FluentValidation 9.0.0-preview4

FluentValidation 9 is a major release. Please read the upgrade notes at https://docs.fluentvalidation.net/en/latest/upgrading-to-9.html

Changes in 9.0.0:

• Removed support for netstandard1.1 and netstandard1.6
• Removed support for end-of-life .NET Core versions (2.2 and 3.0). LTS versions are supported (2.1 and 3.1)
• Default email validation mode now uses the same logic as ASP.NET Core. Previous regex behaviour is opt-in.
• TestHelper advanced mode now has more features (see https://docs.fluentvalidation.net/en/latest/testing.html#advanced-test-extensions)
• Equal/NotEqual now perform ordinal comparison when used with string properties
• Severity can now be set dynamically with a callback
• Removed WithLocalizedMessage (WithMessage that takes a callback is the replacement)
• Removed ResourceName from ValidationFailure
• Removed ResourceName and ResourceType from IStringSource.
• Removed SetCollectionValidator which was deprecated in 8.0
• Additional overload of OnAnyFailure that can receive a collection of validation failures
• Remove DisplayAttribute integration and reference to DataAnnotations.
• ComparisonProperty placeholder is now formatted like PropertyName
• Translations of default error messages into other languages are now lazily-loaded
• Added Slovenian translations of default error messages.
• Added Icelandic translations of default error messages.
• Added WithMessageArgument to the test helpers.
• Add additional overload of SetValidator that takes a Func that receives the current property value.
• ASP.NET Core: FluentValidationModelValidatorProvider and FluentValidationModelValidator are now public.
• Work around a bug in ASP.NET Core's integration testing components that can cause ConfigureServices to run multiple times.
• SourceLink integration.
• placeholder can now be accessed in child validators.
• Additional ValidationException constructor that allows using both the default message and a custom one together.
• ScalePrecisionValidator algorithm now matches SQL Server.
• Additional overload of the When methods that contain the validation context.

Full release notes can be found at https://github.com/FluentValidation/FluentValidation/blob/master/Changelog.txt