Introduce cleanthat refactorer

CHANGES.md

@@ -10,6 +10,8 @@ This document is intended for Spotless developers.
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Added
+* CleanThat Java Refactorer ([#???](https://github.com/diffplug/spotless/pull/???))
 
 ## [2.34.1] - 2023-02-05
 ### Changes

README.md

@@ -84,6 +84,7 @@ lib('java.PalantirJavaFormatStep')               +'{{yes}}       | {{yes}}
 lib('java.RemoveUnusedImportsStep')              +'{{yes}}       | {{yes}}      | {{yes}}      | {{no}}  |',
 extra('java.EclipseJdtFormatterStep')            +'{{yes}}       | {{yes}}      | {{yes}}      | {{no}}  |',
 lib('java.FormatAnnotationsStep')                +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
+lib('java.CleanthatJavaStep')                    +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
 lib('json.gson.GsonStep')                        +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
 lib('json.JacksonJsonStep')                      +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
 lib('json.JsonSimpleStep')                       +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
@@ -131,6 +132,7 @@ lib('yaml.JacksonYamlStep')                      +'{{yes}}       | {{yes}}
 | [`java.RemoveUnusedImportsStep`](lib/src/main/java/com/diffplug/spotless/java/RemoveUnusedImportsStep.java) | :+1:       | :+1:      | :+1:      | :white_large_square:  |
 | [`java.EclipseJdtFormatterStep`](lib-extra/src/main/java/com/diffplug/spotless/extra/java/EclipseJdtFormatterStep.java) | :+1:       | :+1:      | :+1:      | :white_large_square:  |
 | [`java.FormatAnnotationsStep`](lib/src/main/java/com/diffplug/spotless/java/FormatAnnotationsStep.java) | :+1:       | :+1:      | :white_large_square:       | :white_large_square:  |
+| [`java.CleanthatJavaStep`](lib/src/main/java/com/diffplug/spotless/java/CleanthatJavaStep.java) | :+1:       | :+1:      | :white_large_square:       | :white_large_square:  |
 | [`json.gson.GsonStep`](lib/src/main/java/com/diffplug/spotless/json/gson/GsonStep.java) | :+1:       | :+1:      | :white_large_square:       | :white_large_square:  |
 | [`json.JacksonJsonStep`](lib/src/main/java/com/diffplug/spotless/json/JacksonJsonStep.java) | :+1:       | :+1:      | :white_large_square:       | :white_large_square:  |
 | [`json.JsonSimpleStep`](lib/src/main/java/com/diffplug/spotless/json/JsonSimpleStep.java) | :+1:       | :+1:      | :white_large_square:       | :white_large_square:  |

lib/build.gradle

@@ -16,7 +16,8 @@ def NEEDS_GLUE = [
 	'diktat',
 	'scalafmt',
 	'jackson',
-	'gson'
+	'gson',
+	'cleanthat'
 ]
 for (glue in NEEDS_GLUE) {
 	sourceSets.register(glue) {
@@ -39,6 +40,12 @@ versionCompatibility {
 			]
 			targetSourceSetName = 'ktlint'
 		}
+		namespaces.register('Cleanthat') {
+			versions = [
+				'2.1',
+			]
+			targetSourceSetName = 'cleanthat'
+		}
 	}
 }
 
@@ -100,6 +107,9 @@ dependencies {
 	flexmarkCompileOnly 'com.vladsch.flexmark:flexmark-all:0.62.2'
 
 	gsonCompileOnly 'com.google.code.gson:gson:2.10.1'
+
+	cleanthatCompileOnly 'io.github.solven-eu.cleanthat:java:2.1'
+	compatCleanthat2Dot1CompileAndTestOnly 'io.github.solven-eu.cleanthat:java:2.1'
 }
 
 // we'll hold the core lib to a high standard

lib/src/cleanthat/java/com/diffplug/spotless/glue/java/JavaCleanthatRefactorerFunc.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2023 DiffPlug
+ *
+ * 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 com.diffplug.spotless.glue.java;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.diffplug.spotless.FormatterFunc;
+
+import eu.solven.cleanthat.config.pojo.CleanthatEngineProperties;
+import eu.solven.cleanthat.config.pojo.SourceCodeProperties;
+import eu.solven.cleanthat.engine.java.IJdkVersionConstants;
+import eu.solven.cleanthat.engine.java.refactorer.JavaRefactorer;
+import eu.solven.cleanthat.engine.java.refactorer.JavaRefactorerProperties;
+import eu.solven.cleanthat.formatter.LineEnding;
+
+/**
+ * The glue for CleanThat: it is build over the version in build.gradle, but at runtime it will be executed over
+ * the version loaded in JarState, which is by default defined in com.diffplug.spotless.java.CleanthatJavaStep#JVM_SUPPORT
+ */
+public class JavaCleanthatRefactorerFunc implements FormatterFunc {
+	private static final Logger LOGGER = LoggerFactory.getLogger(JavaCleanthatRefactorerFunc.class);
+
+	private String jdkVersion;
+	private List<String> included;
+	private List<String> excluded;
+
+	public JavaCleanthatRefactorerFunc(String jdkVersion, List<String> included, List<String> excluded) {
+		this.jdkVersion = jdkVersion == null ? IJdkVersionConstants.JDK_8 : jdkVersion;
+		this.included = included == null ? Collections.emptyList() : included;
+		this.excluded = excluded == null ? Collections.emptyList() : excluded;
+	}
+
+	public JavaCleanthatRefactorerFunc() {
+		this(IJdkVersionConstants.JDK_8, Arrays.asList(JavaRefactorerProperties.WILDCARD), Arrays.asList());
+	}
+
+	@Override
+	public String apply(String input) throws Exception {
+		// https://stackoverflow.com/questions/1771679/difference-between-threads-context-class-loader-and-normal-classloader
+		ClassLoader originalClassLoader = Thread.currentThread().getContextClassLoader();
+		try {
+			// Ensure CleanThat main Thread has its custom classLoader while executing its refactoring
+			Thread.currentThread().setContextClassLoader(getClass().getClassLoader());
+			return doApply(input);
+		} finally {
+			// Restore the originalClassLoader
+			Thread.currentThread().setContextClassLoader(originalClassLoader);
+		}
+	}
+
+	private String doApply(String input) throws InterruptedException, IOException {
+		// call some API that uses reflection without taking ClassLoader param
+		CleanthatEngineProperties engineProperties = CleanthatEngineProperties.builder().engineVersion(jdkVersion).build();
+
+		// Spotless will push us LF content
+		engineProperties.setSourceCode(SourceCodeProperties.builder().lineEnding(LineEnding.LF).build());
+
+		JavaRefactorerProperties refactorerProperties = new JavaRefactorerProperties();
+
+		refactorerProperties.setIncluded(included);
+		refactorerProperties.setExcluded(excluded);
+
+		JavaRefactorer refactorer = new JavaRefactorer(engineProperties, refactorerProperties);
+
+		LOGGER.debug("Processing sourceJdk={} included={} excluded={}", jdkVersion, included, excluded);
+		LOGGER.debug("Available mutators: {}", JavaRefactorer.getAllIncluded());
+
+		// Spotless calls steps always with LF eol.
+		return refactorer.doFormat(input, LineEnding.LF);
+	}
+
+}

lib/src/main/java/com/diffplug/spotless/java/CleanthatJavaStep.java

@@ -0,0 +1,159 @@
+/*
+ * Copyright 2023 DiffPlug
+ *
+ * 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 com.diffplug.spotless.java;
+
+import java.io.IOException;
+import java.io.Serializable;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
+import java.util.List;
+import java.util.Objects;
+
+import com.diffplug.spotless.FormatterFunc;
+import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.JarState;
+import com.diffplug.spotless.Jvm;
+import com.diffplug.spotless.Provisioner;
+
+/**
+ * Enables CleanThat as a SpotLess step.
+ *
+ * @author Benoit Lacelle
+ */
+// https://github.com/diffplug/spotless/blob/main/CONTRIBUTING.md#how-to-add-a-new-formatterstep
+public final class CleanthatJavaStep {
+
+	private static final String NAME = "cleanthat";
+	private static final String MAVEN_COORDINATE = "io.github.solven-eu.cleanthat:java";
+
+	// CleanThat changelog is available at https://github.com/solven-eu/cleanthat/blob/master/CHANGES.MD
+	private static final Jvm.Support<String> JVM_SUPPORT = Jvm.<String> support(NAME).add(11, "2.1");
+
+	// prevent direct instantiation
+	private CleanthatJavaStep() {}
+
+	/** Creates a step which apply default CleanThat mutators. */
+	public static FormatterStep create(Provisioner provisioner) {
+		return create(defaultVersion(), provisioner);
+	}
+
+	/** Creates a step which apply default CleanThat mutators. */
+	public static FormatterStep create(String version, Provisioner provisioner) {
+		return create(MAVEN_COORDINATE, version, defaultSourceJdk(), defaultExcludedMutators(), defaultMutators(), provisioner);
+	}
+
+	public static String defaultSourceJdk() {
+		// see IJdkVersionConstants.JDK_7
+		// https://maven.apache.org/plugins/maven-compiler-plugin/compile-mojo.html#source
+		// 1.7 is the default for 'maven-compiler-plugin' since 3.9.0
+		return "1.7";
+	}
+
+	public static List<String> defaultExcludedMutators() {
+		return List.of();
+	}
+
+	/**
+	 * By default, we include all available rules
+	 * @return
+	 */
+	public static List<String> defaultMutators() {
+		// see JavaRefactorerProperties.WILDCARD
+		return List.of("*");
+	}
+
+	/** Creates a step which apply selected CleanThat mutators. */
+	public static FormatterStep create(String groupArtifact,
+			String version,
+			String sourceJdkVersion,
+			List<String> excluded,
+			List<String> included,
+			Provisioner provisioner) {
+		Objects.requireNonNull(groupArtifact, "groupArtifact");
+		if (groupArtifact.chars().filter(ch -> ch == ':').count() != 1) {
+			throw new IllegalArgumentException("groupArtifact must be in the form 'groupId:artifactId'. it was: " + groupArtifact);
+		}
+		Objects.requireNonNull(version, "version");
+		Objects.requireNonNull(provisioner, "provisioner");
+		return FormatterStep.createLazy(NAME,
+				() -> new JavaRefactorerState(NAME, groupArtifact, version, sourceJdkVersion, excluded, included, provisioner),
+				JavaRefactorerState::createFormat);
+	}
+
+	/** Get default formatter version */
+	public static String defaultVersion() {
+		return JVM_SUPPORT.getRecommendedFormatterVersion();
+	}
+
+	public static String defaultGroupArtifact() {
+		return MAVEN_COORDINATE;
+	}
+
+	static final class JavaRefactorerState implements Serializable {
+		private static final long serialVersionUID = 1L;
+
+		final JarState jarState;
+		final String stepName;
+		final String version;
+
+		final String sourceJdkVersion;
+		final List<String> included;
+		final List<String> excluded;
+
+		JavaRefactorerState(String stepName, String version, Provisioner provisioner) throws IOException {
+			this(stepName, MAVEN_COORDINATE, version, defaultSourceJdk(), defaultExcludedMutators(), defaultMutators(), provisioner);
+		}
+
+		JavaRefactorerState(String stepName,
+				String groupArtifact,
+				String version,
+				String sourceJdkVersion,
+				List<String> included,
+				List<String> excluded,
+				Provisioner provisioner) throws IOException {
+			JVM_SUPPORT.assertFormatterSupported(version);
+			ModuleHelper.doOpenInternalPackagesIfRequired();
+			this.jarState = JarState.from(groupArtifact + ":" + version, provisioner);
+			this.stepName = stepName;
+			this.version = version;
+
+			this.sourceJdkVersion = sourceJdkVersion;
+			this.included = included;
+			this.excluded = excluded;
+		}
+
+		@SuppressWarnings("PMD.UseProperClassLoader")
+		FormatterFunc createFormat() {
+			ClassLoader classLoader = jarState.getClassLoader();
+
+			Object formatter;
+			Method formatterMethod;
+			try {
+				Class<?> formatterClazz = classLoader.loadClass("com.diffplug.spotless.glue.java.JavaCleanthatRefactorerFunc");
+				Constructor<?> formatterConstructor = formatterClazz.getConstructor(String.class, List.class, List.class);
+
+				formatter = formatterConstructor.newInstance(sourceJdkVersion, included, excluded);
+				formatterMethod = formatterClazz.getMethod("apply", String.class);
+			} catch (ReflectiveOperationException e) {
+				throw new IllegalStateException("Issue executing the formatter", e);
+			}
+			return JVM_SUPPORT.suggestLaterVersionOnError(version, input -> {
+				return (String) formatterMethod.invoke(formatter, input);
+			});
+		}
+
+	}
+}

lib/src/testCompatCleanthat2Dot1/java/com/diffplug/spotless/glue/java/JavaCleanthatRefactorerFuncTest.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2023 DiffPlug
+ *
+ * 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 com.diffplug.spotless.glue.java;
+
+import org.assertj.core.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import eu.solven.cleanthat.engine.java.refactorer.JavaRefactorer;
+
+public class JavaCleanthatRefactorerFuncTest {
+	@Test
+	public void testMutatorsDetection() {
+		Assertions.assertThat(JavaRefactorer.getAllIncluded()).isNotEmpty();
+	}
+}

plugin-gradle/CHANGES.md

@@ -3,6 +3,8 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `3.27.0`).
 
 ## [Unreleased]
+### Added
+* CleanThat Java Refactorer ([#1560](https://github.com/diffplug/spotless/pull/1560))
 
 ## [6.14.1] - 2023-02-05
 ### Fixed

plugin-gradle/README.md

@@ -54,7 +54,7 @@ Spotless supports all of Gradle's built-in performance features (incremental bui
 - [**Quickstart**](#quickstart)
   - [Requirements](#requirements)
 - **Languages**
-  - [Java](#java) ([google-java-format](#google-java-format), [eclipse jdt](#eclipse-jdt), [clang-format](#clang-format), [prettier](#prettier), [palantir-java-format](#palantir-java-format), [formatAnnotations](#formatAnnotations))
+  - [Java](#java) ([google-java-format](#google-java-format), [eclipse jdt](#eclipse-jdt), [clang-format](#clang-format), [prettier](#prettier), [palantir-java-format](#palantir-java-format), [formatAnnotations](#formatAnnotations), [cleanthat](#cleanthat))
   - [Groovy](#groovy) ([eclipse groovy](#eclipse-groovy))
   - [Kotlin](#kotlin) ([ktfmt](#ktfmt), [ktlint](#ktlint), [diktat](#diktat), [prettier](#prettier))
   - [Scala](#scala) ([scalafmt](#scalafmt))
@@ -154,6 +154,9 @@ spotless {
 
     removeUnusedImports()
 
+    // Cleanthat will refactor your code, but it may break your style: apply it before your formatter
+    cleanthat()          // has its own section below
+
     // Choose one of these formatters.
     googleJavaFormat()   // has its own section below
     eclipse()            // has its own section below
@@ -257,6 +260,23 @@ You can use `addTypeAnnotation()` and `removeTypeAnnotation()` to override its d
 
 You can make a pull request to add new annotations to Spotless's default list.
 
+### cleanthat
+
+[homepage](https://github.com/solven-eu/cleanthat). CleanThat enables automatic refactoring of Java code. [ChangeLog](https://github.com/solven-eu/cleanthat/blob/master/CHANGES.MD)
+
+```gradle
+spotless {
+  java {
+    cleanthat()
+    // optional: you can specify a specific version and/or config file
+    cleanthat()
+      .groupArtifact('1.7')                 // default is 'io.github.solven-eu.cleanthat:java'
+      .version('2.1')                             // You may force a past of -SNAPSHOT
+      .sourceCompatibility('1.7')                 // default is '1.7'
+      .addMutator('your.custom.MagicMutator')
+      .excludeMutator('UseCollectionIsEmpty')
+```
+
 
 <a name="applying-to-groovy-source"></a>