Add temporary ErrorSpecNode until it is handled by the platform

Author: leonard84

Diff for: spock-core/src/main/java/org/spockframework/runtime/ClassSelectorResolver.java

@@ -49,7 +49,12 @@ private Resolution resolveClass(Class<?> specClass, Context context) {
       return context
         .addToParent(parent -> {
           UniqueId uniqueId = parent.getUniqueId().append("spec", specInfo.getReflection().getName());
-          runContext.createExtensionRunner(specInfo).run();
+          try {
+            runContext.createExtensionRunner(specInfo).run();
+          } catch (Exception e) {
+            // TODO revisit, this should be handled on the platform level
+            return Optional.of(new ErrorSpecNode(uniqueId, specInfo, e));
+          }
           return Optional.of(new SpecNode(uniqueId, specInfo));
         })
         .map(specNode -> toResolution(specInfo, specNode))

Diff for: spock-core/src/main/java/org/spockframework/runtime/ErrorSpecNode.java

@@ -0,0 +1,21 @@
+package org.spockframework.runtime;
+
+import org.spockframework.runtime.model.SpecInfo;
+import org.spockframework.util.ExceptionUtil;
+
+import org.junit.platform.engine.UniqueId;
+
+public class ErrorSpecNode extends SpecNode {
+  private final Throwable error;
+
+  protected ErrorSpecNode(UniqueId uniqueId, SpecInfo specInfo, Throwable error) {
+    super(uniqueId, specInfo);
+    this.error = error;
+  }
+
+  @Override
+  public SpockExecutionContext execute(SpockExecutionContext context, DynamicTestExecutor dynamicTestExecutor) throws Exception {
+    ExceptionUtil.sneakyThrow(error);
+    return null; //
+  }
+}