
			<version>${version.springwolf}</version>
		</dependency>

Code example
No code example

Stack trace and error logs

I see multiple log messages like this :

2024-07-02 10:15:48.297  INFO [rapport-controle,,] 50188 --- [           main] i.g.s.c.a.c.e.w.DefaultSchemaWalker      : Failed to build example for schema: There is no name set for Schema: class StringSchema {
    class Schema {
        type: string
        format: null
        $ref: null
        description: null
        title: null
        multipleOf: null
        maximum: null
        exclusiveMaximum: null
        minimum: null
        exclusiveMinimum: null
        maxLength: null
        minLength: null
        pattern: null
        maxItems: null
        minItems: null
        uniqueItems: null
        maxProperties: null
        minProperties: null
        required: null
        not: null
        properties: null
        additionalProperties: null
        nullable: null
        readOnly: null
        writeOnly: null
        example: null
        externalDocs: null
        deprecated: null
        discriminator: null
        xml: null
    }
}

io.github.springwolf.core.asyncapi.components.examples.walkers.SchemaWalker$ExampleGeneratingException: There is no name set for Schema: class StringSchema {
    class Schema {
        type: string
        format: null
        $ref: null
        description: null
        title: null
        multipleOf: null
        maximum: null
        exclusiveMaximum: null
        minimum: null
        exclusiveMinimum: null
        maxLength: null
        minLength: null
        pattern: null
        maxItems: null
        minItems: null
        uniqueItems: null
        maxProperties: null
        minProperties: null
        required: null
        not: null
        properties: null
        additionalProperties: null
        nullable: null
        readOnly: null
        writeOnly: null
        example: null
        externalDocs: null
        deprecated: null
        discriminator: null
        xml: null
    }
}
	at io.github.springwolf.core.asyncapi.components.examples.walkers.DefaultSchemaWalker.lambda$fromSchema$0(DefaultSchemaWalker.java:60) ~[springwolf-core-1.4.0.jar:na]
	at java.base/java.util.Optional.orElseThrow(Optional.java:403) ~[na:na]
	at io.github.springwolf.core.asyncapi.components.examples.walkers.DefaultSchemaWalker.fromSchema(DefaultSchemaWalker.java:59) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.components.postprocessors.ExampleGeneratorPostProcessor.process(ExampleGeneratorPostProcessor.java:26) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.schemas.SwaggerSchemaService.postProcessSchema(SwaggerSchemaService.java:210) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.schemas.SwaggerSchemaService.extractSchema(SwaggerSchemaService.java:89) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.components.DefaultComponentsService.registerSchema(DefaultComponentsService.java:51) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.scanners.common.payload.internal.PayloadService.buildSchema(PayloadService.java:35) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.scanners.common.payload.internal.PayloadService.buildSchema(PayloadService.java:31) ~[springwolf-core-1.4.0.jar:na]
	at java.base/java.util.Optional.map(Optional.java:260) ~[na:na]
	at io.github.springwolf.core.asyncapi.scanners.common.payload.PayloadMethodParameterService.extractSchema(PayloadMethodParameterService.java:19) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.scanners.operations.annotations.SpringAnnotationMethodLevelOperationsScanner.mapMethodToOperation(SpringAnnotationMethodLevelOperationsScanner.java:77) ~[springwolf-core-1.4.0.jar:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179) ~[na:na]
	at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:992) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276) ~[na:na]
	at java.base/java.util.HashMap$KeySpliterator.forEachRemaining(HashMap.java:1707) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:575) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluateToArrayNode(AbstractPipeline.java:260) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:616) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:622) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.toList(ReferencePipeline.java:627) ~[na:na]
	at io.github.springwolf.core.asyncapi.scanners.operations.SpringAnnotationOperationsScanner.mapToOperations(SpringAnnotationOperationsScanner.java:31) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.scanners.operations.SpringAnnotationOperationsScanner.scan(SpringAnnotationOperationsScanner.java:25) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.operations.DefaultOperationsService.findOperations(DefaultOperationsService.java:34) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.DefaultAsyncApiService.initAsyncAPI(DefaultAsyncApiService.java:71) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.asyncapi.DefaultAsyncApiService.getAsyncAPI(DefaultAsyncApiService.java:42) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.SpringwolfInitApplicationListener.onApplicationEvent(SpringwolfInitApplicationListener.java:31) ~[springwolf-core-1.4.0.jar:na]
	at io.github.springwolf.core.SpringwolfInitApplicationListener.onApplicationEvent(SpringwolfInitApplicationListener.java:17) ~[springwolf-core-1.4.0.jar:na]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.doInvokeListener(SimpleApplicationEventMulticaster.java:178) ~[spring-context-5.3.31.jar:5.3.31]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:171) ~[spring-context-5.3.31.jar:5.3.31]
	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:145) ~[spring-context-5.3.31.jar:5.3.31]
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:429) ~[spring-context-5.3.31.jar:5.3.31]
	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:386) ~[spring-context-5.3.31.jar:5.3.31]
	at org.springframework.boot.context.event.EventPublishingRunListener.ready(EventPublishingRunListener.java:114) ~[spring-boot-2.7.18.jar:2.7.18]
	at org.springframework.boot.SpringApplicationRunListeners.lambda$ready$6(SpringApplicationRunListeners.java:82) ~[spring-boot-2.7.18.jar:2.7.18]
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511) ~[na:na]
	at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:120) ~[spring-boot-2.7.18.jar:2.7.18]
	at org.springframework.boot.SpringApplicationRunListeners.doWithListeners(SpringApplicationRunListeners.java:114) ~[spring-boot-2.7.18.jar:2.7.18]
	at org.springframework.boot.SpringApplicationRunListeners.ready(SpringApplicationRunListeners.java:82) ~[spring-boot-2.7.18.jar:2.7.18]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:323) ~[spring-boot-2.7.18.jar:2.7.18]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1300) ~[spring-boot-2.7.18.jar:2.7.18]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1289) ~[spring-boot-2.7.18.jar:2.7.18]

[sam0r040]

Hi @pdalfarr,
thank you for the report.
For us it is difficult to reproduce this without the class for the schema.
Please enable debug mode to finde the method that includes the problematic payload and share the code for the payload with us.

[ruskaof]

Hello, @sam0r040
I've found code that can generate the problematic payload:

public record MyRootObject(
    MyEnumObject myEnumObject
) {
}

@Schema(enumAsRef = true)
public enum MyEnumObject {
    VALUE1,
    VALUE2
}

@Component
public class Producer {
    @AsyncPublisher(operation = @AsyncOperation(channelName = "mychannel"))
    public void produce(MyRootObject message) {
    }
}

The problem is that schema name for MyEnumObject is resolved to null and thus DefaultShemaWalker throws an exception here https://github.com/springwolf/springwolf-core/blob/master/springwolf-core/src/main/java/io/github/springwolf/core/asyncapi/components/examples/walkers/DefaultSchemaWalker.java#L61

Also, if you remove the wrapper class MyRootObject and return MyEnumObject itself in the produce() method no exception is thrown but no example for MyEnumObject is generated.

[timonback]

Hi @pdalfarr , @ruskaof,
I reproduced it with your code in #887

I do see the (unexpected) exception: There is no name set...
MyRootObject does have a valid example, MyEnumObject is missing one.

Do you expect an example for MyEnumObject and/or no exception?
Will keep looking into it.

[ruskaof]

I think that there should not be an exception thrown because schema name should be generated from a class name if it is not defined explicitly in the @Schema annotation. Also, it would be nice to have the enum class with its values referenced in the Schemas section of the UI. Something like springdoc generates with REST endpoints: