In order to give a nicer developer experience composing validation messages there are broad categories of libraries that either work well in a Java/C# style setting or work well when composing functions. Attribute based validation libraries The default style that can be seen in many java and C# projects is the attribute based validation approach. public class Person { [MinLength(1,ErrorMessage ="NameBetween1And50"), MaxLength(50,ErrorMessage ="NameBetween1And50")] public string Name{get;set;} [Ema[...]

Problems How do you create an instance of a given readonly class? How do you get a new instance but with given fields with different values? Writing readonly record classes 2007 Around 2007 I wrestled with writing immutable classes in c#. One of the key painpoints was that the constructor parameters for a class representing a database row for a specific table ended up with around 68 parameters. Note that we already had code generation of SQL Reader row deserialization based on SQL information tab[...]

Problems How do you create an instance of a given readonly class? How do you get a new instance but with given fields with different values? Writing readonly record classes 2007 Around 2007 I wrestled with writing immutable classes in C#. One of the key painpoints was that the constructor parameters for a class representing a database row for a specific table ended up with around 68 parameters. Note that we already had code generation of SQL Reader row deserialization based on SQL information tab[...]

After writing the previous posts about getting some of the infrastructure working for non Windows systems, I’ve seen better ways of getting it to work. Instead of using a netfx.props file, you can use a Directory.Build.props with platform specific configuration as seen in for instance FSharp.Compiler.Service: <Project> <!-- mono --> <PropertyGroup Condition="'$(OS)' == 'Unix'"> <MonoRoot Condition="'$(MonoRoot)' == '' and $([MSBuild]::IsOsPlatform('Linux'))">/usr</MonoRoot> <MonoRoot Conditio[...]

After writing the previous posts about getting some of the infrastructure working for non Windows systems, I’ve seen better ways of getting it to work. Instead of using a netfx.props file, you can use a Directory.Build.props with platform specific configuration as seen in for instance FSharp.Compiler.Service: <Project> <!-- mono --> <PropertyGroup Condition="'$(OS)' == 'Unix'"> <MonoRoot Condition="'$(MonoRoot)' == '' and $([MSBuild]::IsOsPlatform('Linux'))">/usr</MonoRoot> <MonoRoot Conditio[...]