Added support for custom JSR-223 based formatters

Author: tisoft

README.md

@@ -46,6 +46,7 @@ output = [
 '| Fast format on fresh checkout using buildcache | {{yes}}      | {{no}}       | {{no}}       | {{no}}  |',
 lib('generic.EndWithNewlineStep')                +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
 lib('generic.IndentStep')                        +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
+lib('generic.JSR223Step')                        +'{{no}}        | {{yes}}      | {{no}}       | {{no}}  |',
 lib('generic.LicenseHeaderStep')                 +'{{yes}}       | {{yes}}      | {{yes}}      | {{no}}  |',
 lib('generic.ReplaceRegexStep')                  +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',
 lib('generic.ReplaceStep')                       +'{{yes}}       | {{yes}}      | {{no}}       | {{no}}  |',

lib/src/main/java/com/diffplug/spotless/generic/Jsr223Step.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2021 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.generic;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+
+import com.diffplug.spotless.FormatterFunc;
+import com.diffplug.spotless.FormatterStep;
+
+public final class Jsr223Step {
+	// prevent direct instantiation
+	private Jsr223Step() {}
+
+	public static FormatterStep create(String name, CharSequence engine, CharSequence script) {
+		Objects.requireNonNull(name, "name");
+		Objects.requireNonNull(engine, "engine");
+		Objects.requireNonNull(script, "script");
+		return FormatterStep.createLazy(name,
+				() -> new State(engine, script),
+				State::toFormatter);
+	}
+
+	private static final class State implements Serializable {
+		private static final long serialVersionUID = 1L;
+
+		private final String engine;
+		private final String script;
+
+		State(CharSequence engine, CharSequence script) {
+			this.engine = engine.toString();
+			this.script = script.toString();
+		}
+
+		FormatterFunc toFormatter() {
+			ScriptEngineManager scriptEngineManager = new ScriptEngineManager();
+			ScriptEngine scriptEngine = scriptEngineManager.getEngineByName(engine);
+
+			// evaluate JavaScript code
+			return raw -> {
+				scriptEngine.put("source", raw);
+				return (String) scriptEngine.eval(script);
+			};
+		}
+	}
+}

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 custom JSR223 formatters ([#945](https://github.com/diffplug/spotless/pull/945))
 
 ## [2.13.0] - 2021-09-04
 ### Added

plugin-maven/README.md

@@ -767,6 +767,12 @@ to true.
   <spacesPerTab>4</spacesPerTab> <!-- optional, default is 4 -->
 </indent>
 
+<jsr223> <!-- specify replacements using JSR223 scripting -->
+  <name>Greetings to Mars</name>
+  <engine>nashorn</engine>
+  <script>source.replace('World','Mars');</script>
+</jsr223>
+
 <replace> <!-- specify replacements using search and replace -->
   <name>Say Hello to Mars</name>
   <search>World</search>

plugin-maven/src/main/java/com/diffplug/spotless/maven/FormatterFactory.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.
@@ -110,6 +110,10 @@ public final void addIndent(Indent indent) {
 		addStepFactory(indent);
 	}
 
+	public final void addJsr223(Jsr223 jsr223) {
+		addStepFactory(jsr223);
+	}
+
 	public final void addTrimTrailingWhitespace(TrimTrailingWhitespace trimTrailingWhitespace) {
 		addStepFactory(trimTrailingWhitespace);
 	}

plugin-maven/src/main/java/com/diffplug/spotless/maven/generic/Jsr223.java

@@ -0,0 +1,44 @@
+/*
+ * Copyright 2021 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.generic;
+
+import org.apache.maven.plugins.annotations.Parameter;
+
+import com.diffplug.spotless.FormatterStep;
+import com.diffplug.spotless.generic.Jsr223Step;
+import com.diffplug.spotless.maven.FormatterStepConfig;
+import com.diffplug.spotless.maven.FormatterStepFactory;
+
+public class Jsr223 implements FormatterStepFactory {
+
+	@Parameter
+	private String name;
+
+	@Parameter
+	private String engine;
+
+	@Parameter
+	private String script;
+
+	@Override
+	public FormatterStep newFormatterStep(FormatterStepConfig config) {
+		if (name == null || engine == null || script == null) {
+			throw new IllegalArgumentException("Must specify 'name', 'engine' and 'script'.");
+		}
+
+		return Jsr223Step.create(name, engine, script);
+	}
+}

plugin-maven/src/test/java/com/diffplug/spotless/maven/generic/Jsr223Test.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2021 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.generic;
+
+import org.junit.Test;
+
+import com.diffplug.spotless.maven.MavenIntegrationHarness;
+
+public class Jsr223Test extends MavenIntegrationHarness {
+
+	@Test
+	public void fromContent() throws Exception {
+		writePomWithFormatSteps(
+				"<jsr223>",
+				"  <name>Greetings to Mars</name>",
+				"  <engine>nashorn</engine>",
+				"  <script>source.replace('World','Mars');</script>",
+				"</jsr223>");
+		runTest("Hello World", "Hello Mars");
+	}
+
+	private void runTest(String sourceContent, String targetContent) throws Exception {
+		String path = "src/main/java/test.java";
+		setFile(path).toContent(sourceContent);
+		mavenRunner().withArguments("spotless:apply").runNoError();
+		assertFile(path).hasContent(targetContent);
+	}
+}