file("src/main/java/SomeClass.java") << """
            @Helper class SomeClass {}
        """
        def processorProjectDir = file("processor")
        def fixture = new HelperProcessorFixture()
        fixture.writeApiTo(processorProjectDir)
        fixture.writeAnnotationProcessorTo(processorProjectDir)
        fixture.writeSupportLibraryTo(processorProjectDir)
    }

    @Issue("https://github.com/gradle/gradle/issues/22999")

        this.annotationPackageName = annotationPackageName
        this.fqAnnotationName = annotationPackageName.empty ? annotationName : "${annotationPackageName}.${annotationName}"
    }

    final void writeApiTo(TestFile projectDir) {
        def packagePathPrefix = annotationPackageName.empty ? '' : "${annotationPackageName.replace('.', '/')}/"

                    classpath = sourceSets.main.runtimeClasspath
                }
            }
        """

        def fixture = new HelperProcessorFixture()

        // The annotation
        fixture.writeApiTo(file("a"))

        // The processor and library
        fixture.writeSupportLibraryTo(file("b"))
        fixture.writeAnnotationProcessorTo(file("b"))

        // The class that is the target of the processor

            }
        """
    }

    protected void withProcessor(AnnotationProcessorFixture processor) {
        processor.writeSupportLibraryTo(libraryProjectDir)
        processor.writeApiTo(annotationProjectDir)
        processor.writeAnnotationProcessorTo(processorProjectDir)
    }

    protected final File java(@Language("java") String... classBodies) {
        javaInPackage('', classBodies)
    }

        file("src/main/java/SomeClass.java") << """
            @Helper class SomeClass {}
        """
        def processorProjectDir = file("processor")
        def fixture = new HelperProcessorFixture()
        fixture.writeApiTo(processorProjectDir)
        fixture.writeAnnotationProcessorTo(processorProjectDir)
        fixture.writeSupportLibraryTo(processorProjectDir)
    }

    @TargetGradleVersion(">=5.1")

        """

        // A library class used by processor at runtime, but not the generated classes
        fixture.writeSupportLibraryTo(processorProjectDir)

        // The processor and annotation
        fixture.writeApiTo(annotationProjectDir)
        fixture.writeAnnotationProcessorTo(processorProjectDir)

        // The class that is the target of the processor
        file('src/main/java/TestApp.java') << '''
            @Helper