feat: port clang-format to maven plugin (#2406)

Author: nedtwigg

CHANGES.md

@@ -10,6 +10,7 @@ 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]
+* Support for`clang-format` on maven-plugin ([#2406](https://github.com/diffplug/spotless/pull/2406))
 
 ## [3.0.2] - 2025-01-14
 ### Fixed

plugin-maven/CHANGES.md

@@ -3,6 +3,7 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
+* Support for `clang-format` ([#2406](https://github.com/diffplug/spotless/pull/2406))
 
 ## [2.44.2] - 2025-01-14
 * Eclipse-based tasks can now handle parallel configuration ([#2389](https://github.com/diffplug/spotless/issues/2389))

plugin-maven/README.md

@@ -43,7 +43,7 @@ user@machine repo % mvn spotless:check
   - [Groovy](#groovy) ([eclipse groovy](#eclipse-groovy))
   - [Kotlin](#kotlin) ([ktfmt](#ktfmt), [ktlint](#ktlint), [diktat](#diktat), [prettier](#prettier))
   - [Scala](#scala) ([scalafmt](#scalafmt))
-  - [C/C++](#cc) ([eclipse cdt](#eclipse-cdt))
+  - [C/C++](#cc) ([eclipse cdt](#eclipse-cdt), [clang-format](#clang-format))
   - [Python](#python) ([black](#black))
   - [Antlr4](#antlr4) ([antlr4formatter](#antlr4formatter))
   - [Sql](#sql) ([dbeaver](#dbeaver))
@@ -56,7 +56,7 @@ user@machine repo % mvn spotless:check
   - [Gherkin](#gherkin)
   - [Go](#go)
   - [RDF](#RDF)
-  - [Protobuf](#protobuf) ([buf](#buf))
+  - [Protobuf](#protobuf) ([buf](#buf), [clang-format](#clang))
   - Multiple languages
     - [Prettier](#prettier) ([plugins](#prettier-plugins), [npm detection](#npm-detection), [`.npmrc` detection](#npmrc-detection), [caching `npm install` results](#caching-results-of-npm-install))
     - [eclipse web tools platform](#eclipse-web-tools-platform)
@@ -558,6 +558,18 @@ Additionally, `editorConfigOverride` options will override what's supplied in `.
 </eclipseCdt>
 ```
 
+### clang-format
+
+[homepage](https://clang.llvm.org/docs/ClangFormat.html). [changelog](https://releases.llvm.org/download.html). `clang-format` is a formatter for c, c++, c#, objective-c, protobuf, javascript, and java. You can use clang-format in any language-specific format, but usually you will be creating a generic format.
+
+```xml
+<clangFormat>
+  <version>14.0.0-1ubuntu1.1</version> <!-- optional version of clang-format -->
+  <pathToExe>/path/to/buf</pathToExe>  <!-- optional: if clang-format isn't in your path -->
+  <style>LLVM</style>  <!-- optional: can be LLVM, Google, Chromium, Mozilla, WebKit -->
+</clangFormat>
+```
+
 ## Python
 
 [code](https://github.com/diffplug/spotless/blob/main/plugin-maven/src/main/java/com/diffplug/spotless/maven/python/Python.java). [available steps](https://github.com/diffplug/spotless/tree/main/plugin-maven/src/main/java/com/diffplug/spotless/maven/python/Black.java).
@@ -1218,17 +1230,17 @@ RDF parsing is done via [Apache Jena](https://jena.apache.org/) in the version t
 [code](https://github.com/diffplug/spotless/blob/main/plugin-maven/src/main/java/com/diffplug/spotless/maven/protobuf/Protobuf.java). [available steps](https://github.com/diffplug/spotless/tree/main/plugin-maven/src/main/java/com/diffplug/spotless/maven/protobuf).
 ```xml
 <configuration>
-  <includes>  <!-- optiona: default is **/*.proto -->
-    <include>proto/*.proto<include>
-  <includes>
+  <includes>  <!-- optional: default is **/*.proto -->
+    <include>proto/*.proto</include>
+  </includes>
 
-  <excludes>  <!-- optiona: if you want to ignore auto generated protos -->
-    <include>target/**/<include>
-  <excludes>
+  <excludes>  <!-- optional: if you want to ignore auto generated protos -->
+    <exclude>target/**/<exclude>
+  </excludes>
 
   <protobuf>
     <buf />  <!-- has its own section below -->
-  </css>
+  </protobuf>
 </configuration>
 ```
 

plugin-maven/src/main/java/com/diffplug/spotless/maven/cpp/Clang.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2024-2025 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.maven.cpp;
+
+import org.apache.maven.plugins.annotations.Parameter;
+
+import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.cpp.ClangFormatStep;
+import com.diffplug.spotless.maven.FormatterStepConfig;
+import com.diffplug.spotless.maven.FormatterStepFactory;
+
+public class Clang implements FormatterStepFactory {
+	@Parameter
+	private String version;
+
+	@Parameter
+	private String pathToExe;
+
+	@Parameter
+	private String style;
+
+	@Override
+	public FormatterStep newFormatterStep(FormatterStepConfig config) {
+		ClangFormatStep clang = ClangFormatStep.withVersion(version == null ? ClangFormatStep.defaultVersion() : version);
+
+		if (pathToExe != null) {
+			clang = clang.withPathToExe(pathToExe);
+		}
+
+		if (style != null) {
+			clang = clang.withStyle(style);
+		}
+
+		return clang.create();
+	}
+
+}

plugin-maven/src/main/java/com/diffplug/spotless/maven/cpp/Cpp.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.
@@ -40,6 +40,10 @@ public void addEclipseCdt(EclipseCdt eclipse) {
 		addStepFactory(eclipse);
 	}
 
+	public void addClangFormat(Clang clang) {
+		addStepFactory(clang);
+	}
+
 	@Override
 	public String licenseHeaderDelimiter() {
 		return CppDefaults.DELIMITER_EXPR;

plugin-maven/src/main/java/com/diffplug/spotless/maven/protobuf/Protobuf.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.
@@ -23,6 +23,7 @@
 
 import com.diffplug.common.collect.ImmutableSet;
 import com.diffplug.spotless.maven.FormatterFactory;
+import com.diffplug.spotless.maven.cpp.Clang;
 import com.diffplug.spotless.maven.generic.LicenseHeader;
 
 /**
@@ -49,4 +50,8 @@ public String licenseHeaderDelimiter() {
 	public void addBuf(Buf buf) {
 		addStepFactory(buf);
 	}
+
+	public void addClang(Clang clang) {
+		addStepFactory(clang);
+	}
 }

plugin-maven/src/test/java/com/diffplug/spotless/maven/cpp/ClangMavenIntegrationTest.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2024-2025 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.maven.cpp;
+
+import org.junit.jupiter.api.Test;
+
+import com.diffplug.spotless.maven.MavenIntegrationHarness;
+import com.diffplug.spotless.tag.ClangTest;
+
+@ClangTest
+class ClangMavenIntegrationTest extends MavenIntegrationHarness {
+
+	@Test
+	@ClangTest
+	void csharp() throws Exception {
+		writePomWithCppSteps("<includes>", "<include>", "src/**/*.cs", "</include>", "</includes>",
+				"<clangFormat>", "<version>", "14.0.0-1ubuntu1.1", "</version>", "</clangFormat>");
+		setFile("src/test.cs").toResource("clang/example.cs");
+		mavenRunner().withArguments("spotless:apply").runNoError();
+		assertFile("src/test.cs").sameAsResource("clang/example.cs.clean");
+	}
+
+	@Test
+	@ClangTest
+	void proto() throws Exception {
+		writePomWithCppSteps("<includes>", "<include>", "**/*.proto", "</include>", "</includes>",
+				"<clangFormat>", "<version>", "14.0.0-1ubuntu1.1", "</version>", "</clangFormat>");
+		setFile("buf.proto").toResource("protobuf/buf/buf.proto");
+		mavenRunner().withArguments("spotless:apply").runNoError();
+		assertFile("buf.proto").sameAsResource("protobuf/buf/buf.proto.clean");
+	}
+
+}