Use palantir-java-format as default formatter in RemoveUnusedImportsStep (#2541)

Author: nedtwigg

CHANGES.md

@@ -13,6 +13,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 ### Added
 * Support for `idea` ([#2020](https://github.com/diffplug/spotless/pull/2020), [#2535](https://github.com/diffplug/spotless/pull/2535))
 * Add support for removing wildcard imports via `removeWildcardImports` step. ([#2517](https://github.com/diffplug/spotless/pull/2517))
+* Use `palantir-java-format` as default formatter in `RemoveUnusedImportsStep`. ([#2541](https://github.com/diffplug/spotless/pull/2541))
 
 ### Fixed
 * Make sure npm-based formatters use the correct `node_modules` directory when running in parallel. ([#2542](https://github.com/diffplug/spotless/pull/2542))

lib/src/main/java/com/diffplug/spotless/java/RemoveUnusedImportsStep.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.
@@ -22,12 +22,12 @@
 import com.diffplug.spotless.FormatterStep;
 import com.diffplug.spotless.Provisioner;
 
-/** Uses google-java-format or cleanthat.UnnecessaryImport, but only to remove unused imports. */
+/** Uses palantir-java-format or cleanthat.UnnecessaryImport, but only to remove unused imports. */
 public class RemoveUnusedImportsStep implements Serializable {
 	private static final long serialVersionUID = 1L;
 	static final String NAME = "removeUnusedImports";
 
-	static final String GJF = "google-java-format";
+	static final String DEFAULT_FORMATTER = "palantir-java-format";
 	static final String CLEANTHAT = "cleanthat-javaparser-unnecessaryimport";
 
 	// https://github.com/solven-eu/cleanthat/blob/master/java/src/main/java/eu/solven/cleanthat/engine/java/refactorer/mutators/UnnecessaryImport.java
@@ -37,18 +37,17 @@ public class RemoveUnusedImportsStep implements Serializable {
 	private RemoveUnusedImportsStep() {}
 
 	public static String defaultFormatter() {
-		return GJF;
+		return DEFAULT_FORMATTER;
 	}
 
 	public static FormatterStep create(Provisioner provisioner) {
-		// The default importRemover is GJF
-		return create(GJF, provisioner);
+		return create(DEFAULT_FORMATTER, provisioner);
 	}
 
 	public static FormatterStep create(String unusedImportRemover, Provisioner provisioner) {
 		Objects.requireNonNull(provisioner, "provisioner");
 		switch (unusedImportRemover) {
-		case GJF:
+		case DEFAULT_FORMATTER:
 			return GoogleJavaFormatStep.createRemoveUnusedImportsOnly(provisioner);
 		case CLEANTHAT:
 			return CleanthatJavaStep.createWithStepName(NAME, CleanthatJavaStep.defaultGroupArtifact(), CleanthatJavaStep.defaultVersion(), "99.9", List.of(CLEANTHAT_MUTATOR), List.of(), false, provisioner);

plugin-maven/src/test/java/com/diffplug/spotless/java/RemoveUnusedImportsStepTest.java

@@ -0,0 +1,73 @@
+/*
+ * 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.
+ * 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 static com.diffplug.spotless.java.RemoveUnusedImportsStep.DEFAULT_FORMATTER;
+import static com.diffplug.spotless.java.RemoveUnusedImportsStep.NAME;
+import static com.diffplug.spotless.java.RemoveUnusedImportsStep.defaultFormatter;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.Collections;
+
+import org.junit.jupiter.api.Test;
+
+import com.diffplug.spotless.maven.MavenIntegrationHarness;
+
+class RemoveUnusedImportsStepTest extends MavenIntegrationHarness {
+
+	@Test
+	void testRemoveUnusedImports() throws Exception {
+		writePomWithJavaSteps("<removeUnusedImports/>");
+
+		String path = "src/main/java/test.java";
+		setFile(path).toResource("java/removeunusedimports/JavaCodeWithPackageUnformatted.test");
+		mavenRunner().withArguments("spotless:apply").runNoError();
+		assertFile(path).sameAsResource("java/removeunusedimports/JavaCodeWithPackageFormatted.test");
+	}
+
+	@Test
+	void testDefaults() {
+		assertEquals("palantir-java-format", defaultFormatter());
+		assertEquals("palantir-java-format", DEFAULT_FORMATTER);
+		assertEquals("removeUnusedImports", NAME);
+	}
+
+	@Test
+	void testCreateWithDefaultFormatter() {
+		assertEquals(NAME, RemoveUnusedImportsStep.create((groupArtifact, version) -> Collections.emptySet()).getName());
+	}
+
+	@Test
+	void testCreateWithPalantirFormatter() {
+		assertEquals(NAME, RemoveUnusedImportsStep.create("palantir-java-format", (groupArtifact, version) -> Collections.emptySet()).getName());
+	}
+
+	@Test
+	void testCreateWithCleanthatFormatter() {
+		assertEquals(NAME, RemoveUnusedImportsStep.create("cleanthat-javaparser-unnecessaryimport", (groupArtifact, version) -> Collections.emptySet()).getName());
+	}
+
+	@Test
+	void testCreateWithInvalidFormatter() {
+		assertThrows(IllegalArgumentException.class, () -> RemoveUnusedImportsStep.create("invalid-formatter", (groupArtifact, version) -> Collections.emptySet()));
+	}
+
+	@Test
+	void testCreateWithNullProvisioner() {
+		assertThrows(NullPointerException.class, () -> RemoveUnusedImportsStep.create("palantir-java-format", null));
+	}
+}

plugin-maven/src/test/java/com/diffplug/spotless/maven/java/RemoveUnusedImportsStepTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2023 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.
@@ -25,7 +25,7 @@
 class RemoveUnusedImportsStep_withGoogleJavaFormatTest {
 	@Test
 	void behavior() throws Exception {
-		FormatterStep step = RemoveUnusedImportsStep.create(RemoveUnusedImportsStep.GJF, TestProvisioner.mavenCentral());
+		FormatterStep step = RemoveUnusedImportsStep.create(RemoveUnusedImportsStep.DEFAULT_FORMATTER, TestProvisioner.mavenCentral());
 		StepHarness.forStep(step)
 				.testResource("java/removeunusedimports/JavaCodeUnformatted.test", "java/removeunusedimports/JavaCodeFormatted.test")
 				.testResource("java/removeunusedimports/JavaCodeWithLicenseUnformatted.test", "java/removeunusedimports/JavaCodeWithLicenseFormatted.test")
@@ -48,7 +48,7 @@ protected void setupTest(API api) {
 
 			@Override
 			protected FormatterStep create() {
-				return RemoveUnusedImportsStep.create(RemoveUnusedImportsStep.GJF, TestProvisioner.mavenCentral());
+				return RemoveUnusedImportsStep.create(RemoveUnusedImportsStep.DEFAULT_FORMATTER, TestProvisioner.mavenCentral());
 			}
 		}.testEquals();
 	}