[CASSANDRA-21396][trunk] A test emitting both a failure and error element in the same JUnit XML testcase crashes CI summary generation

test/unit/org/apache/cassandra/CassandraXMLJUnitResultFormatter.java

@@ -338,14 +338,35 @@ private void formatError(final String type, final Test test, final Throwable t)
             failedTests.put(test, test);
         }
 
-        final Element nested = doc.createElement(type);
         Element currentTest;
         if (test != null) {
             currentTest = testElements.get(createDescription(test));
         } else {
             currentTest = rootElement;
         }
 
+        // A test can trigger both addFailure and addError (e.g. assertion failure during the test
+        // body followed by an error during teardown). The JUnit XML spec allows only one status
+        // child per <testcase>, so if one already exists we append the new message to it rather
+        // than adding a second child element (which would break XML parsers that enforce this rule).
+        Element existing = (Element) currentTest.getElementsByTagName(FAILURE).item(0);
+        if (existing == null)
+            existing = (Element) currentTest.getElementsByTagName(ERROR).item(0);
+
+        if (existing != null)
+        {
+            final String message = t.getMessage();
+            if (message != null && message.length() > 0)
+            {
+                String prev = existing.getAttribute(ATTR_MESSAGE);
+                existing.setAttribute(ATTR_MESSAGE, prev.isEmpty() ? message : prev + " | " + message);
+            }
+            final String strace = JUnitTestRunner.getFilteredTrace(t);
+            existing.appendChild(doc.createTextNode("\n--- additional error ---\n" + strace));
+            return;
+        }
+
+        final Element nested = doc.createElement(type);
         currentTest.appendChild(nested);
 
         final String message = t.getMessage();

test/unit/org/apache/cassandra/CassandraXMLJUnitResultFormatterTest.java

@@ -0,0 +1,164 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.cassandra;
+
+import java.io.ByteArrayOutputStream;
+
+import javax.xml.parsers.DocumentBuilderFactory;
+
+import org.apache.tools.ant.taskdefs.optional.junit.JUnitTest;
+import org.junit.Before;
+import org.junit.Test;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.NodeList;
+
+import junit.framework.AssertionFailedError; // checkstyle: permit this import
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+public class CassandraXMLJUnitResultFormatterTest
+{
+    private static final DocumentBuilderFactory DOCUMENT_BUILDER_FACTORY = DocumentBuilderFactory.newInstance();
+
+    // Minimal junit.framework.Test implementation used to drive the formatter.
+    private static class FakeTest implements junit.framework.Test
+    {
+        private final String className;
+        private final String methodName;
+
+        FakeTest(String className, String methodName)
+        {
+            this.className = className;
+            this.methodName = methodName;
+        }
+
+        @Override
+        public int countTestCases() { return 1; }
+
+        @Override
+        public void run(junit.framework.TestResult result) {}
+
+        // Providing toString() in JUnit3 name-extraction format: "methodName(className)"
+        @Override
+        public String toString() { return methodName + "(" + className + ")"; }
+    }
+
+    private CassandraXMLJUnitResultFormatter formatter;
+    private ByteArrayOutputStream out;
+
+    @Before
+    public void setUp()
+    {
+        formatter = new CassandraXMLJUnitResultFormatter();
+        out = new ByteArrayOutputStream();
+        formatter.setOutput(out);
+        JUnitTest suite = new JUnitTest("org.apache.cassandra.SomeTest");
+        formatter.startTestSuite(suite);
+    }
+
+    /**
+     * Regression test for CASSANDRA-21396: when both addFailure and addError are called for the
+     * same test (e.g. assertion failure in test body + error during teardown), the formatter must
+     * emit exactly one status child element under testcase section rather than two.
+     * Having two status children violates the JUnit XML spec and breaks ci_summary.html generation.
+     * Both messages must be preserved in the surviving element's message attribute.
+     */
+    @Test
+    public void testFailureThenErrorProducesOneStatusChild() throws Exception
+    {
+        FakeTest test = new FakeTest("org.apache.cassandra.SomeTest", "someTestMethod");
+
+        formatter.startTest(test);
+        formatter.addFailure(test, new AssertionFailedError("first failure message"));
+        formatter.addError(test, new RuntimeException("second error message"));
+        formatter.endTest(test);
+
+        JUnitTest suite = new JUnitTest("org.apache.cassandra.SomeTest");
+        suite.setCounts(1, 1, 1, 0);
+        formatter.endTestSuite(suite);
+
+        Document doc = parseOutput();
+        NodeList testcases = doc.getElementsByTagName("testcase");
+        assertEquals("Expected exactly one testcase element", 1, testcases.getLength());
+
+        Element testcase = (Element) testcases.item(0);
+        NodeList failures = testcase.getElementsByTagName("failure");
+        NodeList errors = testcase.getElementsByTagName("error");
+        int totalStatusChildren = failures.getLength() + errors.getLength();
+        assertEquals("Expected exactly one status child element (failure or error) per testcase", 1, totalStatusChildren);
+
+        Element statusElem = (Element) (failures.getLength() > 0 ? failures.item(0) : errors.item(0));
+        String message = statusElem.getAttribute("message");
+        assertTrue("message should contain first failure text", message.contains("first failure message"));
+        assertTrue("message should contain second error text", message.contains("second error message"));
+    }
+
+    @Test
+    public void testSingleFailureIsUnchanged() throws Exception
+    {
+        FakeTest test = new FakeTest("org.apache.cassandra.SomeTest", "someTestMethod");
+
+        formatter.startTest(test);
+        formatter.addFailure(test, new AssertionFailedError("only failure"));
+        formatter.endTest(test);
+
+        JUnitTest suite = new JUnitTest("org.apache.cassandra.SomeTest");
+        suite.setCounts(1, 1, 0, 0);
+        formatter.endTestSuite(suite);
+
+        Document doc = parseOutput();
+        Element testcase = (Element) doc.getElementsByTagName("testcase").item(0);
+        NodeList failures = testcase.getElementsByTagName("failure");
+        NodeList errors = testcase.getElementsByTagName("error");
+
+        assertEquals("Expected one failure element", 1, failures.getLength());
+        assertEquals("Expected no error element", 0, errors.getLength());
+        assertEquals("only failure", ((Element) failures.item(0)).getAttribute("message"));
+    }
+
+    @Test
+    public void testPassedTestHasNoStatusChild() throws Exception
+    {
+        FakeTest test = new FakeTest("org.apache.cassandra.SomeTest", "someTestMethod");
+
+        formatter.startTest(test);
+        formatter.endTest(test);
+
+        JUnitTest suite = new JUnitTest("org.apache.cassandra.SomeTest");
+        suite.setCounts(1, 0, 0, 0);
+        formatter.endTestSuite(suite);
+
+        Document doc = parseOutput();
+        Element testcase = (Element) doc.getElementsByTagName("testcase").item(0);
+        NodeList failures = testcase.getElementsByTagName("failure");
+        NodeList errors = testcase.getElementsByTagName("error");
+        NodeList skipped = testcase.getElementsByTagName("skipped");
+
+        assertEquals(0, failures.getLength());
+        assertEquals(0, errors.getLength());
+        assertEquals(0, skipped.getLength());
+    }
+
+    private Document parseOutput() throws Exception
+    {
+        return DOCUMENT_BUILDER_FACTORY.newDocumentBuilder().parse(new java.io.ByteArrayInputStream(out.toByteArray()));
+    }
+}