PoC: Add rewrite support for errorprone.refasterrules

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ concurrency:
   cancel-in-progress: true
 jobs:
   sanityCheck:
-    name: spotlessCheck assemble testClasses
+    name: QA (spotlessCheck, assemble testClasses, rewriteDryRun)
     runs-on: ubuntu-latest
     env:
       buildcacheuser: ${{ secrets.BUILDCACHE_USER }}
@@ -33,6 +33,8 @@ jobs:
         run: ./gradlew spotlessCheck
       - name: assemble testClasses
         run: ./gradlew assemble testClasses
+      - name: rewriteDryRun
+        run: ./gradlew rewriteDryRun --build-cache --info
   build:
     needs: sanityCheck
     strategy:
@@ -66,10 +68,10 @@ jobs:
         uses: gradle/actions/setup-gradle@v4
       - name: build (maven-only)
         if: matrix.kind == 'maven'
-        run: ./gradlew :plugin-maven:build -x spotlessCheck
+        run: ./gradlew :plugin-maven:build -x spotlessCheck -x rewriteDryRun
       - name: build (everything-but-maven)
         if: matrix.kind == 'gradle'
-        run: ./gradlew build -x spotlessCheck -PSPOTLESS_EXCLUDE_MAVEN=true
+        run: ./gradlew build -x spotlessCheck -x rewriteDryRun -PSPOTLESS_EXCLUDE_MAVEN=true
       - name: test npm
         if: matrix.kind == 'npm'
         run: ./gradlew testNpm

CHANGES.md

@@ -16,6 +16,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
   * Adds support for worktrees (fixes [#1765](https://github.com/diffplug/spotless/issues/1765))
 * Bump default `google-java-format` version to latest `1.24.0` -> `1.28.0`. ([#2345](https://github.com/diffplug/spotless/pull/2345))
 * Bump default `ktlint` version to latest `1.5.0` -> `1.7.1`. ([#2555](https://github.com/diffplug/spotless/pull/2555))
+* PoC: Add `rewrite` support for `errorprone.refasterrules` ([#2576](https://github.com/diffplug/spotless/pull/2576))
 
 ## [3.3.1] - 2025-07-21
 ### Fixed

build.gradle

@@ -1,29 +1,23 @@
 apply plugin: 'dev.equo.ide'
-equoIde {
-	branding().title('Spotless').icon(file('_images/spotless_logo.png'))
-	welcome().openUrl('https://github.com/diffplug/spotless/blob/main/CONTRIBUTING.md')
-	gradleBuildship().autoImport('.')
-}
 
-repositories {
-	mavenCentral()
-}
-
-apply from: rootProject.file('gradle/java-publish.gradle')
 apply from: rootProject.file('gradle/changelog.gradle')
+apply from: rootProject.file('gradle/java-publish.gradle')
+apply from: rootProject.file('gradle/spotless-freshmark.gradle')
+
 allprojects {
 	apply from: rootProject.file('gradle/spotless.gradle')
+	apply from: rootProject.file('gradle/rewrite.gradle')
+}
+
+equoIde {
+	branding().title('Spotless').icon(file('_images/spotless_logo.png'))
+	welcome().openUrl('https://github.com/diffplug/spotless/blob/main/CONTRIBUTING.md')
+	gradleBuildship().autoImport('.')
 }
-apply from: rootProject.file('gradle/spotless-freshmark.gradle')
 
-spotless {
-	groovyGradle {
-		target '*.gradle', 'gradle/*.gradle'
-	}
-	format 'dotfiles', {
-		target '.gitignore', '.gitattributes', '.editorconfig'
-		leadingTabsToSpaces(2)
-		trimTrailingWhitespace()
-		endWithNewline()
-	}
+dependencies {
+	rewrite("org.openrewrite.recipe:rewrite-migrate-java:3.14.1")
+	rewrite("org.openrewrite.recipe:rewrite-rewrite:0.10.1")
+	rewrite("org.openrewrite.recipe:rewrite-static-analysis:2.14.0")
+	rewrite("org.openrewrite.recipe:rewrite-third-party:0.24.1")
 }

gradle/rewrite.gradle

@@ -0,0 +1,49 @@
+apply plugin: 'org.openrewrite.rewrite'
+
+rewrite {
+	activeRecipe(
+			"org.openrewrite.gradle.GradleBestPractices",
+			"org.openrewrite.java.RemoveUnusedImports",
+			"org.openrewrite.java.format.RemoveTrailingWhitespace",
+			"org.openrewrite.java.recipes.JavaRecipeBestPractices",
+			"org.openrewrite.java.recipes.RecipeTestingBestPractices",
+			"org.openrewrite.staticanalysis.EmptyBlock",
+			"org.openrewrite.staticanalysis.EqualsAvoidsNull",
+			"org.openrewrite.staticanalysis.JavaApiBestPractices",
+			"org.openrewrite.staticanalysis.LowercasePackage",
+			"org.openrewrite.staticanalysis.MissingOverrideAnnotation",
+			"org.openrewrite.staticanalysis.ModifierOrder",
+			"org.openrewrite.staticanalysis.NoFinalizer",
+			"org.openrewrite.staticanalysis.RemoveCallsToSystemGc",
+			"org.openrewrite.staticanalysis.RemoveUnneededAssertion",
+			"org.openrewrite.staticanalysis.RemoveUnusedLocalVariables",
+			"org.openrewrite.staticanalysis.RemoveUnusedPrivateFields",
+			"org.openrewrite.staticanalysis.RemoveUnusedPrivateMethods",
+			"org.openrewrite.staticanalysis.StringLiteralEquality",
+			"org.openrewrite.staticanalysis.UnnecessaryParentheses",
+			"org.openrewrite.text.EndOfLineAtEndOfFile",
+			"tech.picnic.errorprone.refasterrules.BugCheckerRulesRecipes",
+			"tech.picnic.errorprone.refasterrules.CollectionRulesRecipes",
+			"tech.picnic.errorprone.refasterrules.FileRulesRecipes",
+			"tech.picnic.errorprone.refasterrules.NullRulesRecipes",
+			"tech.picnic.errorprone.refasterrules.StreamRulesRecipes",
+			"tech.picnic.errorprone.refasterrules.StringRulesRecipes",
+			"tech.picnic.errorprone.refasterrules.SuggestedFixRulesRecipes",
+			//"org.openrewrite.java.migrate.UpgradeToJava17",
+			//"org.openrewrite.staticanalysis.CodeCleanup",
+			//"org.openrewrite.staticanalysis.UnnecessaryThrows",
+			)
+	// bugs
+	exclusions.add("**AJacksonFormatterFunc.java")
+	exclusions.add("**NpmPathResolver.java")
+	exclusions.add("**NpmTestsWithoutNpmInstallationTest_gradle_node_plugin_example_*.gradle")
+	exclusions.add("**gradle/changelog.gradle")
+	exclusions.add("**gradle/java-publish.gradle")
+	exclusions.add("**lib-extra/build.gradle")
+	exclusions.add("**lib/build.gradle")
+	exclusions.add("**package-info.java")
+	exclusions.add("**plugin-maven/build.gradle")
+	exclusions.add("**settings.gradle")
+	exportDatatables = true
+	failOnDryRunResults = true
+}

gradle/spotless.gradle

@@ -1,33 +1,38 @@
 apply plugin: 'com.diffplug.spotless'
+
 spotless {
+	groovyGradle {
+		target '*.gradle', 'gradle/*.gradle'
+		greclipse().configFile rootProject.files('gradle/spotless.eclipseformat.xml', 'gradle/spotless.groovyformat.prefs')
+	}
+	format 'dotfiles', {
+		target '.gitignore', '.gitattributes', '.editorconfig'
+		leadingTabsToSpaces(2)
+		trimTrailingWhitespace()
+		endWithNewline()
+	}
 	def noInternalDepsClosure = {
 		String text = it
 		/*
 		 * No good way to get around using this import:
 		 * https://github.com/gradle/gradle/issues/3191
 		 */
 		String regex = "import org\\.gradle\\.api\\.internal\\.(?!plugins\\.DslObject)(?!project\\.ProjectInternal)"
-		if ((text.contains('import org.gradle.internal.') || text.find(regex)) &&
-				!text.contains('def noInternalDepsClosure')) {
+		if ((text.contains('import org.gradle.internal.') || text.find(regex))
+				&& !text.contains('def noInternalDepsClosure')) {
 			throw new AssertionError("Accidental internal import")
 		}
 	}
-	if (project != rootProject) {
-		// the rootProject doesn't have any java
-		java {
-			ratchetFrom 'origin/main'
-			bumpThisNumberIfACustomStepChanges(1)
-			licenseHeaderFile rootProject.file('gradle/spotless.license')
-			importOrderFile   rootProject.file('gradle/spotless.importorder')
-			eclipse().configFile rootProject.file('gradle/spotless.eclipseformat.xml')
-			trimTrailingWhitespace()
-			removeUnusedImports()
-			formatAnnotations()
-			custom 'noInternalDeps', noInternalDepsClosure
-		}
-	}
-	groovyGradle {
-		target '*.gradle'
-		greclipse().configFile rootProject.files('gradle/spotless.eclipseformat.xml', 'gradle/spotless.groovyformat.prefs')
+	java {
+		target '*.gitignore'
+		ratchetFrom 'origin/main'
+		bumpThisNumberIfACustomStepChanges(1)
+		licenseHeaderFile rootProject.file('gradle/spotless.license')
+		importOrderFile   rootProject.file('gradle/spotless.importorder')
+		eclipse().configFile rootProject.file('gradle/spotless.eclipseformat.xml')
+		trimTrailingWhitespace()
+		removeUnusedImports()
+		formatAnnotations()
+		custom 'noInternalDeps', noInternalDepsClosure
 	}
 }

lib-extra/src/jdt/java/com/diffplug/spotless/extra/glue/jdt/DefaultJavaElementComparator.java

@@ -368,8 +368,8 @@ private boolean isSortPreserved(BodyDeclaration bodyDeclaration) {
 	}
 
 	private int preserveRelativeOrder(BodyDeclaration bodyDeclaration1, BodyDeclaration bodyDeclaration2) {
-		int value1 = ((Integer) bodyDeclaration1.getProperty(CompilationUnitSorter.RELATIVE_ORDER));
-		int value2 = ((Integer) bodyDeclaration2.getProperty(CompilationUnitSorter.RELATIVE_ORDER));
+		int value1 = (Integer) bodyDeclaration1.getProperty(CompilationUnitSorter.RELATIVE_ORDER);
+		int value2 = (Integer) bodyDeclaration2.getProperty(CompilationUnitSorter.RELATIVE_ORDER);
 		return value1 - value2;
 	}
 

lib-extra/src/jdt/java/com/diffplug/spotless/extra/glue/jdt/JdtFlags.java

@@ -48,7 +48,7 @@ && isInterfaceOrAnnotationMember(bodyDeclaration))
 	}
 
 	private static boolean isPackageVisible(BodyDeclaration bodyDeclaration) {
-		return (!isPrivate(bodyDeclaration) && !isProtected(bodyDeclaration) && !isPublic(bodyDeclaration));
+		return !isPrivate(bodyDeclaration) && !isProtected(bodyDeclaration) && !isPublic(bodyDeclaration);
 	}
 
 	private static boolean isPrivate(BodyDeclaration bodyDeclaration) {

lib-extra/src/main/java/com/diffplug/spotless/extra/EquoBasedStepBuilder.java

@@ -20,12 +20,7 @@
 import java.io.File;
 import java.io.IOException;
 import java.io.Serializable;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.List;
-import java.util.Map;
-import java.util.Optional;
-import java.util.Properties;
+import java.util.*;
 
 import javax.annotation.Nullable;
 
@@ -127,7 +122,7 @@ public FormatterStep build() {
 		var roundtrippableState = new EquoStep(formatterVersion, settingProperties, settingXml, FileSignature.promise(settingsFiles), JarState.promise(() -> {
 			P2QueryResult query;
 			try {
-				if (null != cacheDirectory) {
+				if (cacheDirectory != null) {
 					CacheLocations.override_p2data = cacheDirectory.toPath().resolve("dev/equo/p2-data").toFile();
 				}
 				query = createModelWithMirrors().query(P2ClientCache.PREFER_OFFLINE, P2QueryCache.ALLOW);
@@ -190,8 +185,8 @@ static class EquoStep implements Serializable {
 				ImmutableMap<String, String> stepProperties) {
 
 			this.semanticVersion = semanticVersion;
-			this.settingProperties = Optional.ofNullable(settingProperties).orElse(new ArrayList<>());
-			this.settingXml = Optional.ofNullable(settingXml).orElse(new ArrayList<>());
+			this.settingProperties = Objects.requireNonNullElse(settingProperties, new ArrayList<>());
+			this.settingXml = Objects.requireNonNullElse(settingXml, new ArrayList<>());
 			this.settingsPromise = settingsPromise;
 			this.jarPromise = jarPromise;
 			this.stepProperties = stepProperties;
@@ -218,8 +213,8 @@ public static class State implements Serializable {
 		public State(String semanticVersion, JarState jarState, List<String> settingProperties, List<String> settingXml, FileSignature settingsFiles, ImmutableMap<String, String> stepProperties) {
 			this.semanticVersion = semanticVersion;
 			this.jarState = jarState;
-			this.settingProperties = Optional.ofNullable(settingProperties).orElse(new ArrayList<>());
-			this.settingXml = Optional.ofNullable(settingXml).orElse(new ArrayList<>());
+			this.settingProperties = Objects.requireNonNullElse(settingProperties, new ArrayList<>());
+			this.settingXml = Objects.requireNonNullElse(settingXml, new ArrayList<>());
 			this.settingsFiles = settingsFiles;
 			this.stepProperties = stepProperties;
 		}

lib-extra/src/main/java/com/diffplug/spotless/extra/GitAttributesLineEndings.java

@@ -146,15 +146,15 @@ static class CachedEndings implements Serializable {
 		private static final long serialVersionUID = -2534772773057900619L;
 
 		/** this is transient, to simulate PathSensitive.RELATIVE */
-		transient final String rootDir;
+		final transient String rootDir;
 		/** the line ending used for most files */
 		final String defaultEnding;
 		/** any exceptions to that default, in terms of relative path from rootDir */
 		final ConcurrentRadixTree<String> hasNonDefaultEnding = new ConcurrentRadixTree<>(new DefaultCharSequenceNodeFactory());
 
 		CachedEndings(File projectDir, Runtime runtime, Iterable<File> toFormat) {
 			String rootPath = FileSignature.pathNativeToUnix(projectDir.getAbsolutePath());
-			rootDir = rootPath.equals("/") ? rootPath : rootPath + "/";
+			rootDir = "/".equals(rootPath) ? rootPath : rootPath + "/";
 			defaultEnding = runtime.defaultEnding;
 			for (File file : toFormat) {
 				String ending = runtime.getEndingFor(file);

lib-extra/src/main/java/com/diffplug/spotless/extra/GitRatchet.java

@@ -132,9 +132,9 @@ private static boolean worktreeIsCleanCheckout(TreeWalk treeWalk) {
 		return treeWalk.idEqual(TREE, WORKDIR);
 	}
 
-	private final static int TREE = 0;
-	private final static int INDEX = 1;
-	private final static int WORKDIR = 2;
+	private static final int TREE = 0;
+	private static final int INDEX = 1;
+	private static final int WORKDIR = 2;
 
 	Map<File, Repository> gitRoots = new HashMap<>();
 	Table<Repository, String, ObjectId> rootTreeShaCache = HashBasedTable.create();

lib-extra/src/main/java/com/diffplug/spotless/extra/cpp/EclipseCdtFormatterStep.java

@@ -69,8 +69,8 @@ private static FormatterFunc apply(EquoBasedStepBuilder.State state) throws Exce
 						return (String) method.invoke(formatter, input);
 					} catch (InvocationTargetException exceptionWrapper) {
 						Throwable throwable = exceptionWrapper.getTargetException();
-						Exception exception = (throwable instanceof Exception) ? (Exception) throwable : null;
-						throw (null == exception) ? exceptionWrapper : exception;
+						Exception exception = throwable instanceof Exception ? (Exception) throwable : null;
+						throw exception == null ? exceptionWrapper : exception;
 					}
 				});
 	}

lib-extra/src/main/java/com/diffplug/spotless/extra/groovy/GrEclipseFormatterStep.java

@@ -97,8 +97,8 @@ private static FormatterFunc apply(EquoBasedStepBuilder.State state) throws Exce
 						return (String) method.invoke(formatter, input);
 					} catch (InvocationTargetException exceptionWrapper) {
 						Throwable throwable = exceptionWrapper.getTargetException();
-						Exception exception = (throwable instanceof Exception) ? (Exception) throwable : null;
-						throw (null == exception) ? exceptionWrapper : exception;
+						Exception exception = throwable instanceof Exception ? (Exception) throwable : null;
+						throw exception == null ? exceptionWrapper : exception;
 					}
 				});
 	}

lib-extra/src/main/java/com/diffplug/spotless/extra/integration/DiffMessageFormatter.java

@@ -251,7 +251,7 @@ public static Map.Entry<Integer, String> diff(Path rootDir, Formatter formatter,
 	}
 
 	private static Map.Entry<Integer, String> diff(CleanProvider formatter, File file) throws IOException {
-		String raw = new String(Files.readAllBytes(file.toPath()), formatter.getEncoding());
+		String raw = Files.readString(file.toPath(), formatter.getEncoding());
 		String rawUnix = LineEnding.toUnix(raw);
 		String formatted = formatter.getFormatted(file, rawUnix);
 		String formattedUnix = LineEnding.toUnix(formatted);

lib-extra/src/main/java/com/diffplug/spotless/extra/wtp/EclipseWtpFormatterStep.java

@@ -67,8 +67,8 @@ private static FormatterFunc applyWithoutFile(String className, EclipseBasedStep
 				return (String) method.invoke(formatter, input);
 			} catch (InvocationTargetException exceptionWrapper) {
 				Throwable throwable = exceptionWrapper.getTargetException();
-				Exception exception = (throwable instanceof Exception) ? (Exception) throwable : null;
-				throw (null == exception) ? exceptionWrapper : exception;
+				Exception exception = throwable instanceof Exception ? (Exception) throwable : null;
+				throw exception == null ? exceptionWrapper : exception;
 			}
 		};
 	}
@@ -85,8 +85,8 @@ public String applyWithFile(String unix, File file) throws Exception {
 					return (String) method.invoke(formatter, unix, file.getAbsolutePath());
 				} catch (InvocationTargetException exceptionWrapper) {
 					Throwable throwable = exceptionWrapper.getTargetException();
-					Exception exception = (throwable instanceof Exception) ? (Exception) throwable : null;
-					throw (null == exception) ? exceptionWrapper : exception;
+					Exception exception = throwable instanceof Exception ? (Exception) throwable : null;
+					throw exception == null ? exceptionWrapper : exception;
 				}
 			}
 		});

lib-extra/src/test/java/com/diffplug/spotless/extra/groovy/GrEclipseFormatterStepTest.java

@@ -24,8 +24,8 @@
 import com.diffplug.spotless.extra.eclipse.EquoResourceHarness;
 
 public class GrEclipseFormatterStepTest extends EquoResourceHarness {
-	private final static String INPUT = "class F{ def m(){} }";
-	private final static String EXPECTED = "class F{\n\tdef m(){}\n}";
+	private static final String INPUT = "class F{ def m(){} }";
+	private static final String EXPECTED = "class F{\n\tdef m(){}\n}";
 
 	public GrEclipseFormatterStepTest() {
 		super(GrEclipseFormatterStep.createBuilder(TestProvisioner.mavenCentral()));

lib-extra/src/test/java/com/diffplug/spotless/extra/wtp/EclipseWtpFormatterStepTest.java

@@ -19,6 +19,7 @@
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
+import java.nio.file.Files;
 import java.util.Properties;
 import java.util.function.Consumer;
 import java.util.stream.Stream;
@@ -33,7 +34,7 @@
 import com.diffplug.spotless.extra.eclipse.EclipseResourceHarness;
 
 public class EclipseWtpFormatterStepTest {
-	private final static Jvm.Support<String> JVM_SUPPORT = Jvm.<String> support("Oldest Version").add(8, "4.8.0");
+	private static final Jvm.Support<String> JVM_SUPPORT = Jvm.<String> support("Oldest Version").add(8, "4.8.0");
 
 	private static class NestedTests extends EclipseResourceHarness {
 		private final String unformatted, formatted;
@@ -76,7 +77,7 @@ void multipleConfigurations() throws Exception {
 		private File createPropertyFile(Consumer<Properties> config) throws IOException {
 			Properties configProps = new Properties();
 			config.accept(configProps);
-			File tempFile = File.createTempFile("EclipseWtpFormatterStepTest-", ".properties");
+			File tempFile = Files.createTempFile("EclipseWtpFormatterStepTest-", ".properties").toFile();
 			OutputStream tempOut = new FileOutputStream(tempFile);
 			configProps.store(tempOut, "test properties");
 			tempOut.flush();

lib/src/jackson/java/com/diffplug/spotless/glue/json/JacksonJsonFormatterFunc.java

@@ -53,6 +53,7 @@ protected Class<?> inferType(String input) {
 	 * @return a {@link JsonFactory}. May be overridden to handle alternative formats.
 	 * @see <a href="https://github.com/FasterXML/jackson-dataformats-text">jackson-dataformats-text</a>
 	 */
+	@Override
 	protected JsonFactory makeJsonFactory() {
 		JsonFactory jsonFactory = new JsonFactoryBuilder().build();