Fix classLoader issue

Author: blacelle

lib/src/cleanthat/java/com/diffplug/spotless/glue/java/JavaCleanthatRefactorerFunc.java

@@ -15,6 +15,7 @@
  */
 package com.diffplug.spotless.glue.java;
 
+import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
@@ -25,6 +26,7 @@
 import com.diffplug.spotless.FormatterFunc;
 
 import eu.solven.cleanthat.config.pojo.CleanthatEngineProperties;
+import eu.solven.cleanthat.config.pojo.SourceCodeProperties;
 import eu.solven.cleanthat.engine.java.IJdkVersionConstants;
 import eu.solven.cleanthat.engine.java.refactorer.JavaRefactorer;
 import eu.solven.cleanthat.engine.java.refactorer.JavaRefactorerProperties;
@@ -53,8 +55,25 @@ public JavaCleanthatRefactorerFunc() {
 
 	@Override
 	public String apply(String input) throws Exception {
+		// https://stackoverflow.com/questions/1771679/difference-between-threads-context-class-loader-and-normal-classloader
+		ClassLoader originalClassLoader = Thread.currentThread().getContextClassLoader();
+		try {
+			// Ensure CleanThat main Thread has its custom classLoader while executing its refactoring
+			Thread.currentThread().setContextClassLoader(getClass().getClassLoader());
+			return doApply(input);
+		} finally {
+			// Restore the originalClassLoader
+			Thread.currentThread().setContextClassLoader(originalClassLoader);
+		}
+	}
+
+	private String doApply(String input) throws InterruptedException, IOException {
+		// call some API that uses reflection without taking ClassLoader param
 		CleanthatEngineProperties engineProperties = CleanthatEngineProperties.builder().engineVersion(jdkVersion).build();
 
+		// Spotless will push us LF content
+		engineProperties.setSourceCode(SourceCodeProperties.builder().lineEnding(LineEnding.LF).build());
+
 		JavaRefactorerProperties refactorerProperties = new JavaRefactorerProperties();
 
 		refactorerProperties.setIncluded(included);

plugin-maven/src/test/java/com/diffplug/spotless/maven/java/CleanthatJavaRefactorerTest.java

@@ -35,11 +35,21 @@ void testLiteralsFirstInComparisons() throws Exception {
 	}
 
 	@Test
-	void testMultipleMutators() throws Exception {
+	void testMultipleMutators_defaultIsJdk7() throws Exception {
 		writePomWithJavaSteps(
 				"<cleanthat>",
 				"</cleanthat>");
 
+		runTest("MultipleMutators.dirty.java", "MultipleMutators.clean.onlyLiteralsFirst.java");
+	}
+
+	@Test
+	void testMultipleMutators_Jdk11IntroducedOptionalisPresent() throws Exception {
+		writePomWithJavaSteps(
+				"<cleanthat>",
+				"<sourceJdk>11</sourceJdk>",
+				"</cleanthat>");
+
 		runTest("MultipleMutators.dirty.java", "MultipleMutators.clean.java");
 	}
 
@@ -70,7 +80,8 @@ void testIncludeOnlyLiteralsFirstInComparisons() throws Exception {
 	private void runTest(String dirtyPath, String cleanPath) throws Exception {
 		String path = "src/main/java/test.java";
 		setFile(path).toResource("java/cleanthat/" + dirtyPath);
-		Assertions.assertThat(mavenRunner().withArguments("spotless:apply").withRemoteDebug(21654).runNoError().stdOutUtf8()).doesNotContain("[ERROR]");
+		// .withRemoteDebug(21654)
+		Assertions.assertThat(mavenRunner().withArguments("spotless:apply").runNoError().stdOutUtf8()).doesNotContain("[ERROR]");
 		assertFile(path).sameAsResource("java/cleanthat/" + cleanPath);
 	}
 }

testlib/src/main/resources/java/cleanthat/MultipleMutators.clean.java

@@ -5,7 +5,7 @@
 public class LiteralsFirstInComparisonsCases {
 
 	public boolean isHardcoded(String input) {
-		return input.equals("hardcoded");
+		return "hardcoded".equals(input);
 	}
 
 	public boolean isPresent(Optional<?> optional) {