RuleTemporayFolderJUnitPlugin.java

/*******************************************************************************
 * Copyright (c) 2021 Carsten Hammer.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     Carsten Hammer
 *******************************************************************************/
package org.sandbox.jdt.internal.corext.fix.helper;

import static org.sandbox.jdt.internal.corext.fix.helper.lib.JUnitConstants.*;

import org.eclipse.jdt.core.dom.AST;
import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.FieldDeclaration;
import org.eclipse.jdt.core.dom.ITypeBinding;
import org.eclipse.jdt.core.dom.MarkerAnnotation;
import org.eclipse.jdt.core.dom.MethodDeclaration;
import org.eclipse.jdt.core.dom.MethodInvocation;
import org.eclipse.jdt.core.dom.TypeDeclaration;
import org.eclipse.jdt.core.dom.VariableDeclarationFragment;
import org.eclipse.jdt.core.dom.rewrite.ASTRewrite;
import org.eclipse.jdt.core.dom.rewrite.ImportRewrite;
import org.eclipse.jdt.internal.corext.dom.ASTNodes;
import org.eclipse.text.edits.TextEditGroup;
import org.sandbox.jdt.internal.corext.util.AnnotationUtils;
import org.sandbox.jdt.internal.common.AstProcessorBuilder;
import org.sandbox.jdt.internal.common.ReferenceHolder;
import org.sandbox.jdt.internal.corext.fix.helper.lib.JunitHolder;
import org.sandbox.jdt.internal.corext.fix.helper.lib.TriggerPatternCleanupPlugin;
import org.sandbox.jdt.internal.corext.fix.helper.lib.TestNameRefactorer;
import org.sandbox.jdt.triggerpattern.api.CleanupPattern;
import org.sandbox.jdt.triggerpattern.api.Match;
import org.sandbox.jdt.triggerpattern.api.PatternKind;

/**
 * Plugin to migrate JUnit 4 TemporaryFolder rule to JUnit 5 @TempDir.
 *
 * @since 1.3.0
 */
@CleanupPattern(value = "@Rule public TemporaryFolder $name", kind = PatternKind.FIELD, qualifiedType = ORG_JUNIT_RULES_TEMPORARY_FOLDER, cleanupId = "cleanup.junit.ruletemporaryfolder", description = "Migrate @Rule TemporaryFolder to @TempDir", displayName = "JUnit 4 @Rule TemporaryFolder \u2192 JUnit 5 @TempDir")
public class RuleTemporayFolderJUnitPlugin extends TriggerPatternCleanupPlugin {

	@Override
	protected JunitHolder createHolder(Match match) {
		FieldDeclaration fieldDecl = (FieldDeclaration) match.getMatchedNode();
		VariableDeclarationFragment fragment = (VariableDeclarationFragment) fieldDecl.fragments().get(0);
		if (fragment.resolveBinding() == null) {
			return null;
		}
		ITypeBinding binding = fragment.resolveBinding().getType();
		if (binding == null || !ORG_JUNIT_RULES_TEMPORARY_FOLDER.equals(binding.getQualifiedName())) {
			return null;
		}
		JunitHolder holder = new JunitHolder();
		holder.setMinv(fieldDecl);
		return holder;
	}

	@Override
	protected void process2Rewrite(TextEditGroup group, ASTRewrite rewriter, AST ast, ImportRewrite importRewriter,
			JunitHolder junitHolder) {
		FieldDeclaration field = junitHolder.getFieldDeclaration();
		rewriter.remove(field, group);
		TypeDeclaration parentClass = ASTNodes.getParent(field, TypeDeclaration.class);

		VariableDeclarationFragment originalFragment = (VariableDeclarationFragment) field.fragments().get(0);
		String originalName = originalFragment.getName().getIdentifier();

		// Add JUnit 5 imports and remove JUnit 4 imports
		importRewriter.addImport(ORG_JUNIT_JUPITER_API_IO_TEMP_DIR);
		importRewriter.addImport("java.nio.file.Path");
		importRewriter.removeImport(ORG_JUNIT_RULE);
		importRewriter.removeImport(ORG_JUNIT_RULES_TEMPORARY_FOLDER);

		// Create new field: @TempDir Path fieldName;
		VariableDeclarationFragment tempDirFragment = ast.newVariableDeclarationFragment();
		tempDirFragment.setName(ast.newSimpleName(originalName));

		FieldDeclaration tempDirField = ast.newFieldDeclaration(tempDirFragment);
		tempDirField.setType(ast.newSimpleType(ast.newName("Path")));

		MarkerAnnotation tempDirAnnotation = AnnotationUtils.createMarkerAnnotation(ast, "TempDir");
		rewriter.getListRewrite(tempDirField, FieldDeclaration.MODIFIERS2_PROPERTY).insertFirst(tempDirAnnotation,
				group);

		rewriter.getListRewrite(parentClass, TypeDeclaration.BODY_DECLARATIONS_PROPERTY).insertFirst(tempDirField,
				group);

		// Transform method invocations in a single pass (also determines if Files
		// import is needed)
		final boolean[] needsFilesImport = { false };
		for (MethodDeclaration method : parentClass.getMethods()) {
			ReferenceHolder<String, Object> visitHolder = ReferenceHolder.create();
			AstProcessorBuilder.with(visitHolder)
				.onMethodInvocation((node, h) -> {
					if (node.getExpression() == null) {
						return true;
					}

					String expressionName = node.getExpression().toString();
					if (!originalName.equals(expressionName)) {
						return true;
					}

					String methodName = node.getName().getIdentifier();

					// Handle newFile() and newFile(String)
					if ("newFile".equals(methodName)) {
						needsFilesImport[0] = true;
						if (node.arguments().isEmpty()) {
							// newFile() with no args -> Files.createTempFile(tempDir, "", null).toFile()
							MethodInvocation createTempFileInvocation = ast.newMethodInvocation();
							createTempFileInvocation.setExpression(ast.newName("Files"));
							createTempFileInvocation.setName(ast.newSimpleName("createTempFile"));
							createTempFileInvocation.arguments().add(ast.newSimpleName(originalName));
							createTempFileInvocation.arguments().add(ast.newStringLiteral());
							createTempFileInvocation.arguments().add(ast.newNullLiteral());

							MethodInvocation toFileInvocation = ast.newMethodInvocation();
							toFileInvocation.setExpression(createTempFileInvocation);
							toFileInvocation.setName(ast.newSimpleName("toFile"));

							rewriter.replace(node, toFileInvocation, group);
						} else {
							// newFile(String) -> Files.createFile(tempDir.resolve(...)).toFile()
							MethodInvocation createFileInvocation = ast.newMethodInvocation();
							createFileInvocation.setExpression(ast.newName("Files"));
							createFileInvocation.setName(ast.newSimpleName("createFile"));

							MethodInvocation resolveInvocation = ast.newMethodInvocation();
							resolveInvocation.setExpression(ast.newSimpleName(originalName));
							resolveInvocation.setName(ast.newSimpleName("resolve"));
							// newFile only takes a single String argument
							// Copy and transform TestName.getMethodName() calls in the argument
							ASTNode originalArg = (ASTNode) node.arguments().get(0);
							resolveInvocation.arguments()
									.add(TestNameRefactorer.copyAndTransformTestNameReferences(originalArg, ast));

							createFileInvocation.arguments().add(resolveInvocation);

							MethodInvocation toFileInvocation = ast.newMethodInvocation();
							toFileInvocation.setExpression(createFileInvocation);
							toFileInvocation.setName(ast.newSimpleName("toFile"));

							rewriter.replace(node, toFileInvocation, group);
						}
					}
					// Handle newFolder() and newFolder(String...)
					else if ("newFolder".equals(methodName)) {
						needsFilesImport[0] = true;
						if (node.arguments().isEmpty()) {
							// newFolder() with no args -> Files.createTempDirectory(tempDir, "").toFile()
							MethodInvocation createTempDirInvocation = ast.newMethodInvocation();
							createTempDirInvocation.setExpression(ast.newName("Files"));
							createTempDirInvocation.setName(ast.newSimpleName("createTempDirectory"));
							createTempDirInvocation.arguments().add(ast.newSimpleName(originalName));
							createTempDirInvocation.arguments().add(ast.newStringLiteral());

							MethodInvocation toFileInvocation = ast.newMethodInvocation();
							toFileInvocation.setExpression(createTempDirInvocation);
							toFileInvocation.setName(ast.newSimpleName("toFile"));

							rewriter.replace(node, toFileInvocation, group);
						} else {
							// newFolder(String...) ->
							// Files.createDirectories(tempDir.resolve(...).resolve(...)).toFile()
							// For multiple arguments, chain resolve() calls
							MethodInvocation createDirInvocation = ast.newMethodInvocation();
							createDirInvocation.setExpression(ast.newName("Files"));
							createDirInvocation.setName(ast.newSimpleName("createDirectories"));

							// Build chained resolve() calls for multiple arguments
							// Start with tempFolder.resolve("a")
							ASTNode firstArg = (ASTNode) node.arguments().get(0);
							MethodInvocation chainedResolve = ast.newMethodInvocation();
							chainedResolve.setExpression(ast.newSimpleName(originalName));
							chainedResolve.setName(ast.newSimpleName("resolve"));
							chainedResolve.arguments()
									.add(TestNameRefactorer.copyAndTransformTestNameReferences(firstArg, ast));

							// Chain additional resolve() calls for subsequent arguments
							// .resolve("b").resolve("c")...
							for (int i = 1; i < node.arguments().size(); i++) {
								ASTNode arg = (ASTNode) node.arguments().get(i);
								MethodInvocation nextResolve = ast.newMethodInvocation();
								nextResolve.setExpression(chainedResolve);
								nextResolve.setName(ast.newSimpleName("resolve"));
								nextResolve.arguments()
										.add(TestNameRefactorer.copyAndTransformTestNameReferences(arg, ast));
								chainedResolve = nextResolve;
							}

							createDirInvocation.arguments().add(chainedResolve);

							MethodInvocation toFileInvocation = ast.newMethodInvocation();
							toFileInvocation.setExpression(createDirInvocation);
							toFileInvocation.setName(ast.newSimpleName("toFile"));

							rewriter.replace(node, toFileInvocation, group);
						}
					}
					// Handle getRoot()
					else if ("getRoot".equals(methodName)) {
						// tempDir.toFile()
						MethodInvocation toFileInvocation = ast.newMethodInvocation();
						toFileInvocation.setExpression(ast.newSimpleName(originalName));
						toFileInvocation.setName(ast.newSimpleName("toFile"));

						rewriter.replace(node, toFileInvocation, group);
					}

					return true;
				})
				.build(method);
		}

		// Add Files import only if needed (determined during transformation)
		if (needsFilesImport[0]) {
			importRewriter.addImport("java.nio.file.Files");
		}
	}

	@Override
	public String getPreview(boolean afterRefactoring) {
		if (afterRefactoring) {
			return """
						@TempDir
						Path tempFolder;

						@Test
						public void test3() throws IOException{
							File newFile = Files.createFile(tempFolder.resolve("myfile.txt")).toFile();
						}
					"""; //$NON-NLS-1$
		}
		return """
					@Rule
					public TemporaryFolder tempFolder = new TemporaryFolder();

					@Test
					public void test3() throws IOException{
						File newFile = tempFolder.newFile("myfile.txt");
					}
				"""; //$NON-NLS-1$
	}

	@Override
	public String toString() {
		return "RuleTemporaryFolder"; //$NON-NLS-1$
	}
}