Adds ktlint linting for Gradle Kotlin DSL files

.gitignore

@@ -97,7 +97,7 @@ local.properties
 ## Plugin-specific files:
 
 # IntelliJ
-/out/
+out/
 
 # mpeltonen/sbt-idea plugin
 .idea_modules/

README.md

@@ -82,6 +82,7 @@ lib('scala.ScalaFmtStep')                        +'{{yes}}       | {{no}}
 * Formatting by Eclipse
 	+ Special thanks to [Mateusz Matela](https://waynebeaton.wordpress.com/2015/03/15/great-fixes-for-mars-winners-part-i/) for huge improvements to the eclipse code formatter!
 * Thanks to [Stanley Shyiko](https://github.com/shyiko) for his help integrating [ktlint](https://github.com/shyiko/ktlint).
+* Thanks to [Jonathan Leitschuh](https://github.com/JLLeitschuh) for adding [ktlint](https://github.com/shyiko/ktlint) support for [Gradle Kotlin DSL](https://github.com/gradle/kotlin-dsl) files.
 * Originally forked from [gradle-format-plugin](https://github.com/youribonnaffe/gradle-format-plugin) by Youri Bonnaffé.
 * Thanks to Gábor Bernát for improvements to logging and multi-project support.
 * Thanks to Andrew Oberstar for improvements to formatting java source in non-java source sets. [PR #60](https://github.com/diffplug/spotless/pull/60).

plugin-gradle/CHANGES.md

@@ -4,6 +4,7 @@
 
 * Changed `importOrder` interface from array to varargs ([#125](https://github.com/diffplug/spotless/issues/125))
 * The `kotlin` extension was mis-spelled as `kotin`.
+* Added `kotlinGradle` method to `SpotlessExtension` for linting [Gradle Kotlin DSL](https://github.com/gradle/kotlin-dsl) files with [ktlint](https://github.com/shyiko/ktlint). ([#115](https://github.com/diffplug/spotless/issues/115))
 
 ### Version 3.4.1 - July 11th 2017 ([javadoc](https://diffplug.github.io/spotless/javadoc/spotless-plugin-gradle/3.4.1/), [jcenter](https://bintray.com/diffplug/opensource/spotless-plugin-gradle/3.4.1))
 

plugin-gradle/README.md

@@ -226,8 +226,18 @@ spotless {
 		licenseHeader '/* Licensed under Apache-2.0 */'	// License header
 		licenseHeaderFile 'path-to-license-file'		// License header file
 	}
+	kotlinGradle {
+		// same as kotlin, but for .gradle.kts files (defaults to '*.gradle.kts')
+		target '*.gradle.kts', 'additionalScripts/*.gradle.kts'
+
+		ktlint()
+
+		// doesn't support licenseHeader, because scripts don't have a package statement
+		// to clearly mark where the license should go
+	}
 }
 ```
+
 <a name="custom"></a>
 
 ## Custom rules

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

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2016 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.gradle.spotless;
+
+import java.util.Objects;
+
+import com.diffplug.spotless.kotlin.KtLintStep;
+
+public class KotlinGradleExtension extends FormatExtension {
+	private static final String GRADLE_KOTLIN_DSL_FILE_EXTENSION = "*.gradle.kts";
+
+	static final String NAME = "kotlinGradle";
+
+	public KotlinGradleExtension(SpotlessExtension rootExtension) {
+		super(rootExtension);
+	}
+
+	/** Adds the specified version of [ktlint](https://github.com/shyiko/ktlint). */
+	public void ktlint(String version) {
+		Objects.requireNonNull(version, "version");
+		addStep(KtLintStep.create(version, GradleProvisioner.fromProject(getProject())));
+	}
+
+	public void ktlint() {
+		ktlint(KtLintStep.defaultVersion());
+	}
+
+	@Override
+	protected void setupTask(SpotlessTask task) {
+		if (target == null) {
+			target = parseTarget(GRADLE_KOTLIN_DSL_FILE_EXTENSION);
+		}
+		super.setupTask(task);
+	}
+}

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

@@ -91,6 +91,12 @@ public void kotlin(Action<KotlinExtension> closure) {
 		configure(KotlinExtension.NAME, KotlinExtension.class, closure);
 	}
 
+	/** Configures the special Gradle Kotlin DSL specific extension. */
+	public void kotlinGradle(Action<KotlinGradleExtension> closure) {
+		requireNonNull(closure);
+		configure(KotlinGradleExtension.NAME, KotlinGradleExtension.class, closure);
+	}
+
 	/** Configures the special freshmark-specific extension. */
 	public void freshmark(Action<FreshMarkExtension> closure) {
 		requireNonNull(closure);

plugin-gradle/src/test/java/com/diffplug/gradle/spotless/KotlinGradleExtensionTest.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2016 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.gradle.spotless;
+
+import java.io.IOException;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class KotlinGradleExtensionTest extends GradleIntegrationTest {
+	@Test
+	public void integration() throws IOException {
+		testInDirectory(null);
+	}
+
+	@Test
+	public void integration_script_in_subdir() throws IOException {
+		testInDirectory("companionScripts");
+	}
+
+	private void testInDirectory(final String directory) throws IOException {
+		write("build.gradle",
+				"plugins {",
+				"    id 'nebula.kotlin' version '1.0.6'",
+				"    id 'com.diffplug.gradle.spotless'",
+				"}",
+				"repositories { mavenCentral() }",
+				"spotless {",
+				"    kotlinGradle {",
+				"        ktlint()",
+				"        target '**/*.gradle.kts'",
+				"    }",
+				"}");
+		String filePath = "configuration.gradle.kts";
+		if (directory != null) {
+			filePath = directory + "/" + filePath;
+		}
+		write(filePath,
+				getTestResource("kotlin/ktlint/basic.dirty"));
+		gradleRunner().withArguments("spotlessApply").build();
+		String result = read(filePath);
+		String formatted = getTestResource("kotlin/ktlint/basic.clean");
+		Assert.assertEquals(formatted, result);
+	}
+
+	@Test
+	public void integration_default() throws IOException {
+		write("build.gradle",
+				"plugins {",
+				"    id 'nebula.kotlin' version '1.0.6'",
+				"    id 'com.diffplug.gradle.spotless'",
+				"}",
+				"repositories { mavenCentral() }",
+				"spotless {",
+				"    kotlinGradle {",
+				"        ktlint()",
+				"    }",
+				"}");
+		write("configuration.gradle.kts",
+				getTestResource("kotlin/ktlint/basic.dirty"));
+		gradleRunner().withArguments("spotlessApply").build();
+		String result = read("configuration.gradle.kts");
+		String formatted = getTestResource("kotlin/ktlint/basic.clean");
+		Assert.assertEquals(formatted, result);
+	}
+}