Issue checkstyle#6207: Added XPath regression test for ClassTypeParam…

…eterName

src/it/java/org/checkstyle/suppressionxpathfilter/XpathRegressionClassTypeParameterNameTest.java

@@ -0,0 +1,128 @@
+///////////////////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
+// Copyright (C) 2001-2024 the original author or authors.
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+///////////////////////////////////////////////////////////////////////////////////////////////
+
+package org.checkstyle.suppressionxpathfilter;
+
+import java.io.File;
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import com.puppycrawl.tools.checkstyle.DefaultConfiguration;
+import com.puppycrawl.tools.checkstyle.checks.naming.AbstractClassNameCheck;
+import com.puppycrawl.tools.checkstyle.checks.naming.ClassTypeParameterNameCheck;
+
+public class XpathRegressionClassTypeParameterNameTest extends AbstractXpathTestSupport {
+
+    private final String checkName = ClassTypeParameterNameCheck.class.getSimpleName();
+
+    @Override
+    protected String getCheckName() {
+        return checkName;
+    }
+
+    @Test
+    public void testClass() throws Exception {
+        final File fileToProcess =
+                new File(getPath("InputXpathClassTypeParameterNameClass.java"));
+        final String pattern = "^[A-Z]$";
+        final DefaultConfiguration moduleConfig =
+                createModuleConfig(ClassTypeParameterNameCheck.class);
+
+        final String[] expectedViolation = {
+            "5:20: " + getCheckMessage(ClassTypeParameterNameCheck.class,
+                        AbstractClassNameCheck.MSG_ILLEGAL_ABSTRACT_CLASS_NAME, "abc", pattern),
+        };
+
+        final List<String> expectedXpathQueries = Arrays.asList(
+                "/COMPILATION_UNIT/CLASS_DEF"
+                        + "[./IDENT[@text='InputXpathClassTypeParameterNameClass']]"
+                        + "/OBJBLOCK/CLASS_DEF[./IDENT[@text='MyClass2']]"
+                        + "/TYPE_PARAMETERS/TYPE_PARAMETER[./IDENT[@text='abc']]",
+                "/COMPILATION_UNIT/CLASS_DEF"
+                        + "[./IDENT[@text='InputXpathClassTypeParameterNameClass']]"
+                        + "/OBJBLOCK/CLASS_DEF[./IDENT[@text='MyClass2']]/TYPE_PARAMETERS"
+                        + "/TYPE_PARAMETER/IDENT[@text='abc']"
+        );
+
+        runVerifications(moduleConfig, fileToProcess, expectedViolation,
+                expectedXpathQueries);
+    }
+
+    @Test
+    public void testInterface() throws Exception {
+        final String pattern = "^[A-Z]{2,}$";
+        final File fileToProcess =
+                new File(getPath("InputXpathClassTypeParameterNameInterface.java"));
+
+        final DefaultConfiguration moduleConfig =
+                createModuleConfig(ClassTypeParameterNameCheck.class);
+        moduleConfig.addProperty("format", pattern);
+
+        final String[] expectedViolation = {
+            "9:20: " + getCheckMessage(ClassTypeParameterNameCheck.class,
+                        AbstractClassNameCheck.MSG_ILLEGAL_ABSTRACT_CLASS_NAME, "aBc", pattern),
+        };
+
+        final List<String> expectedXpathQueries = Arrays.asList(
+                "/COMPILATION_UNIT/INTERFACE_DEF"
+                        + "[./IDENT[@text='InputXpathClassTypeParameterNameInterface']]"
+                        + "/OBJBLOCK/CLASS_DEF[./IDENT[@text='MyClass2']]"
+                        + "/TYPE_PARAMETERS/TYPE_PARAMETER[./IDENT[@text='aBc']]",
+                "/COMPILATION_UNIT/INTERFACE_DEF"
+                        + "[./IDENT[@text='InputXpathClassTypeParameterNameInterface']]"
+                        + "/OBJBLOCK/CLASS_DEF[./IDENT[@text='MyClass2']]"
+                        + "/TYPE_PARAMETERS/TYPE_PARAMETER/IDENT[@text='aBc']"
+        );
+        runVerifications(moduleConfig, fileToProcess, expectedViolation,
+                expectedXpathQueries);
+    }
+
+    @Test
+    public void testMethod() throws Exception {
+        final String pattern = "(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)";
+        final File fileToProcess =
+                new File(getPath("InputXpathClassTypeParameterNameMethod.java"));
+
+        final DefaultConfiguration moduleConfig =
+                createModuleConfig(ClassTypeParameterNameCheck.class);
+        moduleConfig.addProperty("format", pattern);
+
+        final String[] expectedViolation = {
+            "12:24: " + getCheckMessage(ClassTypeParameterNameCheck.class,
+                        AbstractClassNameCheck.MSG_ILLEGAL_ABSTRACT_CLASS_NAME, "ABC", pattern),
+        };
+
+        final List<String> expectedXpathQueries = Arrays.asList(
+                "/COMPILATION_UNIT/CLASS_DEF"
+                        + "[./IDENT[@text='InputXpathClassTypeParameterNameMethod']]"
+                        + "/OBJBLOCK/METHOD_DEF[./IDENT[@text='myTest2']]/SLIST/CLASS_DEF"
+                        + "[./IDENT[@text='MyClass2']]/TYPE_PARAMETERS"
+                        + "/TYPE_PARAMETER[./IDENT[@text='ABC']]",
+                "/COMPILATION_UNIT/CLASS_DEF"
+                        + "[./IDENT[@text='InputXpathClassTypeParameterNameMethod']]"
+                        + "/OBJBLOCK/METHOD_DEF[./IDENT[@text='myTest2']]/SLIST/CLASS_DEF"
+                        + "[./IDENT[@text='MyClass2']]/TYPE_PARAMETERS"
+                        + "/TYPE_PARAMETER/IDENT[@text='ABC']"
+        );
+        runVerifications(moduleConfig, fileToProcess, expectedViolation,
+                expectedXpathQueries);
+    }
+}

src/it/resources/org/checkstyle/suppressionxpathfilter/classtypeparametername/InputXpathClassTypeParameterNameClass.java

@@ -0,0 +1,7 @@
+package org.checkstyle.suppressionxpathfilter.classtypeparametername;
+
+public class InputXpathClassTypeParameterNameClass {
+    class MyClass1<A> {}
+    class MyClass2<abc> {} // warn
+    class MyClass3<B> {}
+}

src/it/resources/org/checkstyle/suppressionxpathfilter/classtypeparametername/InputXpathClassTypeParameterNameInterface.java

@@ -0,0 +1,16 @@
+package org.checkstyle.suppressionxpathfilter.classtypeparametername;
+
+interface InputXpathClassTypeParameterNameInterface {
+
+    class MyClass1<LISTENER> {
+        public void myTest1() {}
+    }
+
+    class MyClass2<aBc> { // warn
+        public void myTest2() {}
+    }
+
+    class MyClass3<REQUESTA> {
+        public void myTest3() {}
+    }
+}

src/it/resources/org/checkstyle/suppressionxpathfilter/classtypeparametername/InputXpathClassTypeParameterNameMethod.java

@@ -0,0 +1,22 @@
+package org.checkstyle.suppressionxpathfilter.classtypeparametername;
+
+public class InputXpathClassTypeParameterNameMethod {
+
+    public void myTest1() {
+        class MyClass1<T> {
+            public void test() {}
+        }
+    }
+
+    public void myTest2() {
+        class MyClass2<ABC> { // warn
+            public void test() {}
+        }
+    }
+
+    public void myTest3() {
+    class MyClass3<RequestT> {
+        public void test() {}
+    }
+}
+}

src/test/java/com/puppycrawl/tools/checkstyle/internal/XpathRegressionTest.java

@@ -92,7 +92,6 @@ public class XpathRegressionTest extends AbstractModuleTestSupport {
     // till https://github.com/checkstyle/checkstyle/issues/6207
     private static final Set<String> MISSING_CHECK_NAMES = Set.of(
             "ClassFanOutComplexity",
-            "ClassTypeParameterName",
             "DescendantToken",
             "DesignForExtension",
             "HideUtilityClassConstructor",