public void GivenDonationOfZero_ReturnZeroGiftAidAmount()
        {
            _giftAidEvaluator = new GiftAidEvaluator(_taxRateValueSource.Object);
            var result = _giftAidEvaluator.Calculate(0);

            Assert.AreEqual(0, result);
        }
 private void SetUpSystemUnderTest(decimal taxRateValue, decimal supplementPercentageValue)
 {
     _giftAidEvaluator = new GiftAidEvaluator(_taxRateValueSource.Object, _giftAidSupplementer.Object);
     _taxRateValueSource.Setup(x => x.CurrentTaxRate).Returns(taxRateValue);
     _giftAidSupplementer.Setup(x => x.SupplementPercentage).Returns(supplementPercentageValue);
 }
 private void SetUpSystemUnderTest(decimal taxRateValue)
 {
     _giftAidEvaluator = new GiftAidEvaluator(_taxRateValueSource.Object);
     _taxRateValueSource.Setup(x => x.CurrentTaxRate).Returns(taxRateValue);
 }