fix(test): CtGenerationTest#testGenerateRoleHandler egg/chicken problem

src/main/java/spoon/metamodel/Metamodel.java

@@ -209,6 +209,16 @@ public static Set<CtType<?>> getAllMetamodelInterfaces() {
 	 */
 	public static Metamodel getInstance() {
 		if (instance == null) {
+			try {
+				//this is needed just for CtGenerationTest#testGenerateRoleHandler
+				//which must not use RoleHandler at time when RoleHandler is generated and Spoon model doesn't fit to old RoleHandlers
+				//to avoid egg/chicken problem
+				if ("true".equals(System.getProperty(MetamodelProperty.class.getName() + "-noRoleHandler"))) {
+					MetamodelProperty.useRuntimeMethodInvocation = true;
+				}
+			} catch (SecurityException e) {
+				//ignore that
+			}
 			instance = new Metamodel();
 		}
 		return instance;

src/main/java/spoon/metamodel/MetamodelProperty.java

@@ -19,6 +19,8 @@
 import static spoon.metamodel.Metamodel.addUniqueObject;
 import static spoon.metamodel.Metamodel.getOrCreate;
 
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -39,6 +41,7 @@
 import spoon.reflect.reference.CtTypeReference;
 import spoon.support.DerivedProperty;
 import spoon.support.UnsettableProperty;
+import spoon.support.util.RtHelper;
 
 /**
  * Represents a property of the Spoon metamodel.
@@ -587,11 +590,27 @@ public RoleHandler getRoleHandler() {
 		return roleHandler;
 	}
 
+	static boolean useRuntimeMethodInvocation = false;
+
 	/**
 	 * @param element an instance whose attribute value is read
 	 * @return a value of attribute defined by this {@link MetamodelProperty} from the provided `element`
 	 */
 	public <T, U> U getValue(T element) {
+		if (useRuntimeMethodInvocation) {
+			MMMethod method = getMethod(MMMethodKind.GET);
+			if (method != null) {
+				Method rtMethod = RtHelper.getMethod(getOwner().getImplementationClass().getActualClass(), method.getName(), 0);
+				if (rtMethod != null) {
+					try {
+						return (U) rtMethod.invoke(element);
+					} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+						throw new SpoonException("Invokation of getter on " + toString() + " failed", e);
+					}
+				}
+				throw new SpoonException("Cannot invoke getter on " + toString());
+			}
+		}
 		return getRoleHandler().getValue(element);
 	}
 
@@ -600,6 +619,21 @@ public <T, U> U getValue(T element) {
 	 * @param value to be set value of attribute defined by this {@link MetamodelProperty} on the provided `element`
 	 */
 	public <T, U> void setValue(T element, U value) {
+		if (useRuntimeMethodInvocation) {
+			MMMethod method = getMethod(MMMethodKind.SET);
+			if (method != null) {
+				Method rtMethod = RtHelper.getMethod(getOwner().getImplementationClass().getActualClass(), method.getName(), 1);
+				if (rtMethod != null) {
+					try {
+						rtMethod.invoke(element, value);
+					} catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e) {
+						throw new SpoonException("Invokation of setter on " + toString() + " failed", e);
+					}
+					return;
+				}
+				throw new SpoonException("Cannot invoke setter on " + toString());
+			}
+		}
 		getRoleHandler().setValue(element, value);
 	}
 }

src/test/java/spoon/processing/CtGenerationTest.java

@@ -7,6 +7,7 @@
 import spoon.generating.CtBiScannerGenerator;
 import spoon.generating.ReplacementVisitorGenerator;
 import spoon.generating.RoleHandlersGenerator;
+import spoon.metamodel.MetamodelProperty;
 import spoon.reflect.declaration.CtClass;
 import spoon.reflect.declaration.CtType;
 import spoon.reflect.visitor.CtBiScannerDefault;
@@ -173,7 +174,12 @@ public void testGenerateRoleHandler() throws Exception {
 		launcher.addInputResource("./src/main/java/spoon/reflect/meta/impl/AbstractRoleHandler.java");
 		launcher.addProcessor(new RoleHandlersGenerator());
 		launcher.setOutputFilter(new RegexFilter("\\Q" + RoleHandlersGenerator.TARGET_PACKAGE + ".ModelRoleHandlers\\E.*"));
-		launcher.run();
+		try {
+			System.setProperty(MetamodelProperty.class.getName()+"-noRoleHandler", "true");
+			launcher.run();
+		} finally {
+			System.setProperty(MetamodelProperty.class.getName()+"-noRoleHandler", "false");
+		}
 
 		// cp ./target/generated/spoon/reflect/meta/impl/ModelRoleHandlers.java ./src/main/java/spoon/reflect/meta/impl/ModelRoleHandlers.java
 		CtClass<Object> actual = build(new File(launcher.getModelBuilder().getSourceOutputDirectory()+"/spoon/reflect/meta/impl/ModelRoleHandlers.java")).Class().get("spoon.reflect.meta.impl.ModelRoleHandlers");