OutsideJqwikException on simple test case after 1.5.0 upgrade-CodePudding

Testing Problem

I wrote the following sample code and run it on intelliJ and kept getting the same exception on v1.5.0 . The same code works fine on 1.4.0 and lower...

This is the sample code I reduced my actual test code down to:

import java.util.Random;
import net.jqwik.api.Arbitraries;
import net.jqwik.api.Arbitrary;
import net.jqwik.api.Combinators;

public class Test {

    public static Arbitrary<String> testing() {
        return Combinators.withBuilder(StringBuilder::new)
            .use(Arbitraries.of("123")).in(StringBuilder::append)
            .build(StringBuilder::toString);
    }

    @org.junit.jupiter.api.Test
    public void test() {
        testing().generator(0).next(new Random()).value();
    }
}

Stacktrace:

net.jqwik.engine.execution.lifecycle.OutsideJqwikException: The current action must be run on a jqwik thread, i.e. container, property or hook.
Maybe you spawned off a thread?

    at net.jqwik.engine.execution.lifecycle.CurrentTestDescriptor.get(CurrentTestDescriptor.java:50)
    at net.jqwik.engine.facades.StoreFacadeImpl.get(StoreFacadeImpl.java:24)
    at net.jqwik.api.lifecycle.Store.get(Store.java:92)
    at net.jqwik.api.lifecycle.Store.getOrCreate(Store.java:68)
    at net.jqwik.engine.facades.Memoize.generatorStore(Memoize.java:13)
    at net.jqwik.engine.facades.Memoize.memoizedGenerator(Memoize.java:26)
    at net.jqwik.engine.facades.ArbitraryFacadeImpl.memoizedGenerator(ArbitraryFacadeImpl.java:221)
    at net.jqwik.api.Arbitrary.generator(Arbitrary.java:92)
    at net.jqwik.api.Combinators$Combinator2$1.rawGenerator(Combinators.java:264)
    at net.jqwik.api.Combinators$Combinator2$1.generator(Combinators.java:255)
    at net.jqwik.engine.facades.ArbitraryFacadeImpl$2.generator(ArbitraryFacadeImpl.java:79)
    at com.test.my.code.project.Test.test(Test.java:18)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:566)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:688)
    at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
    at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
    at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:210)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:206)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:131)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:65)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at org.junit.platform.engine.support.hierarchical.ForkJoinPoolHierarchicalTestExecutorService$ExclusiveTask.compute(ForkJoinPoolHierarchicalTestExecutorService.java:185)
    at org.junit.platform.engine.support.hierarchical.ForkJoinPoolHierarchicalTestExecutorService.invokeAll(ForkJoinPoolHierarchicalTestExecutorService.java:129)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at org.junit.platform.engine.support.hierarchical.ForkJoinPoolHierarchicalTestExecutorService$ExclusiveTask.compute(ForkJoinPoolHierarchicalTestExecutorService.java:185)
    at org.junit.platform.engine.support.hierarchical.ForkJoinPoolHierarchicalTestExecutorService.invokeAll(ForkJoinPoolHierarchicalTestExecutorService.java:129)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
    at org.junit.platform.engine.support.hierarchical.ForkJoinPoolHierarchicalTestExecutorService$ExclusiveTask.compute(ForkJoinPoolHierarchicalTestExecutorService.java:185)
    at java.base/java.util.concurrent.RecursiveAction.exec(RecursiveAction.java:189)
    at java.base/java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:290)
    at java.base/java.util.concurrent.ForkJoinPool$WorkQueue.topLevelExec(ForkJoinPool.java:1020)
    at java.base/java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1656)
    at java.base/java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1594)
    at java.base/java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:183)


Process finished with exit code 255

Removing the .use(Arbitraries.of("123")).in(StringBuilder::append) will make the test pass, so the exception is coming from the generate(int).
Changing to .example or marking with @Example seems to also help as well, but I dont think I need to do that given that is a new issue after upgrading.

CodePudding user response：

Using generators in the way you do is no longer supported by jqwik. Instead, you have to use: Arbitrary.sample() or Arbitrary.sampleStream() for generating values outside of @Property or @Example methods:

@org.junit.jupiter.api.Test
public void test() {
    testing().sample();
}

The reason is that efficiently generating values requires quite some statefule machinery under the hood. You should read https://jqwik.net/docs/current/user-guide.html#using-arbitraries-directly and especially https://jqwik.net/docs/current/user-guide.html#using-arbitraries-outside-jqwik-lifecycle for more guidance.

Moreover, use at least version 1.5.6 of jqwik or - even better - the most recent 1.6.1.

Another question that comes to mind is: Why do you want to generate samples yourself and not use jqwik's lifecycle? There are a few valid reasons for that, but standard use cases already are covered by @Example and @Property.