CalculatorTests.java

import static org.junit.Assert.*;

import org.junit.Before;
import org.junit.Test;

public class OsheroveTests {
	private Calculator calculator;

	@Before
	public void setUp() throws Exception {
		StringFormat format = new MultiCharDelimiter(
				new SelfDescribingList(
						new VanillaNumbersList()));

		NumberValidator[] numberRules = {
			new PreventNegatives(),
			new IgnoreThousands()
		};
		this.calculator = new Calculator(format, new NonZeroFunction(
				new ArraySum(new NumberParser(numberRules))));
	}

	@Test
	public void addsNumbers() {
		assertEquals(0, calculator.add(""));
		assertEquals(1, calculator.add("1"));
		assertEquals(3, calculator.add("1,2"));
	}

	@Test
	public void addsManyNumbers() {
		assertEquals(290, calculator.add("1,2,34,56,7,89,101"));
	}

	@Test
	public void allowsNewlineAsSeparator() {
		assertEquals(12, calculator.add("3\n4\n5"));
	}

	@Test
	public void supportArbitraryDelimiters() throws Exception {
		assertEquals(3, calculator.add("//;\n1;2"));
		assertEquals(7, calculator.add("//@\n3@4"));
	}

	@Test(expected = NegativesNotAllowed.class)
	public void negativesNotAllowed() throws Exception {
		calculator.add("//;\n1;2;-1");
	}

	@Test(expected = NegativesNotAllowed.class)
	public void loneNegativeNotAllowed() throws Exception {
		calculator.add("-1");
	}

	@Test
	public void ignoreNumbersGreaterThan1000() throws Exception {
		assertEquals(2, calculator.add("2,1003"));
	}

	@Test
	public void longerDelimiters() throws Exception {
		assertEquals(6, calculator.add("//[***]\n1***2***3"));
	}

}