Support for google-java-format's style option (AOSP style)

CHANGES.md

@@ -10,6 +10,7 @@ You might be looking for:
 * Updated default ktlint from 0.6.1 to 0.14.0
 * Updated default google-java-format from 1.3 to 1.5
 * Updated default eclipse-jdt from 4.7.1 to 4.7.2
+* Added a configuration option to `googleJavaFormat` to switch the formatter style ([#193](https://github.com/diffplug/spotless/pull/193))
 
 ### Version 1.8.0 - January 2nd 2018 (javadoc [lib](https://diffplug.github.io/spotless/javadoc/spotless-lib/1.8.0/) [lib-extra](https://diffplug.github.io/spotless/javadoc/spotless-lib-extra/1.8.0/), artifact [lib]([jcenter](https://bintray.com/diffplug/opensource/spotless-lib), [lib-extra]([jcenter](https://bintray.com/diffplug/opensource/spotless-lib-extra)))
 

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

@@ -32,11 +32,19 @@ public class GoogleJavaFormatStep {
 	private GoogleJavaFormatStep() {}
 
 	private static final String DEFAULT_VERSION = "1.5";
+	private static final String DEFAULT_STYLE = "GOOGLE";
 	static final String NAME = "google-java-format";
 	static final String MAVEN_COORDINATE = "com.google.googlejavaformat:google-java-format:";
 	static final String FORMATTER_CLASS = "com.google.googlejavaformat.java.Formatter";
 	static final String FORMATTER_METHOD = "formatSource";
 
+	private static final String OPTIONS_CLASS = "com.google.googlejavaformat.java.JavaFormatterOptions";
+	private static final String OPTIONS_BUILDER_METHOD = "builder";
+	private static final String OPTIONS_BUILDER_CLASS = "com.google.googlejavaformat.java.JavaFormatterOptions$Builder";
+	private static final String OPTIONS_BUILDER_STYLE_METHOD = "style";
+	private static final String OPTIONS_BUILDER_BUILD_METHOD = "build";
+	private static final String OPTIONS_Style = "com.google.googlejavaformat.java.JavaFormatterOptions$Style";
+
 	private static final String REMOVE_UNUSED_CLASS = "com.google.googlejavaformat.java.RemoveUnusedImports";
 	private static final String REMOVE_UNUSED_METHOD = "removeUnusedImports";
 
@@ -53,38 +61,67 @@ public static FormatterStep create(Provisioner provisioner) {
 
 	/** Creates a step which formats everything - code, import order, and unused imports. */
 	public static FormatterStep create(String version, Provisioner provisioner) {
+		return create(version, DEFAULT_STYLE, provisioner);
+	}
+
+	/** Creates a step which formats everything - code, import order, and unused imports. */
+	public static FormatterStep create(String version, String style, Provisioner provisioner) {
 		Objects.requireNonNull(version, "version");
+		Objects.requireNonNull(style, "style");
 		Objects.requireNonNull(provisioner, "provisioner");
 		return FormatterStep.createLazy(NAME,
-				() -> new State(NAME, version, provisioner),
+				() -> new State(NAME, version, style, provisioner),
 				State::createFormat);
 	}
 
 	public static String defaultVersion() {
 		return DEFAULT_VERSION;
 	}
 
+	public static String defaultStyle() {
+		return DEFAULT_STYLE;
+	}
+
 	static final class State implements Serializable {
 		private static final long serialVersionUID = 1L;
 
 		/** The jar that contains the eclipse formatter. */
 		final JarState jarState;
 		final String stepName;
 		final String version;
+		final String style;
 
 		State(String stepName, String version, Provisioner provisioner) throws IOException {
+			this(stepName, version, DEFAULT_STYLE, provisioner);
+		}
+
+		State(String stepName, String version, String style, Provisioner provisioner) throws IOException {
 			this.jarState = JarState.from(MAVEN_COORDINATE + version, provisioner);
 			this.stepName = stepName;
 			this.version = version;
+			this.style = style;
 		}
 
 		@SuppressWarnings({"unchecked", "rawtypes"})
 		FormatterFunc createFormat() throws Exception {
 			ClassLoader classLoader = jarState.getClassLoader();
 
 			// instantiate the formatter and get its format method
+			Class<?> optionsClass = classLoader.loadClass(OPTIONS_CLASS);
+			Class<?> optionsBuilderClass = classLoader.loadClass(OPTIONS_BUILDER_CLASS);
+			Method optionsBuilderMethod = optionsClass.getMethod(OPTIONS_BUILDER_METHOD);
+			Object optionsBuilder = optionsBuilderMethod.invoke(null);
+
+			Class<?> optionsStyleClass = classLoader.loadClass(OPTIONS_Style);
+			Object styleConstant = Enum.valueOf((Class<Enum>) optionsStyleClass, style);
+			Method optionsBuilderStyleMethod = optionsBuilderClass.getMethod(OPTIONS_BUILDER_STYLE_METHOD, optionsStyleClass);
+			optionsBuilderStyleMethod.invoke(optionsBuilder, styleConstant);
+
+			Method optionsBuilderBuildMethod = optionsBuilderClass.getMethod(OPTIONS_BUILDER_BUILD_METHOD);
+			Object options = optionsBuilderBuildMethod.invoke(optionsBuilder);
+
 			Class<?> formatterClazz = classLoader.loadClass(FORMATTER_CLASS);
-			Object formatter = formatterClazz.getConstructor().newInstance();
+			Object formatter = formatterClazz.getConstructor(optionsClass).newInstance(options);
 			Method formatterMethod = formatterClazz.getMethod(FORMATTER_METHOD, String.class);
 
 			Class<?> removeUnusedClass = classLoader.loadClass(REMOVE_UNUSED_CLASS);

plugin-gradle/CHANGES.md

@@ -5,6 +5,8 @@
 * Updated default ktlint from 0.6.1 to 0.14.0
 * Updated default google-java-format from 1.3 to 1.5
 * Updated default eclipse-jdt from 4.7.1 to 4.7.2
+* Added a configuration option to `googleJavaFormat` to switch the formatter style ([#193](https://github.com/diffplug/spotless/pull/193))
+  + Use `googleJavaFormat().aosp()` to use AOSP-compliant style (4-space indentation) instead of the default Google Style
 
 ### Version 3.8.0 - January 2nd 2018 ([javadoc](https://diffplug.github.io/spotless/javadoc/spotless-plugin-gradle/3.8.0/), [jcenter](https://bintray.com/diffplug/opensource/spotless-plugin-gradle/3.8.0))
 

plugin-gradle/README.md

@@ -147,7 +147,9 @@ spotless {
 ```gradle
 spotless {
   java {
-    googleJavaFormat() // googleJavaFormat('1.1') to specify a specific version
+    googleJavaFormat()
+    // optional: you can specify a specific version and/or switch to AOSP style
+    googleJavaFormat('1.1').aosp()
     // you can then layer other format steps, such as
     licenseHeaderFile 'spotless.license.java'
   }

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

@@ -100,8 +100,8 @@ public void removeUnusedImports() {
 	}
 
 	/** Uses the [google-java-format](https://github.com/google/google-java-format) jar to format source code. */
-	public void googleJavaFormat() {
-		googleJavaFormat(GoogleJavaFormatStep.defaultVersion());
+	public GoogleJavaFormatConfig googleJavaFormat() {
+		return googleJavaFormat(GoogleJavaFormatStep.defaultVersion());
 	}
 
 	/**
@@ -110,9 +110,36 @@ public void googleJavaFormat() {
 	 * Limited to published versions.  See [issue #33](https://github.com/diffplug/spotless/issues/33#issuecomment-252315095)
 	 * for an workaround for using snapshot versions.
 	 */
-	public void googleJavaFormat(String version) {
+	public GoogleJavaFormatConfig googleJavaFormat(String version) {
 		Objects.requireNonNull(version);
-		addStep(GoogleJavaFormatStep.create(version, GradleProvisioner.fromProject(getProject())));
+		return new GoogleJavaFormatConfig(version);
+	}
+
+	public class GoogleJavaFormatConfig {
+		final String version;
+		String style;
+
+		GoogleJavaFormatConfig(String version) {
+			this.version = Objects.requireNonNull(version);
+			this.style = GoogleJavaFormatStep.defaultStyle();
+			addStep(createStep());
+		}
+
+		public void style(String style) {
+			this.style = Objects.requireNonNull(style);
+			replaceStep(createStep());
+		}
+
+		public void aosp() {
+			style("AOSP");
+		}
+
+		private FormatterStep createStep() {
+			Project project = getProject();
+			return GoogleJavaFormatStep.create(version,
+					style,
+					GradleProvisioner.fromProject(project));
+		}
 	}
 
 	public EclipseConfig eclipse() {

testlib/src/test/java/com/diffplug/spotless/java/GoogleJavaFormatStepTest.java

@@ -36,10 +36,21 @@ public void behavior() throws Exception {
 				.testResource("java/googlejavaformat/JavaCodeWithPackageUnformatted.test", "java/googlejavaformat/JavaCodeWithPackageFormatted.test");
 	}
 
+	@Test
+	public void behaviorWithAospStyle() throws Exception {
+		FormatterStep step = GoogleJavaFormatStep.create("1.2", "AOSP", TestProvisioner.mavenCentral());
+		StepHarness.forStep(step)
+				.testResource("java/googlejavaformat/JavaCodeUnformatted.test", "java/googlejavaformat/JavaCodeFormattedAOSP.test")
+				.testResource("java/googlejavaformat/JavaCodeWithLicenseUnformatted.test", "java/googlejavaformat/JavaCodeWithLicenseFormattedAOSP.test")
+				.testResource("java/googlejavaformat/JavaCodeWithLicensePackageUnformatted.test", "java/googlejavaformat/JavaCodeWithLicensePackageFormattedAOSP.test")
+				.testResource("java/googlejavaformat/JavaCodeWithPackageUnformatted.test", "java/googlejavaformat/JavaCodeWithPackageFormattedAOSP.test");
+	}
+
 	@Test
 	public void equality() throws Exception {
 		new SerializableEqualityTester() {
 			String version = "1.2";
+			String style = "";
 
 			@Override
 			protected void setupTest(API api) {
@@ -48,12 +59,15 @@ protected void setupTest(API api) {
 				// change the version, and it's different
 				version = "1.1";
 				api.areDifferentThan();
+				// change the style, and it's different
+				style = "AOSP";
+				api.areDifferentThan();
 			}
 
 			@Override
 			protected FormatterStep create() {
 				String finalVersion = this.version;
-				return GoogleJavaFormatStep.create(finalVersion, TestProvisioner.mavenCentral());
+				return GoogleJavaFormatStep.create(finalVersion, style, TestProvisioner.mavenCentral());
 			}
 		}.testEquals();
 	}

testlib/src/test/resources/java/googlejavaformat/JavaCodeFormattedAOSP.test

@@ -0,0 +1,11 @@
+
+import mylib.UsedA;
+import mylib.UsedB;
+
+public class Java {
+    public static void main(String[] args) {
+        System.out.println("hello");
+        UsedB.someMethod();
+        UsedA.someMethod();
+    }
+}

testlib/src/test/resources/java/googlejavaformat/JavaCodeWithLicenseFormattedAOSP.test

@@ -0,0 +1,15 @@
+/*
+ * Some license stuff.
+ * Very official.
+ */
+
+import mylib.UsedA;
+import mylib.UsedB;
+
+public class Java {
+    public static void main(String[] args) {
+        System.out.println("hello");
+        UsedB.someMethod();
+        UsedA.someMethod();
+    }
+}

testlib/src/test/resources/java/googlejavaformat/JavaCodeWithLicensePackageFormattedAOSP.test

@@ -0,0 +1,12 @@
+package hello.world;
+
+import mylib.UsedA;
+import mylib.UsedB;
+
+public class Java {
+    public static void main(String[] args) {
+        System.out.println("hello");
+        UsedB.someMethod();
+        UsedA.someMethod();
+    }
+}

testlib/src/test/resources/java/googlejavaformat/JavaCodeWithPackageFormattedAOSP.test

@@ -0,0 +1,12 @@
+package hello.world;
+
+import mylib.UsedA;
+import mylib.UsedB;
+
+public class Java {
+    public static void main(String[] args) {
+        System.out.println("hello");
+        UsedB.someMethod();
+        UsedA.someMethod();
+    }
+}