Failed TestTemplate with only one test doesn't show fail trace

This change adjusts TestSuiteElement to show the trace of a failed
child, if that child is the only test case it ran and its dynamic. It
also adjusts navigation to the failed line in this case - so that
navigation goes to the failed line and not to the test method with the
@testtemplate annotation.

Fixes: #1021
Signed-off-by: Simeon Andreev <simeon.danailov.andreev@gmail.com>

org.eclipse.jdt.junit.core/src/org/eclipse/jdt/internal/junit/model/TestSuiteElement.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2017 IBM Corporation and others.
+ * Copyright (c) 2000, 2023 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -156,6 +156,15 @@ public String toString() {
 		return "TestSuite: " + getTestName() + " : " + super.toString() + " (" + fChildren.size() + ")";   //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$
 	}
 
+	@Override
+	public String getTrace() {
+		TestCaseElement child= getSingleDynamicChild();
+		if (child != null) {
+			return child.getTrace();
+		}
+		return super.getTrace();
+	}
+
 	private static boolean isSingleDynamicTest(TestElement element) {
 		if (element instanceof TestCaseElement) {
 			TestCaseElement testCase = (TestCaseElement) element;
@@ -166,4 +175,25 @@ private static boolean isSingleDynamicTest(TestElement element) {
 		}
 		return false;
 	}
+
+	/**
+	 * If this test suite is a {@code @TestTemplate} test case with a single child, return that child.
+	 * @return The single dynamic test case child or {@code null} if the suite has no children or multiple or non-dynamid children.
+	 */
+	public TestCaseElement getSingleDynamicChild() {
+		try {
+			if (fChildren.size() == 1) {
+				TestElement child= fChildren.get(0);
+				if (child instanceof TestCaseElement) {
+					TestCaseElement testCase= (TestCaseElement) child;
+					if (testCase.isDynamicTest()) {
+						return testCase;
+					}
+				}
+			}
+		} catch (IndexOutOfBoundsException e) {
+			// don't care, children changed concurrently
+		}
+		return null;
+	}
 }

org.eclipse.jdt.junit/src/org/eclipse/jdt/internal/junit/ui/TestViewer.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2022 IBM Corporation and others.
+ * Copyright (c) 2000, 2023 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -448,10 +448,18 @@ private OpenTestAction getOpenTestAction(TestSuiteElement testSuite) {
 		String testName= testSuite.getTestName();
 		ITestElement[] children= testSuite.getChildren();
 
-		if (testName.startsWith("[") && testName.endsWith("]") && children.length > 0 && children[0] instanceof TestCaseElement) { //$NON-NLS-1$ //$NON-NLS-2$
+		if (children.length > 0 && children[0] instanceof TestCaseElement tce && tce.isDynamicTest()) {
 			// a group of parameterized tests
 			return new OpenTestAction(fTestRunnerPart, (TestCaseElement) children[0], null);
 		}
+		if (children.length == 0) {
+			// check if we have applied the workaround for: https://github.com/eclipse-jdt/eclipse.jdt.ui/issues/945
+			TestCaseElement child= testSuite.getSingleDynamicChild();
+			if (child != null) {
+				// a parameterized test that ran only one test
+				return new OpenTestAction(fTestRunnerPart, child, null);
+			}
+		}
 
 		int index= testName.indexOf('(');
 		// test factory method