Issue #41: Added AbstractRecipeTestSupport

config/suppressions.xml

@@ -9,5 +9,6 @@
     <suppress checks="JavadocVariable" files=".*"/>
     <suppress checks="MissingJavadocMethod" files=".*"/>
     <suppress checks="DesignForExtension" files="[\\/]src[\\/]test[\\/]java[\\/]org[\\/]checkstyle[\\/]autofix[\\/]recipe[\\/]AbstractRecipeTest\.java"/>
+    <suppress checks="DesignForExtension" files="[\\/]src[\\/]test[\\/]java[\\/]org[\\/]checkstyle[\\/]autofix[\\/]recipe[\\/]AbstractRecipeTestSupport\.java"/>
     <suppress checks="DesignForExtension" files="[\\/]src[\\/]main[\\/]java[\\/]org[\\/]checkstyle[\\/]autofix[\\/]CheckstyleAutoFix\.java"/>
 </suppressions>

pom.xml

@@ -65,6 +65,13 @@
         </dependency>
 
         <!-- Test dependencies -->
+        <dependency>
+            <groupId>com.puppycrawl.tools</groupId>
+            <artifactId>checkstyle</artifactId>
+            <version>${checkstyle.version}</version>
+            <classifier>tests</classifier>
+            <scope>test</scope>
+        </dependency>
         <dependency>
             <groupId>org.openrewrite</groupId>
             <artifactId>rewrite-test</artifactId>

src/test/java/org/checkstyle/autofix/recipe/AbstractRecipeTestSupport.java

@@ -0,0 +1,116 @@
+///////////////////////////////////////////////////////////////////////////////////////////////
+// checkstyle-openrewrite-recipes: Automatically fix Checkstyle violations with OpenRewrite.
+// Copyright (C) 2025 The Checkstyle OpenRewrite Recipes Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+///////////////////////////////////////////////////////////////////////////////////////////////
+
+package org.checkstyle.autofix.recipe;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.openrewrite.java.Assertions.java;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Collections;
+import java.util.List;
+
+import org.checkstyle.autofix.InputClassRenamer;
+import org.checkstyle.autofix.parser.CheckstyleReportParser;
+import org.checkstyle.autofix.parser.CheckstyleViolation;
+import org.openrewrite.Recipe;
+import org.openrewrite.test.RewriteTest;
+
+import com.puppycrawl.tools.checkstyle.AbstractXmlTestSupport;
+import com.puppycrawl.tools.checkstyle.Checker;
+import com.puppycrawl.tools.checkstyle.XMLLogger;
+import com.puppycrawl.tools.checkstyle.api.Configuration;
+import com.puppycrawl.tools.checkstyle.bdd.InlineConfigParser;
+import com.puppycrawl.tools.checkstyle.bdd.TestInputConfiguration;
+
+public abstract class AbstractRecipeTestSupport extends AbstractXmlTestSupport
+        implements RewriteTest {
+
+    protected abstract String getSubpackage();
+
+    protected abstract String getCheckName();
+
+    protected abstract Recipe createRecipe(List<CheckstyleViolation> violations);
+
+    @Override
+    protected String getPackageLocation() {
+        return "org/checkstyle/autofix/recipe/" + getSubpackage();
+    }
+
+    private Recipe createPreprocessingRecipe() {
+        return new InputClassRenamer();
+    }
+
+    protected void verify(String testCaseName) throws Exception {
+        final String inputFileName = "Input" + testCaseName + ".java";
+        final String outputFileName = "Output" + testCaseName + ".java";
+        final String inputPath = testCaseName.toLowerCase() + "/" + inputFileName;
+        final String outputPath = testCaseName.toLowerCase() + "/" + outputFileName;
+
+        final Configuration config = getCheckConfigurations(inputPath);
+        final List<CheckstyleViolation> violations = runCheckstyle(inputPath, config);
+
+        final String beforeCode = readFile(getPath(inputPath));
+        final String expectedAfterCode = readFile(getPath(outputPath));
+
+        final Recipe mainRecipe = createRecipe(violations);
+
+        testRecipe(beforeCode, expectedAfterCode,
+                getPath(inputPath), createPreprocessingRecipe(), mainRecipe);
+    }
+
+    private List<CheckstyleViolation> runCheckstyle(String inputPath,
+                                                    Configuration config) throws Exception {
+
+        final Checker checker = createChecker(config);
+        final ByteArrayOutputStream xmlOutput = new ByteArrayOutputStream();
+        final XMLLogger logger = new XMLLogger(xmlOutput, XMLLogger.OutputStreamOptions.CLOSE);
+        checker.addListener(logger);
+
+        final List<File> filesToCheck = Collections.singletonList(new File(getPath(inputPath)));
+        checker.process(filesToCheck);
+
+        final Path tempXmlPath = Files.createTempFile("checkstyle-report", ".xml");
+        try {
+            Files.write(tempXmlPath, xmlOutput.toByteArray());
+            return CheckstyleReportParser.parse(tempXmlPath);
+        }
+        finally {
+            Files.deleteIfExists(tempXmlPath);
+        }
+    }
+
+    private Configuration getCheckConfigurations(String inputPath) throws Exception {
+        final String configFilePath = getPath(inputPath);
+        final TestInputConfiguration testInputConfiguration =
+                InlineConfigParser.parse(configFilePath);
+        return testInputConfiguration.createConfiguration();
+    }
+
+    private void testRecipe(String beforeCode, String expectedAfterCode,
+                            String filePath, Recipe... recipes) {
+        assertDoesNotThrow(() -> {
+            rewriteRun(
+                    spec -> spec.recipes(recipes),
+                    java(beforeCode, expectedAfterCode, spec -> spec.path(filePath))
+            );
+        });
+    }
+}