public class When_the_IbanValidator_is_told_to_Validate
    {
        [Fact]
        public void It_should_return_an_error_when_there_is_no_value_provided()
        {
            // Assert
            const string value = "";
            var validator = new IbanValidator();

            // Act
            var result = validator.Validate(value);

            // Assert
            Assert.Equal(ValidationResult.ValueMissing, result);
        }

        [Fact]
        public void It_should_return_an_error_when_the_value_length_is_to_short()
        {
            // Assert
            const string value = "BE1800165492356";
            var validator = new IbanValidator();

            // Act
            var result = validator.Validate(value);

            // Assert
            Assert.Equal(ValidationResult.ValueTooSmall, result);
        }

        [Fact]
        public void It_should_return_an_error_when_the_value_length_is_to_big()
        {
            // Assert
            const string value = "BE180016549235656";
            var validator = new IbanValidator();

            // Act
            var result = validator.Validate(value);

            // Assert
            Assert.Equal(ValidationResult.ValueTooBig, result);
        }

        [Fact]
        public void It_should_return_an_error_when_the_value_fails_the_module_check()
        {
            // Assert
            const string value = "BE18001654923566";
            var validator = new IbanValidator();

            // Act
            var result = validator.Validate(value);

            // Assert
            Assert.Equal(ValidationResult.ValueFailsModule97Check, result);
        }

        [Fact]
        public void It_should_return_an_error_when_an_unkown_country_prefix_used()
        {
            // Assert
            const string value = "XX82WEST12345698765432";
            var validator = new IbanValidator();

            // Act
            var result = validator.Validate(value);

            // Assert
            Assert.Equal(ValidationResult.CountryCodeNotKnown, result);
        }

        [Fact]
        public void It_should_return_valid_when_a_valid_value_is_provided()
        {
            // Assert
            const string value = "BE18001654923565";
            var validator = new IbanValidator();

            // Act
            var result = validator.Validate(value);

            // Assert
            Assert.Equal(ValidationResult.IsValid, result);
        }

        [Fact]
        public void It_should_return_valid_when_a_valid_foreign_value_is_provided()
        {
            // Assert
            const string value = "GB82WEST12345698765432";
            var validator = new IbanValidator();

            // Act
            var result = validator.Validate(value);

            // Assert
            Assert.Equal(ValidationResult.IsValid, result);
        }
    }