Have Spock fail a data-driven feature if an iteration fails - spock

Question

Is there a way to do the equivalent of #Stepwise's failure behavior for a single feature? We have some integration tests that are set up such that setupSpec() kicks off a Kafka process, and then the actual test checks that each step happened. If step 3 failed, there's no reason to bother checking subsequent steps.

Answer 1

There is no built-in way to do this, but assuming you are using a recent 2.x Spock version and not 1.3 or so, a relatively simple annotation-driven Spock extension can do the trick for you.
package de.scrum_master.stackoverflow.q71414311
import org.spockframework.runtime.extension.ExtensionAnnotation
import java.lang.annotation.ElementType
import java.lang.annotation.Retention
import java.lang.annotation.RetentionPolicy
import java.lang.annotation.Target
#Retention(RetentionPolicy.RUNTIME)
#Target(ElementType.METHOD)
#ExtensionAnnotation(StepwiseIterationsExtension)
#interface StepwiseIterations {}
package de.scrum_master.stackoverflow.q71414311
import org.spockframework.runtime.extension.IAnnotationDrivenExtension
import org.spockframework.runtime.model.FeatureInfo
import org.spockframework.runtime.model.parallel.ExecutionMode
class StepwiseIterationsExtension implements IAnnotationDrivenExtension<StepwiseIterations> {
#Override
void visitFeatureAnnotation(StepwiseIterations annotation, FeatureInfo feature) {
// Disable parallel iteration execution for #StepwiseIterations feature,
// similarly to how #Stepwise disables it for the whole specification
feature.setExecutionMode(ExecutionMode.SAME_THREAD)
// If an error occurs in this feature, skip remaining iterations
feature.getFeatureMethod().addInterceptor({ invocation ->
try {
invocation.proceed()
}
catch (Throwable t) {
invocation.getFeature().skip("skipping subsequent iterations after failure")
throw t
}
})
}
}
Add this to your code base, annotate your iterated test with #StepwiseIterations and run it. I think the result is exactly what you are looking for.
In Spock 1.3, an similar, but more complex extension would also be possible.
I also want to express my special thanks to Leonard Brünings, Spock maintainer and boundless source of knowledge. I had a more complex version of this extension in place, but after discussing with him, it evolved into this tiny, elegant solution we are seeing here.
FYI, there is a pre-existing Spock issue #1008 requesting this feature. I created pull request #1442 which adds this capability to #Stepwise. So hopefully in the future we do not need an extra annotation and extra extension anymore.