review: feature: CtElement#getRoleInParent()

src/main/java/spoon/reflect/declaration/CtElement.java

@@ -19,6 +19,7 @@
 import spoon.processing.FactoryAccessor;
 import spoon.reflect.code.CtComment;
 import spoon.reflect.cu.SourcePosition;
+import spoon.reflect.path.CtRole;
 import spoon.reflect.reference.CtTypeReference;
 import spoon.reflect.visitor.CtVisitable;
 import spoon.reflect.visitor.Filter;
@@ -255,6 +256,12 @@ <E extends CtElement> List<E> getAnnotatedChildren(
 	 */
 	void updateAllParentsBelow();
 
+	/**
+	 * @return the {@link CtRole} of the parent's attribute where this element is used.
+	 * Returns null if parent doesn't contain this element as direct children or if this element has no parent.
+	 */
+	CtRole getRoleInParent();
+
 	/*
 	 * Deletes the element. For instance, delete a statement from its containing block. Warning: it may result in an incorrect AST, use at your own risk.
 	 */

src/main/java/spoon/support/reflect/declaration/CtElementImpl.java

@@ -31,6 +31,7 @@
 import spoon.reflect.reference.CtTypeReference;
 import spoon.reflect.visitor.CtScanner;
 import spoon.reflect.visitor.DefaultJavaPrettyPrinter;
+import spoon.reflect.visitor.EarlyTerminatingScanner;
 import spoon.reflect.visitor.Filter;
 import spoon.reflect.visitor.ModelConsistencyChecker;
 import spoon.reflect.visitor.Query;
@@ -375,6 +376,25 @@ public boolean hasParent(CtElement candidate) {
 		}
 	}
 
+	@Override
+	public CtRole getRoleInParent() {
+		if (isParentInitialized()) {
+			EarlyTerminatingScanner<CtRole> ets = new EarlyTerminatingScanner<CtRole>() {
+				@Override
+				public void scan(CtRole role, CtElement element) {
+					if (element == CtElementImpl.this) {
+						setResult(role);
+						terminate();
+					}
+					//do not call super.scan, because we do not want scan children
+				}
+			};
+			getParent().accept(ets);
+			return ets.getResult();
+		}
+		return null;
+	}
+
 	@Override
 	public void updateAllParentsBelow() {
 		new ModelConsistencyChecker(getFactory().getEnvironment(), true, true).scan(this);

src/test/java/spoon/test/main/MainTest.java

@@ -1,6 +1,7 @@
 package spoon.test.main;
 
 import org.junit.Assert;
+import org.junit.BeforeClass;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.contrib.java.lang.system.Assertion;
@@ -22,6 +23,7 @@
 import spoon.reflect.declaration.CtType;
 import spoon.reflect.declaration.CtTypeParameter;
 import spoon.reflect.declaration.ParentNotInitializedException;
+import spoon.reflect.path.CtRole;
 import spoon.reflect.reference.CtArrayTypeReference;
 import spoon.reflect.reference.CtExecutableReference;
 import spoon.reflect.reference.CtFieldReference;
@@ -48,13 +50,19 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 
 public class MainTest {
-
-	@Test
-	public void testMain() throws Exception {
-
+
+	static Launcher launcher;
+	static CtPackage rootPackage;
+
+	/**
+	 * load model once into static variable and use it for more read-only tests
+	 */
+	@BeforeClass
+	public static void loadModel() {
 		// we have to remove the test-classes folder
 		// so that the precondition of --source-classpath is not violated
 		// (target/test-classes contains src/test/resources which itself contains Java files)
@@ -67,7 +75,7 @@ public void testMain() throws Exception {
 		}
 		String systemClassPath = classpath.substring(0, classpath.length() - 1);
 
-		Launcher launcher = new Launcher();
+		launcher = new Launcher();
 
 		launcher.run(new String[] {
 				"-i", "src/main/java",
@@ -78,14 +86,23 @@ public void testMain() throws Exception {
 				"--compliance", "8",
 				"--level", "OFF"
 		});
+
+		rootPackage = launcher.getFactory().Package().getRootPackage();
+	}
+
+	@Test
+	public void testMain_checkGenericContracts() {
+		checkGenericContracts(rootPackage);
+	}
+
+	@Test
+	public void testMain_checkShadow() {
+		checkShadow(rootPackage);
+	}
 
-		checkGenericContracts(launcher.getFactory().Package().getRootPackage());
-
-		checkShadow(launcher.getFactory().Package().getRootPackage());
-
-		checkParentConsistency(launcher.getFactory().Package().getRootPackage());
-
-		checkModelIsTree(launcher.getFactory().Package().getRootPackage());
+	@Test
+	public void testMain_checkParentConsistency() {
+		checkParentConsistency(rootPackage);
 	}
 
 	public void checkGenericContracts(CtPackage pack) {
@@ -347,13 +364,12 @@ protected void exit(CtElement e) {
 		assertEquals("All parents have to be consistent", 0, inconsistentParents.size());
 	}
 
-
-
 	/*
 	 * contract: each element is used only once
 	 * For example this is always true: field.getType() != field.getDeclaringType()
 	 */
-	private void checkModelIsTree(CtPackage rootPackage) {
+	@Test
+	public void checkModelIsTree() {
 		Exception dummyException = new Exception("STACK");
 		PrinterHelper problems = new PrinterHelper(rootPackage.getFactory().getEnvironment());
 		Map<CtElement, Exception> allElements = new IdentityHashMap<>();
@@ -390,7 +406,19 @@ private String getStackTrace(Exception e) {
 		return sw.toString();
 	}
 
-
+	@Test
+	public void testMyRoleInParent() {
+		rootPackage.accept(new CtScanner() {
+			@Override
+			public void scan(CtRole role, CtElement element) {
+				if (element != null) {
+					//contract: getMyRoleInParent returns the expected parent
+					assertSame(role, element.getRoleInParent());
+				}
+				super.scan(role, element);
+			}
+		});
+	}
 
 	@Test
 	public void testTest() throws Exception {