wicket-scala unit tests fail with maven-surefire-plugin 2.9

[akiraly]

I tried to update the maven-surefire-plugin from 2.6 to 2.9 but the wicket-scala unit tests (written in scala) failed with the new version. The cause for the exception seems to be a class loader problem: o.a.w.application.AbstractClassResolver.resolveClass(AbstractClassResolver.java:110) does not find o.a.w.Initializer class.

Exception snippet:

166 [main] WARN org.apache.wicket.util.lang.WicketObjects - Could not resolve class [org.apache.wicket.Initializer]
java.lang.ClassNotFoundException: org.apache.wicket.Initializer
    at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:268)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:242)
    at org.apache.wicket.application.AbstractClassResolver.resolveClass(AbstractClassResolver.java:110)
    at org.apache.wicket.util.lang.WicketObjects.resolveClass(WicketObjects.java:68)
    at org.apache.wicket.util.lang.WicketObjects.newInstance(WicketObjects.java:376)
    at org.apache.wicket.Application.addInitializer(Application.java:577)
    at org.apache.wicket.Application.load(Application.java:615)
    at org.apache.wicket.Application.initializeComponents(Application.java:501)
    at org.apache.wicket.Application.initApplication(Application.java:806)
    at org.apache.wicket.util.tester.BaseWicketTester.<init>(BaseWicketTester.java:295)
    at org.apache.wicket.util.tester.BaseWicketTester.<init>(BaseWicketTester.java:239)
    at org.apache.wicket.util.tester.BaseWicketTester.<init>(BaseWicketTester.java:209)
    at org.apache.wicket.util.tester.WicketTester.<init>(WicketTester.java:170)
    at org.wicketstuff.scala.ComponentSpecs$$anonfun$4$$anonfun$apply$9.apply(ComponentSpecs.scala:41)
    at org.wicketstuff.scala.ComponentSpecs$$anonfun$4$$anonfun$apply$9.apply(ComponentSpecs.scala:41)
    at org.specs.specification.BeforeAfter$$anonfun$stackActions$1.apply(Context.scala:81)
    at org.specs.specification.ExampleContext$$anonfun$executeActions$1$$anonfun$apply$1.apply(ExampleContext.scala:59)
    at org.specs.specification.LifeCycle$class.withCurrent(ExampleLifeCycle.scala:66)
    at org.specs.specification.Examples.withCurrent(Examples.scala:52)
    at org.specs.specification.ExampleContext$$anonfun$executeActions$1.apply(ExampleContext.scala:59)
    at org.specs.specification.ExampleContext$$anonfun$executeActions$1.apply(ExampleContext.scala:58)
    at scala.Option.map(Option.scala:134)
    at org.specs.specification.ExampleContext$class.executeActions(ExampleContext.scala:58)
    at org.specs.specification.ExampleContext$class.beforeExample(ExampleContext.scala:53)
    at org.specs.specification.Examples.beforeExample(Examples.scala:52)
    at org.specs.specification.ExampleContext$$anonfun$beforeExample$2.apply(ExampleContext.scala:48)
    at org.specs.specification.ExampleContext$$anonfun$beforeExample$2.apply(ExampleContext.scala:48)
    at scala.Option.map(Option.scala:134)
    at org.specs.specification.ExampleContext$class.beforeExample(ExampleContext.scala:48)
    at org.specs.specification.Examples.beforeExample(Examples.scala:52)
    at org.specs.specification.ExampleExecution$$anonfun$3.apply(ExampleLifeCycle.scala:201)
    at org.specs.specification.ExampleExecution$$anonfun$3.apply(ExampleLifeCycle.scala:198)
    at org.specs.specification.ExampleExecution$$anonfun$2.apply(ExampleLifeCycle.scala:181)
    at org.specs.specification.ExampleExecution.execute(ExampleLifeCycle.scala:252)
    at org.specs.specification.SpecificationExecutor$$anonfun$executeExample$3.apply(SpecificationExecutor.scala:70)
    at org.specs.specification.SpecificationExecutor$$anonfun$executeExample$3.apply(SpecificationExecutor.scala:70)
    at scala.Option.map(Option.scala:134)
    at org.specs.specification.SpecificationExecutor$class.executeExample(SpecificationExecutor.scala:70)
    at org.specs.specification.BaseSpecification.executeExample(BaseSpecification.scala:58)
    at org.specs.specification.BaseSpecification.executeExample(BaseSpecification.scala:58)
    at org.specs.specification.ExampleLifeCycle$$anonfun$executeExample$1.apply(ExampleLifeCycle.scala:125)
    at org.specs.specification.ExampleLifeCycle$$anonfun$executeExample$1.apply(ExampleLifeCycle.scala:125)
    at scala.Option.map(Option.scala:134)
    at org.specs.specification.ExampleLifeCycle$class.executeExample(ExampleLifeCycle.scala:125)
    at org.specs.specification.Examples.executeExample(Examples.scala:52)
    at org.specs.specification.Examples.executeExample(Examples.scala:52)
    at org.specs.specification.Examples$$anonfun$executeExamples$2.apply(Examples.scala:80)
    at org.specs.specification.Examples$$anonfun$executeExamples$2.apply(Examples.scala:80)
    at scala.Option.map(Option.scala:134)
    at org.specs.specification.Examples.executeExamples(Examples.scala:80)
    at org.specs.specification.ExampleStructure$class.ownSkipped(ExampleStructure.scala:60)
    at org.specs.specification.Examples.ownSkipped(Examples.scala:52)
    at org.specs.runner.ExampleTestCase.run(JUnit.scala:205)
    at junit.framework.TestSuite.runTest(TestSuite.java:243)
    at junit.framework.TestSuite.run(TestSuite.java:238)
    at org.specs.runner.JUnitSuite$class.run(JUnit.scala:62)
    at org.specs.runner.ExamplesTestSuite.run(JUnit.scala:167)
    at junit.framework.TestSuite.runTest(TestSuite.java:243)
    at junit.framework.TestSuite.run(TestSuite.java:238)
    at org.specs.runner.JUnitSuite$class.run(JUnit.scala:62)
    at org.specs.SpecificationWithJUnit.run(SpecificationWithJUnit.scala:29)
    at org.specs.runner.JUnitSuiteRunner.run(JUnitSuiteRunner.scala:45)
    at org.apache.maven.surefire.junit4.JUnit4TestSet.execute(JUnit4TestSet.java:53)
    at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:123)
    at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:104)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:592)
    at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:164)
    at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:110)
    at org.apache.maven.surefire.booter.SurefireStarter.invokeProvider(SurefireStarter.java:172)
    at org.apache.maven.surefire.booter.SurefireStarter.runSuitesInProcessWhenForked(SurefireStarter.java:104)
    at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:70) 

[akiraly]

The two different versions of surefire set different classloaders as current thread context classloader.

Surefire 2.6 uses org.apache.maven.surefire.booter.IsolatedClassLoader (note Isolated...) which has the following jars in it:
[/workspace-wicketstuff/core/jdk-1.5-parent/scala-extensions-parent/wicket-scala/target/test-classes/, /workspace-wicketstuff/core/jdk-1.5-parent/scala-extensions-parent/wicket-scala/target/classes/, /mvnrepo/org/scala-lang/scala-library/2.9.0-1/scala-library-2.9.0-1.jar, /mvnrepo/javax/servlet/servlet-api/2.5/servlet-api-2.5.jar, /mvnrepo/org/scala-tools/testing/specs_2.9.0-1/1.6.8/specs_2.9.0-1-1.6.8.jar, /mvnrepo/org/scala-lang/scala-compiler/2.9.0-1/scala-compiler-2.9.0-1.jar, /mvnrepo/org/scalatest/scalatest/1.3/scalatest-1.3.jar, /mvnrepo/junit/junit/4.8.2/junit-4.8.2.jar, /mvnrepo/org/slf4j/slf4j-simple/1.6.1/slf4j-simple-1.6.1.jar, /mvnrepo/org/slf4j/slf4j-api/1.6.1/slf4j-api-1.6.1.jar, /mvnrepo/org/apache/wicket/wicket-core/1.5-SNAPSHOT/wicket-core-1.5-SNAPSHOT.jar, /mvnrepo/org/apache/wicket/wicket-util/1.5-SNAPSHOT/wicket-util-1.5-SNAPSHOT.jar, /mvnrepo/org/apache/wicket/wicket-request/1.5-SNAPSHOT/wicket-request-1.5-SNAPSHOT.jar]

But Surefire 2.9 uses sun.misc.Launcher$AppClassLoader which only has the following jars:
[/mvnrepo/org/apache/maven/surefire/surefire-booter/2.9/surefire-booter-2.9.jar, /mvnrepo/org/apache/maven/surefire/surefire-api/2.9/surefire-api-2.9.jar]

This means that with 2.9 the classloader loading for example org.apache.wicket.Application class is not the same as the classloader in the current thread context.

During tests wicket probably should either set the current thread context classloader (similarly how it is done in WicketFilter) or use a different IClassResolver (not DefaultClassResolver).

[akiraly]

Wicket jira issue for this: https://issues.apache.org/jira/browse/WICKET-3933

[martin-g]

Looks like Surefire bug to me.
Why all Maven dependencies are not in the classpath in 2.9 ?!

[martin-g]

Fixed with a66f335