StereoDetectorTest.java

package stereo;

import java.util.List;

import org.junit.Assert;
import org.openscience.cdk.CDKTestCase;
import org.openscience.cdk.DefaultChemObjectBuilder;
import org.openscience.cdk.interfaces.IAtom;
import org.openscience.cdk.interfaces.IAtomContainer;
import org.openscience.cdk.interfaces.IAtomParity;
import org.openscience.cdk.interfaces.IChemObjectBuilder;

public class StereoDetectorTest extends CDKTestCase {
    
    /**
     * Test with methyl-,ethyl-,propyl-,butyl-methane
     */
    public void testCarbonOnlyEnantiomer() {
        IChemObjectBuilder builder = DefaultChemObjectBuilder.getInstance(); 
        IAtomContainer ac = builder.newAtomContainer();
        IAtom centralCarbon = builder.newAtom("C");
        ac.addAtom(centralCarbon);
        
        IAtom methyl = builder.newAtom("C");
        ac.addAtom(methyl);
        ac.addBond(builder.newBond(centralCarbon, methyl));
        
        IAtom ethylA = builder.newAtom("C");
        IAtom ethylB = builder.newAtom("C");
        ac.addAtom(ethylA);
        ac.addAtom(ethylB);
        ac.addBond(builder.newBond(ethylA, ethylB));
        ac.addBond(builder.newBond(centralCarbon, ethylA));
        
        IAtom propylA = builder.newAtom("C");
        IAtom propylB = builder.newAtom("C");
        IAtom propylC = builder.newAtom("C");
        ac.addAtom(propylA);
        ac.addAtom(propylB);
        ac.addAtom(propylC);
        ac.addBond(builder.newBond(propylA, propylB));
        ac.addBond(builder.newBond(propylB, propylC));
        ac.addBond(builder.newBond(centralCarbon, propylA));

        
        IAtom butylA = builder.newAtom("C");
        IAtom butylB = builder.newAtom("C");
        IAtom butylC = builder.newAtom("C");
        IAtom butylD = builder.newAtom("C");
        ac.addAtom(butylA);
        ac.addAtom(butylB);
        ac.addAtom(butylC);
        ac.addAtom(butylD);
        ac.addBond(builder.newBond(butylA, butylB));
        ac.addBond(builder.newBond(butylB, butylC));
        ac.addBond(builder.newBond(butylC, butylD));
        ac.addBond(builder.newBond(centralCarbon, butylA));

        List<IAtomParity> centers = StereoDetector.findStereoCenters(ac);
        Assert.assertEquals(centers.size(), 1);
        Assert.assertEquals(centers.get(0), centralCarbon);
    }
}