code_coverage_10.java

public class CalcControllerTest {

  @Test
  public void result() {
    CalcController c = new CalcController(new Calculator() {
      @Override
      public double process(String expression) {
        if (expression.equals("1 + 1")) {
          return 2;
        }
        if (expression.equals("+")) {
          throw new CalculatorException("Invalid expression: +");
        }
        throw new CalculatorException("Unexpected input: "+ expression);
      }
    });
    assertEquals("2.0", c.result("1 + 1"));
    assertEquals("Invalid expression: +", c.result("+"));
  }
}