[BUG] no test code generated for Java

Description

Despite correct options and reading the docs, no test sources are generated for valid yaml with the Java spring/spring-boot generator.

openapi-generator version

openapi-generator(-maven-plugin) 4.3.1

OpenAPI declaration file content or url

cannot post without confirmation from company, but models are generated just fine, only tests are missing.

Command line used for generation

Using Maven 3.6.1, AdoptOpenJDK 11.0.4 and version above.

Steps to reproduce

options used:

<configuration>
    <inputSpec>${project.basedir}/src/main/resources/openapi/my-api.yml</inputSpec>
    <generatorName>spring</generatorName>
    <apiPackage>at.my.api</apiPackage>
    <modelPackage>a.my.model</modelPackage>
    <configOptions>
        <dateLibrary>java8</dateLibrary>
        <library>spring-boot</library>
        <useOptional>true</useOptional>
        <useTags>true</useTags>
        <serializableModel>true</serializableModel>
        <booleanGetterPrefix>is</booleanGetterPrefix>
        <performBeanValidation>true</performBeanValidation>
        <useBeanValidation>true</useBeanValidation>
        <serializationLibrary>jackson</serializationLibrary>
        <additionalModelTypeAnnotations>
            @lombok.experimental.SuperBuilder
            @lombok.NoArgsConstructor
            @lombok.AllArgsConstructor
        </additionalModelTypeAnnotations>
    </configOptions>
</configuration>

Suggest a fix

quickly glanced the source of the Java generator and saw that api test folders are set, but did not check further.

The issue points to the Java generator, its API test folders, and the Maven plugin configuration for the spring-boot library. Start by inspecting the Java generator's test-generation templates and reproduce the problem with a minimal valid YAML, since the original specification is unavailable. Done means Java test sources are generated while model generation still works.