ConcatExpressionTest.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.eclipse.xtend.backend.testhelpers.BackendTestHelper.createLiteral;
import static org.junit.Assert.assertEquals;

import java.util.Arrays;

import org.eclipse.xtend.backend.common.ExecutionContext;
import org.eclipse.xtend.backend.common.ExpressionBase;
import org.eclipse.xtend.backend.common.Helpers;
import org.eclipse.xtend.backend.common.NamedFunction;
import org.eclipse.xtend.backend.functions.FunctionDefContextInternal;
import org.eclipse.xtend.backend.testhelpers.NamedFunctionFactory;
import org.eclipse.xtend.backend.types.CompositeTypesystem;
import org.eclipse.xtend.backend.types.builtin.ObjectType;
import org.junit.Test;


/**
 * 
 * @author Arno Haase (http://www.haase-consulting.com)
 * @author Andr� Arnold
 */
public class ConcatExpressionTest {
    @Test public void testLogic () {
        assertEquals ("", eval ());
        assertEquals ("abc", eval (createLiteral ("abc")));
        assertEquals ("abc", eval (createLiteral ("a"), createLiteral ("b"), createLiteral ("c")));
        assertEquals ("123", eval (createLiteral (1), createLiteral (2), createLiteral (3)));
        assertEquals ("123", eval (createLiteral (1), createLiteral ("2"), createLiteral (3)));
        assertEquals ("", eval (createLiteral (null)));
        assertEquals ("a", eval (createLiteral (null), createLiteral ("a")));
    }
    
    private Object eval (ExpressionBase... parts) {
        return new ConcatExpression (Arrays.asList(parts), SOURCE_POS).evaluate (createEmptyExecutionContext()).toString();
    }
    
    @Test public void testUsesToStringExtension () {
        final NamedFunction myToString = new NamedFunctionFactory (Helpers.TO_STRING_METHOD_NAME.getSimpleName(), ObjectType.INSTANCE) {
            public Object invoke (ExecutionContext ctx, Object[] params) {
                return "#" + params[0] + "!";
            }
        }.create(); 
        
        final FunctionDefContextInternal fdc = createEmptyFdc (new CompositeTypesystem ());
        fdc.register (myToString, true);

        final ExpressionBase expr = new ConcatExpression (Arrays.asList (createLiteral("a"), createLiteral("b")), SOURCE_POS);
        
        final ExecutionContext ctx = createEmptyExecutionContext();
        assertEquals ("ab", expr.evaluate(ctx).toString());
        
        ctx.setFunctionDefContext(fdc);
        assertEquals ("#a!#b!", expr.evaluate(ctx).toString());
    }
}