[java] TestClassWithoutTestCases - improve message

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/errorprone/TestClassWithoutTestCasesRule.java

@@ -45,12 +45,20 @@ public class TestClassWithoutTestCasesRule extends AbstractJavaRule {
                 }
             }
             if (testMethods == 0 && nestedTestClasses == 0) {
-                addViolation(data, node);
+                addViolation(data, node, getSimpleClassName(node));
             }
         }
         return data;
     }
 
+    private String getSimpleClassName(ASTClassOrInterfaceBody node) {
+        JavaNode parent = node.getParent();
+        if (parent instanceof ASTClassOrInterfaceDeclaration) {
+            return ((ASTClassOrInterfaceDeclaration) parent).getSimpleName();
+        }
+        return "<anon>";
+    }
+
     private boolean isTestClassByPattern(ASTClassOrInterfaceBody node) {
         Pattern testClassPattern = getProperty(TEST_CLASS_PATTERN);
         if (testClassPattern.pattern().isEmpty()) {

pmd-java/src/main/resources/category/java/errorprone.xml

@@ -3332,13 +3332,13 @@ public void foo() {
     <rule name="TestClassWithoutTestCases"
           language="java"
           since="3.0"
-          message="This class name ends with 'Test' but contains no test cases"
+          message="The class ''{0}'' might be a test class, but it contains no test cases."
           class="net.sourceforge.pmd.lang.java.rule.errorprone.TestClassWithoutTestCasesRule"
           externalInfoUrl="${pmd.website.baseurl}/pmd_rules_java_errorprone.html#testclasswithouttestcases">
         <description>
-Test classes end with the suffix "Test" or "TestCase". Having a non-test class with that name is not a good practice,
-since most people will assume it is a test case. Test classes have test methods named "testXXX" (JUnit3) or use
-annotations (e.g. `@Test`).
+Test classes typically end with the suffix "Test", "Tests" or "TestCase". Having a non-test class with that name
+is not a good practice, since most people will assume it is a test case. Test classes have test methods
+named "testXXX" (JUnit3) or use annotations (e.g. `@Test`).
 
 The suffix can be configured using the property `testClassPattern`. To disable the detection of possible test classes
 by name, set this property to an empty string.

pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/errorprone/xml/TestClassWithoutTestCases.xml

@@ -7,6 +7,10 @@
     <test-code>
         <description>JUnit3: failure case</description>
         <expected-problems>1</expected-problems>
+        <expected-linenumbers>2</expected-linenumbers>
+        <expected-messages>
+            <message>The class 'FooTest' might be a test class, but it contains no test cases.</message>
+        </expected-messages>
         <code><![CDATA[
 import junit.framework.TestCase;
 public class FooTest extends TestCase {
@@ -234,6 +238,10 @@ class MyEmptyCase { }
         <rule-property name="testClassPattern">my\.pkg\..*Case$</rule-property>
         <expected-problems>2</expected-problems>
         <expected-linenumbers>2,3</expected-linenumbers>
+        <expected-messages>
+            <message>The class 'MyEmptyCase' might be a test class, but it contains no test cases.</message>
+            <message>The class 'MyNestedCase' might be a test class, but it contains no test cases.</message>
+        </expected-messages>
         <code><![CDATA[
 package my.pkg;
 class MyEmptyCase {