Issue #12099: Add ArchUnit test to ensure fields are modules and util…

…s are immutable and modules are correctly annotated

config/pmd-test.xml

@@ -119,7 +119,9 @@
              from the test method.
            In XdocsPagesTest PMD does not find asserts in lambdas.
            All test classes which starts with XpathRegression have asserts inside parent's method.
-           In ArchUnitTest assertion calls are not required as they are called by the library -->
+           In ArchUnitTest assertion calls are not required as they are called by the library
+           In ImmutabilityTest assertion calls are not required as they are called
+           by the library -->
       <property name="violationSuppressXPath"
                value="//ClassOrInterfaceDeclaration[@SimpleName='AllChecksTest'
                      or @SimpleName='AstRegressionTest'
@@ -132,6 +134,8 @@
                        //MethodDeclaration[@Name='testAllCheckSectionJavaDocs']
                    | //ClassOrInterfaceDeclaration[starts-with(@SimpleName,'XpathRegression')]
                        //MethodDeclaration
+                   | //ClassOrInterfaceDeclaration[@SimpleName='ImmutabilityTest']
+                       //MethodDeclaration
                    | //ClassOrInterfaceDeclaration[@SimpleName='ArchUnitTest']
                        //MethodDeclaration"/>
     </properties>

src/main/java/com/puppycrawl/tools/checkstyle/meta/XmlMetaReader.java

@@ -22,8 +22,10 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 import java.util.regex.Pattern;
 
@@ -67,10 +69,11 @@ private XmlMetaReader() {
      *
      * @param thirdPartyPackages fully qualified third party package names(can be only a
      *                           hint, e.g. for SevNTU it can be com.github.sevntu / com.github)
-     * @return list of module details found in the classpath satisfying the above conditions
+     * @return map of module full qualified name to module details found in the classpath satisfying
+     *         the above conditions
      * @throws IllegalStateException if there was a problem reading the module metadata files
      */
-    public static List<ModuleDetails> readAllModulesIncludingThirdPartyIfAny(
+    public static Map<String, ModuleDetails> readAllModulesIncludingThirdPartyIfAny(
             String... thirdPartyPackages) {
         final Set<String> standardModuleFileNames = new Reflections(
                 "com.puppycrawl.tools.checkstyle.meta", Scanners.Resources)
@@ -83,7 +86,7 @@ public static List<ModuleDetails> readAllModulesIncludingThirdPartyIfAny(
             allMetadataSources.addAll(thirdPartyModuleFileNames);
         }
 
-        final List<ModuleDetails> result = new ArrayList<>(allMetadataSources.size());
+        final Map<String, ModuleDetails> result = new HashMap<>(allMetadataSources.size(), 1.0F);
         for (String fileName : allMetadataSources) {
             final ModuleType moduleType;
             if (fileName.endsWith("FileFilter.xml")) {
@@ -104,7 +107,7 @@ else if (fileName.endsWith("Filter.xml")) {
                 throw new IllegalStateException("Problem to read all modules including third "
                         + "party if any. Problem detected at file: " + fileName, ex);
             }
-            result.add(moduleDetails);
+            result.put(moduleDetails.getFullQualifiedName(), moduleDetails);
         }
 
         return result;