SwitchExpressionTest.java

/*
Copyright (c) 2008 Arno Haase, Andr� Arnold.
All rights reserved. This program and the accompanying materials
are made available under the terms of the Eclipse Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/epl-v10.html

Contributors:
    Arno Haase - initial API and implementation
    Andr� Arnold
 */
package org.eclipse.xtend.backend.expr;

import static org.eclipse.xtend.backend.testhelpers.BackendTestHelper.SOURCE_POS;
import static org.eclipse.xtend.backend.testhelpers.BackendTestHelper.createEmptyExecutionContext;
import static org.eclipse.xtend.backend.testhelpers.BackendTestHelper.createEmptyFdc;
import static org.junit.Assert.assertEquals;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.xtend.backend.common.ExecutionContext;
import org.eclipse.xtend.backend.common.ExpressionBase;
import org.eclipse.xtend.backend.common.NamedFunction;
import org.eclipse.xtend.backend.functions.FunctionDefContextInternal;
import org.eclipse.xtend.backend.testhelpers.CheckEvaluationExpression;
import org.eclipse.xtend.backend.testhelpers.NamedFunctionFactory;
import org.eclipse.xtend.backend.types.CompositeTypesystem;
import org.eclipse.xtend.backend.types.builtin.StringType;
import org.eclipse.xtend.backend.util.Pair;
import org.junit.Test;


/**
 * 
 * @author Arno Haase (http://www.haase-consulting.com)
 * @author Andr� Arnold
 */
public class SwitchExpressionTest {
    
    @Test public void testLogic () {
        final CheckEvaluationExpression switchExpr = new CheckEvaluationExpression ("a");
        
        final CheckEvaluationExpression caseAExpr = new CheckEvaluationExpression ("a"); 
        final CheckEvaluationExpression valueAExpr = new CheckEvaluationExpression ("aValue"); 
        
        final CheckEvaluationExpression caseBExpr = new CheckEvaluationExpression ("b"); 
        final CheckEvaluationExpression valueBExpr = new CheckEvaluationExpression ("bValue"); 
        
        final CheckEvaluationExpression defaultExpr = new CheckEvaluationExpression ("defaultValue");
        
        final List<Pair<ExpressionBase, ExpressionBase>> cases = new ArrayList<Pair<ExpressionBase,ExpressionBase>> ();
        cases.add (new Pair<ExpressionBase, ExpressionBase> (caseAExpr, valueAExpr));
        cases.add (new Pair<ExpressionBase, ExpressionBase> (caseBExpr, valueBExpr));
        
        final SwitchExpression expr = new SwitchExpression (switchExpr, cases, defaultExpr, SOURCE_POS);
        
        assertEquals ("aValue", expr.evaluate (createEmptyExecutionContext()));
        assertEquals (1, switchExpr._evalCounter);
        assertEquals (1, caseAExpr._evalCounter);
        assertEquals (1, valueAExpr._evalCounter);
        assertEquals (0, caseBExpr._evalCounter);
        assertEquals (0, valueBExpr._evalCounter);
        assertEquals (0, defaultExpr._evalCounter);
        
        switchExpr._value = "b";
        assertEquals ("bValue", expr.evaluate (createEmptyExecutionContext()));
        assertEquals (2, switchExpr._evalCounter);
        assertEquals (2, caseAExpr._evalCounter);
        assertEquals (1, valueAExpr._evalCounter);
        assertEquals (1, caseBExpr._evalCounter);
        assertEquals (1, valueBExpr._evalCounter);
        assertEquals (0, defaultExpr._evalCounter);
        
        switchExpr._value = "c";
        assertEquals ("defaultValue", expr.evaluate (createEmptyExecutionContext()));
        assertEquals (3, switchExpr._evalCounter);
        assertEquals (3, caseAExpr._evalCounter);
        assertEquals (1, valueAExpr._evalCounter);
        assertEquals (2, caseBExpr._evalCounter);
        assertEquals (1, valueBExpr._evalCounter);
        assertEquals (1, defaultExpr._evalCounter);
        
        switchExpr._value = null;
        assertEquals ("defaultValue", expr.evaluate (createEmptyExecutionContext()));
        assertEquals (4, switchExpr._evalCounter);
        assertEquals (4, caseAExpr._evalCounter);
        assertEquals (1, valueAExpr._evalCounter);
        assertEquals (3, caseBExpr._evalCounter);
        assertEquals (1, valueBExpr._evalCounter);
        assertEquals (2, defaultExpr._evalCounter);
    }

    @Test public void testUsesOperatorEquals () {
        final CheckEvaluationExpression switchExpr = new CheckEvaluationExpression ("xyz");
        
        final CheckEvaluationExpression caseAExpr = new CheckEvaluationExpression ("a"); 
        final CheckEvaluationExpression valueAExpr = new CheckEvaluationExpression ("aValue"); 
        
        final CheckEvaluationExpression defaultExpr = new CheckEvaluationExpression ("defaultValue");
        
        final List<Pair<ExpressionBase, ExpressionBase>> cases = new ArrayList<Pair<ExpressionBase,ExpressionBase>> ();
        cases.add (new Pair<ExpressionBase, ExpressionBase> (caseAExpr, valueAExpr));
        
        final SwitchExpression expr = new SwitchExpression (switchExpr, cases, defaultExpr, SOURCE_POS);

        
        // register an equals function that returns "true" for any two strings
        final NamedFunction myStringEquals = new NamedFunctionFactory ("operatorEquals", StringType.INSTANCE, StringType.INSTANCE) {
            public Object invoke (ExecutionContext ctx, Object[] params) {
                return true;
            }
        }.create(); 
        
        final FunctionDefContextInternal fdc = createEmptyFdc (new CompositeTypesystem ());
        fdc.register (myStringEquals, true);
        
        final ExecutionContext ctx = createEmptyExecutionContext();
        assertEquals ("defaultValue", expr.evaluate (ctx));
        
        ctx.setFunctionDefContext(fdc);
        assertEquals ("aValue", expr.evaluate (ctx));
    }
}