Verify JUnit no tests shadowing

testing/trino-testing-services/src/main/java/io/trino/testing/services/junit/ReportOverriddenMethods.java

@@ -0,0 +1,71 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.trino.testing.services.junit;
+
+import org.junit.platform.engine.support.descriptor.MethodSource;
+import org.junit.platform.launcher.TestExecutionListener;
+import org.junit.platform.launcher.TestIdentifier;
+import org.junit.platform.launcher.TestPlan;
+
+import java.lang.reflect.Modifier;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Stream;
+
+import static com.google.common.base.Throwables.getStackTraceAsString;
+import static io.trino.testing.services.junit.Listeners.reportListenerFailure;
+import static java.lang.String.format;
+
+public class ReportOverriddenMethods
+        implements TestExecutionListener
+{
+    @Override
+    public void testPlanExecutionStarted(TestPlan testPlan)
+    {
+        try {
+            testPlan.accept(new TestPlan.Visitor()
+            {
+                @Override
+                public void visit(TestIdentifier testIdentifier)
+                {
+                    testIdentifier.getSource().ifPresent(source -> {
+                        if (source instanceof MethodSource methodSource) {
+                            if (!Modifier.isPublic(methodSource.getJavaMethod().getModifiers()) &&
+                                    !Modifier.isProtected(methodSource.getJavaMethod().getModifiers())) {
+                                List<Class<?>> declaringClasses = Stream.<Class<?>>iterate(methodSource.getJavaClass(), clazz -> clazz.getSuperclass() != null, Class::getSuperclass)
+                                        .filter(clazz ->
+                                                Arrays.stream(clazz.getDeclaredMethods())
+                                                        .anyMatch(method -> method.getName().equals(methodSource.getJavaMethod().getName())))
+                                        .toList();
+                                if (declaringClasses.size() > 1) {
+                                    throw new IllegalStateException(format(
+                                            """
+                                                    Method %s is not public. Similar methods are defined by %s. \
+                                                    When tests are non-public, they do not @Override in Java sense, but they still interact with each other in JUnit, \
+                                                    and only one of declared tests gets executed. \
+                                                    This leads to tests being silently skipped without any source-level indication.""",
+                                            methodSource.getJavaMethod(),
+                                            declaringClasses));
+                                }
+                            }
+                        }
+                    });
+                }
+            });
+        }
+        catch (RuntimeException | Error e) {
+            reportListenerFailure(getClass(), "%s", getStackTraceAsString(e));
+        }
+    }
+}

testing/trino-testing-services/src/main/resources/META-INF/services/org.junit.platform.launcher.TestExecutionListener

@@ -1 +1,2 @@
 io.trino.testing.services.junit.LogTestDurationListener
+io.trino.testing.services.junit.ReportOverriddenMethods