import java.util.Arrays;
import java.util.stream.Collectors;

import org.junit.Test;
import org.junit.Assert;

public class SimpleTest {

    InfixToPostfix fixer = new StackInfixToPostfix();

    private String infixToPostfix(String infix) {
        return fixer.infixToPostfix(Arrays.asList(infix.split(" ")))
                    .stream().collect(Collectors.joining(" "));
    }

    @Test
    public void testConstant() {
        Assert.assertEquals("123", infixToPostfix("123"));
    }

    @Test
    public void testAddition() {
        Assert.assertEquals("1 2 +", infixToPostfix("1 + 2"));
    }

    @Test
    public void testSubstraction() {
        Assert.assertEquals("1 2 -", infixToPostfix("1 - 2"));
    }

    @Test
    public void testMultiplication() {
        Assert.assertEquals("1 2 *", infixToPostfix("1 * 2"));
    }

    @Test
    public void testDivision() {
        Assert.assertEquals("1 2 /", infixToPostfix("1 / 2"));
    }

    @Test
    public void testParenthesisLeft() {
        Assert.assertEquals("1 2 3 + *", infixToPostfix("1 * ( 2 + 3 )"));
    }

    @Test
    public void testParenthesisRight() {
        Assert.assertEquals("1 2 + 3 *", infixToPostfix("( 1 + 2 ) * 3"));
    }

}