Make RemoveUnusedImportsStep round-trippable

Author: Goooler

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

@@ -131,7 +131,7 @@ private State equalityState() {
 		return new State(jarState.get(), version, sourceJdkVersion, included, excluded, includeDraft);
 	}
 
-	static final class State implements Serializable {
+	private static final class State implements Serializable {
 		private static final long serialVersionUID = 1L;
 
 		private final JarState jarState;

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

@@ -88,17 +88,34 @@ public static FormatterStep create(String groupArtifact, String version, String
 
 	/** Creates a step which formats everything - groupArtifact, code, import order, and unused imports - and optionally reflows long strings. */
 	public static FormatterStep create(String groupArtifact, String version, String style, Provisioner provisioner, boolean reflowLongStrings, boolean reorderImports, boolean formatJavadoc) {
+		return createInternally(groupArtifact, version, style, provisioner, reflowLongStrings, reorderImports, formatJavadoc, false);
+	}
+
+	static FormatterStep createRemoveUnusedImportsOnly(Provisioner provisioner) {
+		return createInternally(MAVEN_COORDINATE, defaultVersion(), defaultStyle(), provisioner, defaultReflowLongStrings(), defaultReorderImports(), defaultFormatJavadoc(), true);
+	}
+
+	private static FormatterStep createInternally(String groupArtifact, String version, String style, Provisioner provisioner, boolean reflowLongStrings, boolean reorderImports, boolean formatJavadoc, boolean removeImports) {
 		Objects.requireNonNull(groupArtifact, "groupArtifact");
 		if (groupArtifact.chars().filter(ch -> ch == ':').count() != 1) {
 			throw new IllegalArgumentException("groupArtifact must be in the form 'groupId:artifactId'");
 		}
 		Objects.requireNonNull(version, "version");
 		Objects.requireNonNull(style, "style");
 		Objects.requireNonNull(provisioner, "provisioner");
-		return FormatterStep.create(NAME,
-				new GoogleJavaFormatStep(JarState.promise(() -> JarState.from(groupArtifact + ":" + version, provisioner)), version, style, reflowLongStrings, reorderImports, formatJavadoc),
-				GoogleJavaFormatStep::equalityState,
-				State::createFormat);
+
+		GoogleJavaFormatStep step = new GoogleJavaFormatStep(JarState.promise(() -> JarState.from(groupArtifact + ":" + version, provisioner)), version, style, reflowLongStrings, reorderImports, formatJavadoc);
+		if (removeImports) {
+			return FormatterStep.create(NAME,
+					step,
+					GoogleJavaFormatStep::equalityState,
+					State::createRemoveUnusedImportsOnly);
+		} else {
+			return FormatterStep.create(NAME,
+					step,
+					GoogleJavaFormatStep::equalityState,
+					State::createFormat);
+		}
 	}
 
 	private static final Jvm.Support<String> JVM_SUPPORT = Jvm.<String> support(NAME)
@@ -136,7 +153,7 @@ private State equalityState() {
 		return new State(version, style, jarState.get(), reflowLongStrings, reorderImports, formatJavadoc);
 	}
 
-	static final class State implements Serializable {
+	private static final class State implements Serializable {
 		private static final long serialVersionUID = 1L;
 
 		private final JarState jarState;
@@ -146,10 +163,6 @@ static final class State implements Serializable {
 		private final boolean reorderImports;
 		private final boolean formatJavadoc;
 
-		State(String version, JarState jarState) {
-			this(version, DEFAULT_STYLE, jarState, DEFAULT_REFLOW_LONG_STRINGS, DEFAULT_REORDER_IMPORTS, DEFAULT_FORMAT_JAVADOC);
-		}
-
 		State(String version,
 				String style,
 				JarState jarState,

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2023 DiffPlug
+ * Copyright 2016-2024 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -15,15 +15,17 @@
  */
 package com.diffplug.spotless.java;
 
-import java.util.Arrays;
+import java.util.List;
 import java.util.Objects;
 
 import com.diffplug.spotless.FormatterStep;
 import com.diffplug.spotless.Provisioner;
+import com.diffplug.spotless.RoundedStep;
 
 /** Uses google-java-format or cleanthat.UnnecessaryImport, but only to remove unused imports. */
-public class RemoveUnusedImportsStep {
-	static final String NAME = "removeUnusedImports";
+public class RemoveUnusedImportsStep implements RoundedStep {
+	private static final long serialVersionUID = 1L;
+	private static final String NAME = "removeUnusedImports";
 
 	static final String GJF = "google-java-format";
 	static final String CLEANTHAT = "cleanthat-javaparser-unnecessaryimport";
@@ -34,7 +36,7 @@ public class RemoveUnusedImportsStep {
 	// prevent direct instantiation
 	private RemoveUnusedImportsStep() {}
 
-	public static final String defaultFormatter() {
+	public static String defaultFormatter() {
 		return GJF;
 	}
 
@@ -45,16 +47,12 @@ public static FormatterStep create(Provisioner provisioner) {
 
 	public static FormatterStep create(String unusedImportRemover, Provisioner provisioner) {
 		Objects.requireNonNull(provisioner, "provisioner");
-
-		if (GJF.equals(unusedImportRemover)) {
-			return FormatterStep.createLazy(NAME,
-					() -> new GoogleJavaFormatStep.State(NAME, GoogleJavaFormatStep.defaultVersion(), provisioner),
-					GoogleJavaFormatStep.State::createRemoveUnusedImportsOnly);
-		} else if (CLEANTHAT.equals(unusedImportRemover)) {
-			return FormatterStep.createLazy(NAME,
-					() -> new CleanthatJavaStep.State(NAME, CleanthatJavaStep.defaultGroupArtifact(), CleanthatJavaStep.defaultVersion(), "99.9", Arrays.asList(CLEANTHAT_MUTATOR), Arrays.asList(), false, provisioner),
-					CleanthatJavaStep.State::createFormat);
-		} else {
+		switch (unusedImportRemover) {
+		case GJF:
+			return GoogleJavaFormatStep.createRemoveUnusedImportsOnly(provisioner);
+		case CLEANTHAT:
+			return CleanthatJavaStep.create(CleanthatJavaStep.defaultGroupArtifact(), CleanthatJavaStep.defaultVersion(), "99.9", List.of(CLEANTHAT_MUTATOR), List.of(), false, provisioner);
+		default:
 			throw new IllegalArgumentException("Invalid unusedImportRemover: " + unusedImportRemover);
 		}
 	}