public void EvaluateShouldThrowTheExpectedExceptionIfOnlyOperandIsSpecified()
{
var factory = new Mock<IOperationFactory>();
var calculator = new Calculator(factory.Object);
var expression = new[] { "+" };
Assert.Throws<Exception>(() => calculator.Evaluate(expression));
}
public void EvaluateShouldThrowTheExpectedExceptionIfTwoOperandsAreSpecifiedAfterConstant()
{
var factory = new Mock<IOperationFactory>();
var calculator = new Calculator(factory.Object);
var expression = new[] { "10", "+", "+" };
Assert.Throws<Exception>(() => calculator.Evaluate(expression));
}
public void EvaluateShouldReturnConstantIfOnlyConstantIsSpecified()
{
var factory = new Mock<IOperationFactory>();
var calculator = new Calculator(factory.Object);
var expression = new[] { Value1.ToString() };
Assert.AreEqual(Value1, calculator.Evaluate(expression));
}
public void EvaluateShouldWorkCorrectly()
{
const int expectedResult1 = 30;
const int expectedResult = 90;
const string token1 = "+";
const string token2 = "*";
// Here you can test the internal algorithm and expected behavior
// up to the way that methods should be called in the expected order
// on mocks.
// Though - be very careful. As you can see the test setup may grow
// very quickly which implies that future maintenance may be very difficult.
var sequence = new MockSequence();
var factory = new Mock<IOperationFactory>(MockBehavior.Strict);
var operation1 = new Mock<IOperation>(MockBehavior.Strict);
var operation2 = new Mock<IOperation>(MockBehavior.Strict);
factory.InSequence(sequence).Setup(f => f.Create(token2)).Returns(operation2.Object).Verifiable();
factory.InSequence(sequence).Setup(f => f.Create(token1)).Returns(operation1.Object).Verifiable();
operation1.InSequence(sequence).Setup(o => o.Evaluate(10, 10)).Returns(expectedResult1).Verifiable();
operation2.InSequence(sequence).Setup(o => o.Evaluate(expectedResult1, 30)).Returns(expectedResult).Verifiable();
var calculator = new Calculator(factory.Object);
var expression = new[] { "10", token1, "10", token2, "30" };
Assert.AreEqual(expectedResult, calculator.Evaluate(expression));
factory.VerifyAll();
operation1.VerifyAll();
operation2.VerifyAll();
}