public async Task GET_DIFFERENCE_BETWEEN_PEOPLE_BOTH_MISSING_PERSON_EXPECT_FAILURE()
        {
            var mockConfig = new Mock <IConfiguration>();

            mockConfig.Setup(x => x["BookLocation"]).Returns(projectDirectory + "/Data/AddressBook");

            var addressBook   = new AddressBookStore(mockLogger, mockConfig.Object);
            var processor     = new AddressBookProcessor(addressBook);
            var ageDifference = await processor.GetAgeDifference("Ted", "Bob the Builder");

            Assert.False(ageDifference.IsSuccessful);
            Assert.Equal("Ted does not exist in the database", ageDifference.Message);
        }
        public async Task GET_DIFFERENCE_BETWEEN_TWO_EXISTING_PEOPLE_EXPECT_YOUNGER()
        {
            var mockConfig = new Mock <IConfiguration>();

            mockConfig.Setup(x => x["BookLocation"]).Returns(projectDirectory + "/Data/AddressBook");

            var addressBook   = new AddressBookStore(mockLogger, mockConfig.Object);
            var processor     = new AddressBookProcessor(addressBook);
            var ageDifference = await processor.GetAgeDifference("John Snow", "Chuck Jackson");

            Assert.True(ageDifference.IsSuccessful);
            Assert.Equal(-945, ageDifference.Difference);
            Assert.Equal("John Snow is 945 days younger than Chuck Jackson", ageDifference.Message);
        }