Merge pull request #1401 from hcoles/feature/junt4_error_loggins

extract errors when JUnit4 classes cannot be loaded

Author: hcoles

pitest/src/main/java/org/pitest/junit/DebugListener.java

@@ -0,0 +1,33 @@
+package org.pitest.junit;
+
+import org.junit.runner.notification.Failure;
+import org.junit.runner.notification.RunListener;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+/**
+ * Extracts failure strings from junit error runners
+ * Currently only for initialisation errors
+ */
+public class DebugListener extends RunListener {
+    private final List<String> problems = new ArrayList<>();
+
+   @Override
+    public void testFailure(Failure failure) {
+       String exception = failure.getException().toString();
+       if (exception.contains("NoClassDefFoundError") || exception.contains("ClassNotFoundException")) {
+           problems.add(exception + "\n" + failure.getTrace());
+       }
+
+    }
+
+    public Optional<String> problems() {
+       if (problems.isEmpty()) {
+           return Optional.empty();
+       }
+       return Optional.of(String.join("\n",problems));
+    }
+
+}

pitest/src/main/java/org/pitest/junit/JUnitCustomRunnerTestUnitFinder.java

@@ -36,6 +36,7 @@
 import org.junit.runner.Runner;
 import org.junit.runner.manipulation.Filter;
 import org.junit.runner.manipulation.Filterable;
+import org.junit.runner.notification.RunNotifier;
 import org.junit.runners.Parameterized;
 import org.pitest.functional.FCollection;
 import org.pitest.junit.adapter.AdaptedJUnitTestUnit;
@@ -46,6 +47,7 @@
 import org.pitest.testapi.TestUnitExecutionListener;
 import org.pitest.testapi.TestUnitFinder;
 import org.pitest.util.IsolationUtils;
+import org.pitest.util.Log;
 
 public class JUnitCustomRunnerTestUnitFinder implements TestUnitFinder {
 
@@ -71,6 +73,9 @@ public List<TestUnit> findTestUnits(final Class<?> clazz, TestUnitExecutionListe
     final Runner runner = AdaptedJUnitTestUnit.createRunner(clazz);
 
     if (isExcluded(runner) || isNotARunnableTest(runner, clazz.getName()) || !isIncluded(clazz)) {
+      if (Log.verbosity().showMinionOutput() && runner instanceof ErrorReportingRunner) {
+        showJUnitErrors(clazz, runner);
+      }
       return Collections.emptyList();
     }
 
@@ -84,6 +89,14 @@ public List<TestUnit> findTestUnits(final Class<?> clazz, TestUnitExecutionListe
     }
   }
 
+  private void showJUnitErrors(Class<?> clazz, Runner runner) {
+    RunNotifier notifier = new RunNotifier();
+    DebugListener debugListener = new DebugListener();
+    notifier.addListener(debugListener);
+    runner.run(notifier);
+    Log.getLogger().fine("Cannot find tests in " + clazz + " : " + debugListener.problems());
+  }
+
   private List<TestUnit> filterUnitsByMethod(List<TestUnit> filteredUnits) {
     if (this.includedTestMethods.isEmpty()) {
       return filteredUnits;

pitest/src/test/java/org/pitest/junit/DebugListenerTest.java

@@ -0,0 +1,34 @@
+package org.pitest.junit;
+
+import org.junit.Test;
+
+import org.junit.runner.notification.Failure;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class DebugListenerTest {
+    DebugListener testee = new DebugListener();
+
+    @Test
+    public void reportsErrorsWhenNoClassDefFound() {
+        testee.testFailure(new Failure(null, new Exception("NoClassDefFoundError")));
+        assertThat(testee.problems()).isPresent();
+        assertThat(testee.problems().get()).contains("NoClassDefFoundError");
+        assertThat(testee.problems().get()).contains("at org.pitest.junit.DebugListenerTest");
+    }
+
+    @Test
+    public void reportsErrorsWhenClassNotFound() {
+        testee.testFailure(new Failure(null, new Exception("ClassNotFoundException")));
+        assertThat(testee.problems()).isPresent();
+        assertThat(testee.problems().get()).contains("ClassNotFoundException");
+        assertThat(testee.problems().get()).contains("at org.pitest.junit.DebugListenerTest");
+    }
+
+    @Test
+    public void doesNotReportErrorsForOtherExceptions() {
+        testee.testFailure(new Failure(null, new Exception("foo bar")));
+        assertThat(testee.problems()).isEmpty();
+    }
+
+}