Cannot create Launcher without at least one TestEngine, but I think all the jars are in place

[paolopiccinini]

I'm trying to replicate a mockito bug where we are launching test via API for our integration tests. Anyway it has been hours that I'm struggling whit this exception
Cannot create Launcher without at least one TestEngine but I think all the jars are in place
I even putted the TestEngine implementation in my main package, added the dependency in WEB-INF/lib but nothing is working
LauncherFactory.collectTestEngines is unable to load the classes.

The deployment looks like this:
In wildfly we have a war that depends on a module that has the jars.

In the debugger is used this line of code ClassLoaderUtils.getDefaultClassLoader().packages.keySet().stream().filter(s -> s.startsWith("org.junit")).toList() with brackpoint on line 33 of ServiceLoaderTestEngineRegistry.loadTestEngines

But I get

Compilation failed:
package org.junit.platform.commons.util does not exist
package org.apiguardian.api.API does not exist
static import only from classes and interfaces
cannot find symbol
  symbol:   variable ClassLoaderUtils
  location: class idea.debugger.rt.GeneratedEvaluationClass

I don't know if this is useful.
U can find the complete docker example here with the steps to reproduce.
Is tehre some dependency that I'm missing? is it the wildfly classloader?

Any help is appreciated

[marcphilipp]

I suspect some snafu to be causing this. Unfortunately, I know nothing about Wildfly but maybe setting the thread context class loader for JUnit helps before calling LauncherFactory.create()?

Thread.currentThread().setContextClassLoader(getClass().getClassLoader());
Launcher launcher = LauncherFactory.create();
...

[paolopiccinini]

@marcphilipp nope that didn't help. The fact is that when debugging I can see all the packages of spring in the ClassLoader the only ones missing are the junit one.

Can I ask a question why are u getting the test engine from the classloader?

anyway I was able to reproduce the bug so it is not so important, but will be interesting to understand what is going on.

I updated the README of the project to use maven in local to patch the jars so give a pull, and u can debug attaching a remote debugger to port 8787 if u are interested

[marcphilipp]

Can I ask a question why are u getting the test engine from the classloader?

We use the ServiceLoader mechanism to discover engines at runtime. That allows third-parties such as Spock and Cucumber to run tests on the JUnit Platform.

[paolopiccinini]

Finaly I got it, the implementation of the test engine is in junit-jupiter-engine and the war was not depending on it. So it's not able to see the module class loader but the war lives in it's own classloader.

Anyway this is strange all the classes are visible at runtime, only the class loading is failing

What is solving the proble are these dependency in the war

<dependency>
            <groupId>org.junit.platform</groupId>
            <artifactId>junit-platform-launcher</artifactId>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.platform</groupId>
                    <artifactId>junit-platform-engine</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.junit.platform</groupId>
                    <artifactId>junit-platform-commons</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.junit.platform</groupId>
                    <artifactId>junit-platform-launcher</artifactId>
                </exclusion>
            </exclusions>
        </dependency>