public void Validate_InvalidResult_HasAllowedExtensionsValidationContext(string[] allowedExtensions)
        {
            // Arrange
            var validator = new ImageTypeValidator(allowedExtensions);

            // Act
            var result = validator.Validate("", null);

            // Assert
            var expected = string.Join(", ", allowedExtensions);

            Assert.AreEqual(expected, result.AllowedExtensions);
        }
 public ImageTypeValidatorTests()
 {
     _validator = new ImageTypeValidator(".jpg", ".jpeg", ".png", ".gif", ".bmp");
 }