Support ktfmt dropbox style in maven plugin

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

@@ -79,6 +79,10 @@ public static String defaultVersion() {
 		return DEFAULT_VERSION;
 	}
 
+	public static String defaultStyle() {
+		return Style.DEFAULT.name();
+	}
+
 	static final class State implements Serializable {
 		private static final long serialVersionUID = 1L;
 

plugin-gradle/src/main/java/com/diffplug/gradle/spotless/KotlinExtension.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2020 DiffPlug
+ * Copyright 2016-2021 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -109,7 +109,11 @@ public class KtfmtConfig {
 		}
 
 		public void dropboxStyle() {
-			style = Style.DROPBOX;
+			style(Style.DROPBOX);
+		}
+
+		public void style(Style style) {
+			this.style = style;
 			replaceStep(createStep());
 		}
 

plugin-maven/CHANGES.md

@@ -7,6 +7,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 * Added support for eclipse-cdt 4.18.0.
 * Added support for eclipse-jdt 4.18.0.
 * Added support for eclipse-wtp 4.18.0.
+* Added ability to specify dropbox style for ktfmt `<style>DROPBOX</style>` ([#764](https://github.com/diffplug/spotless/pull/764))
 ### Changed
 * Updated default eclipse-jdt from 4.17.0 to 4.18.0.
 * Updated default eclipse-wtp from 4.17.0 to 4.18.0.

plugin-maven/README.md

@@ -306,7 +306,8 @@ Groovy-Eclipse formatting errors/warnings lead per default to a build failure. T
 
 ```xml
 <ktfmt>
-  <version>0.13</version> <!-- optional -->
+  <version>0.18</version> <!-- optional -->
+  <style>DEFAULT</style> <!-- optional, other option is DROPBOX -->
 </ktfmt>
 ```
 

plugin-maven/src/main/java/com/diffplug/spotless/maven/kotlin/Ktfmt.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 DiffPlug
+ * Copyright 2016-2021 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,6 +19,7 @@
 
 import com.diffplug.spotless.FormatterStep;
 import com.diffplug.spotless.kotlin.KtfmtStep;
+import com.diffplug.spotless.kotlin.KtfmtStep.Style;
 import com.diffplug.spotless.maven.FormatterStepConfig;
 import com.diffplug.spotless.maven.FormatterStepFactory;
 
@@ -27,9 +28,13 @@ public class Ktfmt implements FormatterStepFactory {
 	@Parameter
 	private String version;
 
+	@Parameter
+	private String style;
+
 	@Override
 	public FormatterStep newFormatterStep(FormatterStepConfig config) {
 		String version = this.version != null ? this.version : KtfmtStep.defaultVersion();
-		return KtfmtStep.create(version, config.getProvisioner());
+		String style = this.style != null ? this.style : KtfmtStep.defaultStyle();
+		return KtfmtStep.create(version, config.getProvisioner(), Style.valueOf(style));
 	}
 }

plugin-maven/src/test/java/com/diffplug/spotless/maven/kotlin/KtfmtTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2020 DiffPlug
+ * Copyright 2016-2021 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -39,4 +39,16 @@ public void testKtfmt() throws Exception {
 		assertFile(path1).sameAsResource("kotlin/ktfmt/basic.clean");
 		assertFile(path2).sameAsResource("kotlin/ktfmt/basic.clean");
 	}
+
+	@Test
+	public void testKtfmtStyle() throws Exception {
+		// ktfmt's dependency, google-java-format 1.8 requires a minimum of JRE 11+.
+		JreVersion.assume11OrGreater();
+
+		writePomWithKotlinSteps("<ktfmt><style>DROPBOX</style></ktfmt>");
+
+		setFile("src/main/kotlin/main.kt").toResource("kotlin/ktfmt/basic.dirty");
+		mavenRunner().withArguments("spotless:apply").runNoError();
+		assertFile("src/main/kotlin/main.kt").sameAsResource("kotlin/ktfmt/basic-dropboxstyle.clean");
+	}
 }