feature: add filtering helpers (CatchVariableReferenceFunction, Catch…

…VariableScopeFunction) (#1145)

* feature: add CatchVariableReferenceFunction, CatchVariableScopeFunction

* test - common code shared by all variable based reference functions

* test CatchVariableReferenceFunction

src/main/java/spoon/reflect/visitor/filter/CatchVariableReferenceFunction.java

@@ -0,0 +1,49 @@
+/**
+ * Copyright (C) 2006-2017 INRIA and contributors
+ * Spoon - http://spoon.gforge.inria.fr/
+ *
+ * This software is governed by the CeCILL-C License under French law and
+ * abiding by the rules of distribution of free software. You can use, modify
+ * and/or redistribute the software under the terms of the CeCILL-C license as
+ * circulated by CEA, CNRS and INRIA at http://www.cecill.info.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the CeCILL-C License for more details.
+ *
+ * The fact that you are presently reading this means that you have had
+ * knowledge of the CeCILL-C license and that you accept its terms.
+ */
+package spoon.reflect.visitor.filter;
+
+import spoon.reflect.code.CtCatchVariable;
+import spoon.reflect.reference.CtCatchVariableReference;
+import spoon.reflect.visitor.chain.CtConsumableFunction;
+import spoon.reflect.visitor.chain.CtConsumer;
+
+/**
+ * This Query expects a {@link CtCatchVariable} as input
+ * and returns all {@link CtCatchVariableReference}s, which refers this input.
+ * <br>
+ * Usage:<br>
+ * <pre> {@code
+ * CtCatchVariable var = ...;
+ * var
+ *   .map(new CatchVariableReferenceFunction())
+ *   .forEach((CtCatchVariableReference ref)->...process references...);
+ * }
+ * </pre>
+ */
+public class CatchVariableReferenceFunction implements CtConsumableFunction<CtCatchVariable<?>> {
+
+	public CatchVariableReferenceFunction() {
+	}
+
+	@Override
+	public void apply(CtCatchVariable<?> localVariable, CtConsumer<Object> outputConsumer) {
+		localVariable
+			.map(new CatchVariableScopeFunction())
+			.select(new DirectReferenceFilter<CtCatchVariableReference<?>>(localVariable.getReference()))
+			.forEach(outputConsumer);
+	}
+}

src/main/java/spoon/reflect/visitor/filter/CatchVariableScopeFunction.java

@@ -0,0 +1,50 @@
+/**
+ * Copyright (C) 2006-2017 INRIA and contributors
+ * Spoon - http://spoon.gforge.inria.fr/
+ *
+ * This software is governed by the CeCILL-C License under French law and
+ * abiding by the rules of distribution of free software. You can use, modify
+ * and/or redistribute the software under the terms of the CeCILL-C license as
+ * circulated by CEA, CNRS and INRIA at http://www.cecill.info.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the CeCILL-C License for more details.
+ *
+ * The fact that you are presently reading this means that you have had
+ * knowledge of the CeCILL-C license and that you accept its terms.
+ */
+package spoon.reflect.visitor.filter;
+
+import spoon.reflect.code.CtCatch;
+import spoon.reflect.code.CtCatchVariable;
+import spoon.reflect.visitor.chain.CtConsumableFunction;
+import spoon.reflect.visitor.chain.CtConsumer;
+
+/**
+ * This Query expects a {@link CtCatchVariable} as input
+ * and returns all CtElements,
+ * which are in visibility scope of that catch variable.
+ * In other words, it returns all elements,
+ * which might be reference to that catch variable.
+ * <br>
+ * It can be used to search for variable declarations or
+ * variable references which might be in name conflict with input catch variable.
+ * <br>
+ * Usage:<br>
+ * <pre> {@code
+ * CtCatchVariable var = ...;
+ * var.map(new CatchVariableScopeFunction()).forEach(...process result...);
+ * }
+ * </pre>
+ */
+public class CatchVariableScopeFunction implements CtConsumableFunction<CtCatchVariable<?>> {
+
+	public CatchVariableScopeFunction() {
+	}
+
+	@Override
+	public void apply(CtCatchVariable<?> catchVariable, CtConsumer<Object> outputConsumer) {
+		catchVariable.getParent(CtCatch.class).getBody().filterChildren(null).forEach(outputConsumer);
+	}
+}

src/test/java/spoon/test/query_function/QueryTest.java

@@ -22,6 +22,7 @@
 import spoon.reflect.reference.CtExecutableReference;
 import spoon.reflect.reference.CtVariableReference;
 import spoon.reflect.visitor.chain.CtConsumableFunction;
+import spoon.reflect.visitor.filter.CatchVariableReferenceFunction;
 import spoon.reflect.visitor.filter.ParameterReferenceFunction;
 import spoon.test.query_function.testclasses.packageA.ClassA;
 
@@ -95,7 +96,7 @@ class Context {
 		assertEquals(countOfModelClasses, context.classCount);
 	}
 
-	@Test
+  @Test
 	public void testParameterReferenceFunction() throws Exception {
 		//visits all the CtParameter elements whose name is "field" and search for all their references
 		//The test detects whether found references are correct by these two checks:
@@ -110,6 +111,22 @@ public void testParameterReferenceFunction() throws Exception {
 			return false;
 		}).list();
 	}
+
+	@Test
+	public void testCatchVariableReferenceFunction() throws Exception {
+		//visits all the CtCatchVariable elements whose name is "field" and search for all their references
+		//The test detects whether found references are correct by these two checks:
+		//1) the each found reference is on the left side of binary operator and on the right side there is unique reference identification number. Like: (field == 7)
+		//2) the model is searched for all variable references which has same identification number and counts them
+		//Then it checks that counted number of references and found number of references is same 
+		factory.Package().getRootPackage().filterChildren((CtCatchVariable<?> var)->{
+			if(var.getSimpleName().equals("field")) {
+				int value = getLiteralValue(var);
+				checkVariableAccess(var, value, new CatchVariableReferenceFunction());
+			}
+			return false;
+		}).list();
+	}
 
 	private void checkVariableAccess(CtVariable<?> var, int value, CtConsumableFunction<?> query) {
 		class Context {