Issue #12099: Add ArchUnit test to detect cycles in packages

.ci/jsoref-spellchecker/exclude.pl

@@ -18,6 +18,7 @@
   ^cdg-pitest-licence.txt$
   ^.teamcity/
   ^.ci/checker-framework-suppressions/
+  ^config/archunit-store/
 );
 my $exclude = join "|", @excludes;
 while (<>) {

config/archunit-store/stored.rules

@@ -0,0 +1 @@
+slices\ matching\ 'com.puppycrawl.tools.checkstyle.(**)'\ should\ be\ free\ of\ cycles=slices_should_be_free_of_cycles_suppressions

config/checkstyle_non_main_files_suppressions.xml

@@ -47,6 +47,11 @@
   <suppress checks="NewlineAtEndOfFile"
              files="[\\/]test[\\/].*[\\/]checks[\\/]uniqueproperties[\\/]InputUniquePropertiesWithDuplicates\.properties"/>
 
+  <!-- ArchUnit store is automatically updated by ArchUnit which
+       does not add new line at the end. -->
+  <suppress checks="NewlineAtEndOfFile"
+            files="config[\\/]archunit-store[\\/]slices_should_be_free_of_cycles_suppressions"/>
+
   <!-- till https://issues.apache.org/jira/browse/MRELEASE-1008 -->
   <suppress id="lineLength" files="pom.xml"/>
   <!-- this file cannot be line wraped -->
@@ -98,6 +103,9 @@
   <!-- this file cannot be line wrapped, it contains cdg pitest licence -->
   <suppress id="lineLength" files="cdg-pitest-licence.txt"/>
 
+  <!-- files in this directory cannot be line wrapped as they are generated by ArchUnit -->
+  <suppress id="lineLength" files="config[\\/]archunit-store.*"/>
+
   <!-- apply check numberOfTestCasesInXpath only for files in suppressionxpathfilter directory -->
   <suppress id="numberOfTestCasesInXpath"
          files="src[\\/]it[\\/]java[\\/]com[\\/].*" />

config/pmd-test.xml

@@ -119,8 +119,8 @@
              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, ArchUnitSuperClassTest, ImmutabilityTest assertion calls are not
-           required as they are called by the library -->
+           In ArchUnitTest, ArchUnitSuperClassTest, ImmutabilityTest, ArchUnitCyclesCheckTest
+           assertion calls are not required as they are called by the library -->
       <property name="violationSuppressXPath"
                value="//ClassOrInterfaceDeclaration[@SimpleName='AllChecksTest'
                      or @SimpleName='AstRegressionTest'
@@ -138,6 +138,8 @@
                    | //ClassOrInterfaceDeclaration[@SimpleName='ArchUnitTest']
                        //MethodDeclaration
                    | //ClassOrInterfaceDeclaration[@SimpleName='ArchUnitSuperClassTest']
+                       //MethodDeclaration
+                   | //ClassOrInterfaceDeclaration[@SimpleName='ArchUnitCyclesCheckTest']
                        //MethodDeclaration"/>
     </properties>
   </rule>

pom.xml

@@ -1641,6 +1641,7 @@
                 <exclude>markdownlint.rb</exclude>
                 <exclude>signatures.txt</exclude>
                 <exclude>signatures-test.txt</exclude>
+                <exclude>archunit-store/**</exclude>
               </excludes>
             </validationSet>
             <validationSet>

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

@@ -0,0 +1,63 @@
+///////////////////////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code and other text files for adherence to a set of rules.
+// Copyright (C) 2001-2022 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 com.puppycrawl.tools.checkstyle.internal;
+
+import static com.tngtech.archunit.library.dependencies.SlicesRuleDefinition.slices;
+
+import org.junit.jupiter.api.Test;
+
+import com.tngtech.archunit.core.domain.JavaClasses;
+import com.tngtech.archunit.core.importer.ClassFileImporter;
+import com.tngtech.archunit.core.importer.ImportOption;
+import com.tngtech.archunit.lang.ArchRule;
+import com.tngtech.archunit.library.freeze.FreezingArchRule;
+
+public class ArchUnitCyclesCheckTest {
+
+    /**
+     * This test checks that
+     * <a href="https://www.archunit.org/userguide/html/000_Index.html#_slices">slices</a> should
+     * be free of
+     * <a href="https://www.archunit.org/userguide/html/000_Index.html#_cycle_checks">cycles</a>.
+     * In this particular test, each slice is a different package. Currently the violations from
+     * this test are frozen using
+     * <a href="https://www.archunit.org/userguide/html/000_Index.html#_freezing_arch_rules">
+     * FreezingArchRule</a>.
+     *
+     * <p>Whenever a new cycle is introduced or removed, the test will pass successfully but the
+     * frozen violations will be updated. It is highly recommended to avoid new cycles and, it
+     * is preferred to remove them. In both cases commit the changes for further discussion.
+     *
+     * <p>The frozen violations are present in {@code config/archunit-store} directory.
+     */
+    @Test
+    public void testSlicesShouldBeFreeOfCycles() {
+        final JavaClasses importedClasses = new ClassFileImporter()
+            .withImportOption(ImportOption.Predefined.DO_NOT_INCLUDE_TESTS)
+            .importPackages("com.puppycrawl.tools.checkstyle");
+
+        final ArchRule slicesShouldBeFreeOfCycles = FreezingArchRule.freeze(
+            slices()
+            .matching("com.puppycrawl.tools.checkstyle.(**)")
+            .should().beFreeOfCycles());
+
+        slicesShouldBeFreeOfCycles.check(importedClasses);
+    }
+}

src/test/resources/archunit.properties

@@ -0,0 +1,17 @@
+# This will limit the maximum number of dependencies to report per cycle edge.
+# Note that ArchUnit will regardless always analyze all dependencies to detect cycles,
+# so this purely affects how many dependencies will be printed in the report.
+# Also note that this number will quickly affect the required heap since it scales with number.
+# of edges and number of cycles
+# default is 20
+cycles.maxNumberOfDependenciesPerEdge=550
+
+# This will limit the maximum number of cycles to detect and thus required CPU and heap.
+# default is 100
+cycles.maxNumberToDetect=200
+
+# The store will be updated with the current state, and the reported result will be success.
+# Just like freezing violation for the first time while creating the store.
+freeze.refreeze=true
+
+freeze.store.default.path=config/archunit-store