[Experimental] Add rewrite support for RemoveUnusedPrivateMethods & RemoveUnusedImports

Author: Vincent Potucek

build.gradle

@@ -1,20 +1,28 @@
 apply plugin: 'dev.equo.ide'
+apply plugin: 'org.openrewrite.rewrite'
+
+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')
+}
+
 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')
-allprojects {
-	apply from: rootProject.file('gradle/spotless.gradle')
+rewrite {
+	activeRecipe("org.openrewrite.gradle.GradleBestPractices")
+	activeRecipe("org.openrewrite.java.RemoveUnusedImports")
+	//activeRecipe("org.openrewrite.staticanalysis.RemoveUnusedLocalVariables") bug
+	activeRecipe("org.openrewrite.staticanalysis.RemoveUnusedPrivateFields")
+	activeRecipe("org.openrewrite.staticanalysis.RemoveUnusedPrivateMethods")
+	failOnDryRunResults = true
 }
-apply from: rootProject.file('gradle/spotless-freshmark.gradle')
 
 spotless {
 	groovyGradle {
@@ -27,3 +35,16 @@ spotless {
 		endWithNewline()
 	}
 }
+
+// off switch for release: ' -x check' or ' -x rewriteDryRun spotlessJavaCheck'
+tasks {
+	check.dependsOn(rewriteDryRun, spotlessCheck)
+}
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	rewrite("org.openrewrite.recipe:rewrite-static-analysis:2.12.0")
+}

lib-extra/src/test/java/com/diffplug/spotless/extra/eclipse/EclipseResourceHarness.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2024 DiffPlug
+ * Copyright 2016-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,8 +15,6 @@
  */
 package com.diffplug.spotless.extra.eclipse;
 
-import static org.assertj.core.api.Assertions.*;
-
 import java.io.File;
 import java.util.Arrays;
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2024 DiffPlug
+ * Copyright 2016-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,8 +24,6 @@
 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}";
 
 	public GrEclipseFormatterStepTest() {
 		super(GrEclipseFormatterStep.createBuilder(TestProvisioner.mavenCentral()));

lib/src/compatKtLint0Dot49Dot0/java/com/diffplug/spotless/glue/ktlint/compat/KtLintCompat0Dot49Dot0Adapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023-2024 DiffPlug
+ * Copyright 2023-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,9 +27,6 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import com.pinterest.ktlint.cli.ruleset.core.api.RuleSetProviderV3;
 import com.pinterest.ktlint.rule.engine.api.Code;
 import com.pinterest.ktlint.rule.engine.api.EditorConfigDefaults;
@@ -55,8 +52,6 @@
 
 public class KtLintCompat0Dot49Dot0Adapter implements KtLintCompatAdapter {
 
-	private static final Logger logger = LoggerFactory.getLogger(KtLintCompat0Dot49Dot0Adapter.class);
-
 	private static final List<EditorConfigProperty<?>> DEFAULT_EDITOR_CONFIG_PROPERTIES;
 
 	static {

lib/src/compatKtLint0Dot50Dot0/java/com/diffplug/spotless/glue/ktlint/compat/KtLintCompat0Dot50Dot0Adapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023-2024 DiffPlug
+ * Copyright 2023-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,9 +25,6 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import com.pinterest.ktlint.cli.ruleset.core.api.RuleSetProviderV3;
 import com.pinterest.ktlint.rule.engine.api.Code;
 import com.pinterest.ktlint.rule.engine.api.EditorConfigDefaults;
@@ -55,8 +52,6 @@
 
 public class KtLintCompat0Dot50Dot0Adapter implements KtLintCompatAdapter {
 
-	private static final Logger logger = LoggerFactory.getLogger(KtLintCompat0Dot50Dot0Adapter.class);
-
 	private static final List<EditorConfigProperty<?>> DEFAULT_EDITOR_CONFIG_PROPERTIES;
 
 	static {

lib/src/compatKtLint1Dot0Dot0/java/com/diffplug/spotless/glue/ktlint/compat/KtLintCompat1Dot0Dot0Adapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023-2024 DiffPlug
+ * Copyright 2023-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,9 +24,6 @@
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import com.pinterest.ktlint.cli.ruleset.core.api.RuleSetProviderV3;
 import com.pinterest.ktlint.rule.engine.api.Code;
 import com.pinterest.ktlint.rule.engine.api.EditorConfigDefaults;
@@ -54,8 +51,6 @@
 
 public class KtLintCompat1Dot0Dot0Adapter implements KtLintCompatAdapter {
 
-	private static final Logger logger = LoggerFactory.getLogger(KtLintCompat1Dot0Dot0Adapter.class);
-
 	private static final List<EditorConfigProperty<?>> DEFAULT_EDITOR_CONFIG_PROPERTIES;
 
 	static {

lib/src/gherkin/java/com/diffplug/spotless/glue/gherkin/GherkinUtilsFormatterFunc.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023 DiffPlug
+ * Copyright 2023-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,9 +15,6 @@
  */
 package com.diffplug.spotless.glue.gherkin;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
 import com.diffplug.spotless.FormatterFunc;
 import com.diffplug.spotless.gherkin.GherkinUtilsConfig;
 
@@ -30,7 +27,6 @@
 import io.cucumber.messages.types.SourceMediaType;
 
 public class GherkinUtilsFormatterFunc implements FormatterFunc {
-	private static final Logger LOGGER = LoggerFactory.getLogger(GherkinUtilsFormatterFunc.class);
 
 	private final GherkinUtilsConfig gherkinSimpleConfig;
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2022-2024 DiffPlug
+ * Copyright 2022-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -432,7 +432,6 @@ private static final class State implements Serializable {
 
 		// group 1 is the basename of the annotation.
 		private static final String annoNoArgRegex = "@(?:[A-Za-z_][A-Za-z0-9_.]*\\.)?([A-Za-z_][A-Za-z0-9_]*)";
-		private static final Pattern annoNoArgPattern = Pattern.compile(annoNoArgRegex);
 		// 3 non-empty cases:  ()  (".*")  (.*)
 		private static final String annoArgRegex = "(?:\\(\\)|\\(\"[^\"]*\"\\)|\\([^\")][^)]*\\))?";
 		// group 1 is the basename of the annotation.

lib/src/main/java/com/diffplug/spotless/kotlin/DiktatStep.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2021-2024 DiffPlug
+ * Copyright 2021-2025 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,7 +18,7 @@
 import java.io.File;
 import java.io.Serializable;
 import java.lang.reflect.Constructor;
-import java.util.*;
+import java.util.Objects;
 
 import javax.annotation.Nullable;
 

lib/src/main/java/com/diffplug/spotless/npm/NpmFormatterStepStateBase.java

@@ -41,8 +41,6 @@ abstract class NpmFormatterStepStateBase implements Serializable {
 
 	private static final Logger logger = LoggerFactory.getLogger(NpmFormatterStepStateBase.class);
 
-	private static final TimedLogger timedLogger = TimedLogger.forLogger(logger);
-
 	private static final long serialVersionUID = 1460749955865959948L;
 
 	private final String stepName;