Support google-java-format's skip-reflowing-long-strings option (#929)

Author: nedtwigg

CHANGES.md

@@ -10,6 +10,8 @@ This document is intended for Spotless developers.
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Added
+* Added support for `google-java-format`'s `skip-reflowing-long-strings` option ([#929](https://github.com/diffplug/spotless/pull/929))
 
 ## [2.15.3] - 2021-08-20
 ### Changed

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

@@ -27,6 +27,7 @@
 import com.diffplug.spotless.JarState;
 import com.diffplug.spotless.LineEnding;
 import com.diffplug.spotless.Provisioner;
+import com.diffplug.spotless.ThrowingEx.BiFunction;
 import com.diffplug.spotless.ThrowingEx.Function;
 
 /** Wraps up <a href="https://github.com/google/google-java-format">google-java-format</a> as a FormatterStep. */
@@ -35,6 +36,7 @@ public class GoogleJavaFormatStep {
 	private GoogleJavaFormatStep() {}
 
 	private static final String DEFAULT_STYLE = "GOOGLE";
+	private static final boolean DEFAULT_REFLOW_LONG_STRINGS = false;
 	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";
@@ -56,6 +58,9 @@ private GoogleJavaFormatStep() {}
 	private static final String IMPORT_ORDERER_CLASS = "com.google.googlejavaformat.java.ImportOrderer";
 	private static final String IMPORT_ORDERER_METHOD = "reorderImports";
 
+	private static final String STRING_WRAPPER_CLASS = "com.google.googlejavaformat.java.StringWrapper";
+	private static final String STRING_WRAPPER_METHOD = "wrap";
+
 	/** Creates a step which formats everything - code, import order, and unused imports. */
 	public static FormatterStep create(Provisioner provisioner) {
 		return create(defaultVersion(), provisioner);
@@ -68,11 +73,16 @@ public static FormatterStep create(String version, Provisioner provisioner) {
 
 	/** Creates a step which formats everything - code, import order, and unused imports. */
 	public static FormatterStep create(String version, String style, Provisioner provisioner) {
+		return create(version, style, provisioner, DEFAULT_REFLOW_LONG_STRINGS);
+	}
+
+	/** Creates a step which formats everything - code, import order, and unused imports - and optionally reflows long strings. */
+	public static FormatterStep create(String version, String style, Provisioner provisioner, boolean reflowLongStrings) {
 		Objects.requireNonNull(version, "version");
 		Objects.requireNonNull(style, "style");
 		Objects.requireNonNull(provisioner, "provisioner");
 		return FormatterStep.createLazy(NAME,
-				() -> new State(NAME, version, style, provisioner),
+				() -> new State(NAME, version, style, provisioner, reflowLongStrings),
 				State::createFormat);
 	}
 
@@ -106,6 +116,10 @@ public static String defaultStyle() {
 		return DEFAULT_STYLE;
 	}
 
+	public static boolean defaultReflowLongStrings() {
+		return DEFAULT_REFLOW_LONG_STRINGS;
+	}
+
 	static final class State implements Serializable {
 		private static final long serialVersionUID = 1L;
 
@@ -114,16 +128,22 @@ static final class State implements Serializable {
 		final String stepName;
 		final String version;
 		final String style;
+		final boolean reflowLongStrings;
 
 		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(stepName, version, style, provisioner, DEFAULT_REFLOW_LONG_STRINGS);
+		}
+
+		State(String stepName, String version, String style, Provisioner provisioner, boolean reflowLongStrings) throws IOException {
 			this.jarState = JarState.from(MAVEN_COORDINATE + version, provisioner);
 			this.stepName = stepName;
 			this.version = version;
 			this.style = style;
+			this.reflowLongStrings = reflowLongStrings;
 		}
 
 		@SuppressWarnings({"unchecked", "rawtypes"})
@@ -153,11 +173,14 @@ FormatterFunc createFormat() throws Exception {
 			Class<?> importOrdererClass = classLoader.loadClass(IMPORT_ORDERER_CLASS);
 			Method importOrdererMethod = importOrdererClass.getMethod(IMPORT_ORDERER_METHOD, String.class);
 
+			BiFunction<String, Object, String> reflowLongStrings = this.reflowLongStrings ? constructReflowLongStringsFunction(classLoader, formatterClazz) : (s, f) -> s;
+
 			return suggestJre11(input -> {
 				String formatted = (String) formatterMethod.invoke(formatter, input);
 				String removedUnused = removeUnused.apply(formatted);
 				String sortedImports = (String) importOrdererMethod.invoke(null, removedUnused);
-				return fixWindowsBug(sortedImports, version);
+				String reflowedLongStrings = reflowLongStrings.apply(sortedImports, formatter);
+				return fixWindowsBug(reflowedLongStrings, version);
 			});
 		}
 
@@ -191,6 +214,20 @@ private static Function<String, String> constructRemoveUnusedFunction(ClassLoade
 			}
 			return removeUnused;
 		}
+
+		private static BiFunction<String, Object, String> constructReflowLongStringsFunction(ClassLoader classLoader, Class<?> formatterClazz) throws NoSuchMethodException {
+			Class<?> stringWrapperClass;
+			try {
+				stringWrapperClass = classLoader.loadClass(STRING_WRAPPER_CLASS);
+			} catch (ClassNotFoundException e) {
+				// google-java-format 1.7 or lower, which happen to be LATEST_VERSION_JRE_8, so rely on suggestJre11 for the error
+				return (s, f) -> {
+					throw e;
+				};
+			}
+			Method stringWrapperMethod = stringWrapperClass.getMethod(STRING_WRAPPER_METHOD, String.class, formatterClazz);
+			return (s, f) -> (String) stringWrapperMethod.invoke(null, s, f);
+		}
 	}
 
 	private static final boolean IS_WINDOWS = LineEnding.PLATFORM_NATIVE.str().equals("\r\n");

plugin-gradle/CHANGES.md

@@ -3,6 +3,8 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `3.27.0`).
 
 ## [Unreleased]
+### Added
+* Added support for `google-java-format`'s `skip-reflowing-long-strings` option ([#929](https://github.com/diffplug/spotless/pull/929))
 
 ## [5.14.3] - 2021-08-20
 ### Changed

plugin-gradle/README.md

@@ -112,7 +112,7 @@ spotless {
     // don't need to set target, it is inferred from java
 
     // apply a specific flavor of google-java-format
-    googleJavaFormat('1.8').aosp()
+    googleJavaFormat('1.8').aosp().reflowLongStrings()
     // make sure every file has the following copyright header.
     // optionally, Spotless can set copyright years by digging
     // through git history (see "license" section below)
@@ -176,9 +176,9 @@ spotless {
 spotless {
   java {
     googleJavaFormat()
-    // optional: you can specify a specific version and/or switch to AOSP style
+    // optional: you can specify a specific version and/or switch to AOSP style and/or reflow long strings (requires at least 1.8)
     //
-    googleJavaFormat('1.7').aosp()
+    googleJavaFormat('1.8').aosp().reflowLongStrings()
 ```
 
 ### eclipse jdt

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

@@ -90,26 +90,39 @@ public GoogleJavaFormatConfig googleJavaFormat(String version) {
 	public class GoogleJavaFormatConfig {
 		final String version;
 		String style;
+		boolean reflowLongStrings;
 
 		GoogleJavaFormatConfig(String version) {
 			this.version = Objects.requireNonNull(version);
 			this.style = GoogleJavaFormatStep.defaultStyle();
 			addStep(createStep());
 		}
 
-		public void style(String style) {
+		public GoogleJavaFormatConfig style(String style) {
 			this.style = Objects.requireNonNull(style);
 			replaceStep(createStep());
+			return this;
 		}
 
-		public void aosp() {
-			style("AOSP");
+		public GoogleJavaFormatConfig aosp() {
+			return style("AOSP");
+		}
+
+		public GoogleJavaFormatConfig reflowLongStrings() {
+			return reflowLongStrings(true);
+		}
+
+		public GoogleJavaFormatConfig reflowLongStrings(boolean reflowLongStrings) {
+			this.reflowLongStrings = reflowLongStrings;
+			replaceStep(createStep());
+			return this;
 		}
 
 		private FormatterStep createStep() {
 			return GoogleJavaFormatStep.create(version,
 					style,
-					provisioner());
+					provisioner(),
+					reflowLongStrings);
 		}
 	}
 

plugin-maven/CHANGES.md

@@ -3,6 +3,8 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+### Added
+* Added support for `google-java-format`'s `skip-reflowing-long-strings` option ([#929](https://github.com/diffplug/spotless/pull/929))
 
 ## [2.12.3] - 2021-08-20
 ### Changed

plugin-maven/README.md

@@ -105,10 +105,11 @@ To use it in your pom, just [add the Spotless dependency](https://search.maven.o
     <java>
       <!-- no need to specify files, inferred automatically, but you can if you want -->
 
-      <!-- apply a specific flavor of google-java-format -->
+      <!-- apply a specific flavor of google-java-format and reflow long strings -->
       <googleJavaFormat>
         <version>1.8</version>
         <style>AOSP</style>
+        <reflowLongStrings>true</reflowLongStrings>
       </googleJavaFormat>
 
       <!-- make sure every file has the following copyright header.
@@ -201,8 +202,9 @@ any other maven phase (i.e. compile) then it can be configured as below;
 
 ```xml
 <googleJavaFormat>
-  <version>1.7</version> <!-- optional -->
-  <style>GOOGLE</style>  <!-- or AOSP (optional) -->
+  <version>1.8</version>                      <!-- optional -->
+  <style>GOOGLE</style>                       <!-- or AOSP (optional) -->
+  <reflowLongStrings>true</reflowLongStrings> <!-- optional (requires at least 1.8) -->
 </googleJavaFormat>
 ```
 

plugin-maven/src/main/java/com/diffplug/spotless/maven/java/GoogleJavaFormat.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.
@@ -29,10 +29,14 @@ public class GoogleJavaFormat implements FormatterStepFactory {
 	@Parameter
 	private String style;
 
+	@Parameter
+	private Boolean reflowLongStrings;
+
 	@Override
 	public FormatterStep newFormatterStep(FormatterStepConfig config) {
 		String version = this.version != null ? this.version : GoogleJavaFormatStep.defaultVersion();
 		String style = this.style != null ? this.style : GoogleJavaFormatStep.defaultStyle();
-		return GoogleJavaFormatStep.create(version, style, config.getProvisioner());
+		boolean reflowLongStrings = this.reflowLongStrings != null ? this.reflowLongStrings : GoogleJavaFormatStep.defaultReflowLongStrings();
+		return GoogleJavaFormatStep.create(version, style, config.getProvisioner(), reflowLongStrings);
 	}
 }

plugin-maven/src/test/java/com/diffplug/spotless/maven/java/GoogleJavaFormatTest.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.
@@ -17,6 +17,7 @@
 
 import org.junit.Test;
 
+import com.diffplug.spotless.JreVersion;
 import com.diffplug.spotless.maven.MavenIntegrationHarness;
 
 public class GoogleJavaFormatTest extends MavenIntegrationHarness {
@@ -41,6 +42,18 @@ public void specificVersionSpecificStyle() throws Exception {
 		runTest("java/googlejavaformat/JavaCodeFormattedAOSP.test");
 	}
 
+	@Test
+	public void specificVersionReflowLongStrings() throws Exception {
+		JreVersion.assume11OrGreater();
+		writePomWithJavaSteps(
+				"<googleJavaFormat>",
+				"  <version>1.8</version>",
+				"  <reflowLongStrings>true</reflowLongStrings>",
+				"</googleJavaFormat>");
+
+		runTest("java/googlejavaformat/JavaCodeFormattedReflowLongStrings.test");
+	}
+
 	private void runTest(String targetResource) throws Exception {
 		String path = "src/main/java/test.java";
 		setFile(path).toResource("java/googlejavaformat/JavaCodeUnformatted.test");

testlib/src/main/resources/java/googlejavaformat/JavaCodeFormatted.test

@@ -4,7 +4,8 @@ import mylib.UsedB;
 
 public class Java {
   public static void main(String[] args) {
-    System.out.println("hello");
+    System.out.println(
+        "A very very very very very very very very very very very very very very very very very very very very very long string that goes beyond the 100-character line length.");
     UsedB.someMethod();
     UsedA.someMethod();
   }