minimal api fails with IParsableValueOf

Author: foresightyj

ValueOf.Extensions.Examples/Models/UserId.cs

@@ -1,27 +1,37 @@
+using System.ComponentModel;
 using System.Diagnostics.CodeAnalysis;
 
 namespace ValueOf.Extensions.Examples;
 
-public interface IValueOfParsable<TU, T> : IParsable<T> where T : ValueOf<TU, T>, IParsable<T>, new()
+public interface IParsableValueOf<TU, T> : IParsable<T> where T : ValueOf<TU, T>, IParsable<T>, new()
 {
-    public static T Parse(string s, IFormatProvider? provider)
+    static T IParsable<T>.Parse(string s, IFormatProvider? provider)
     {
-        throw new NotImplementedException();
+        var converter = TypeDescriptor.GetConverter(typeof(T));
+        return (T)converter.ConvertFrom(s)!;
     }
 
-    public static bool TryParse([NotNullWhen(true)] string? s, IFormatProvider? provider, [MaybeNullWhen(false)] out T result)
+    static bool IParsable<T>.TryParse([NotNullWhen(true)] string? s, IFormatProvider? provider,
+        [MaybeNullWhen(false)] out T result)
     {
-        throw new NotImplementedException();
+        result = default(T);
+        var converter = TypeDescriptor.GetConverter(typeof(T));
+        if (converter.CanConvertFrom(typeof(string)))
+        {
+            result = (T)converter.ConvertFrom(s)!;
+            return true;
+        }
+
+        return false;
     }
 }
 
-public sealed class UserId : ValueOf<int, UserId>, IValueOfParsable<int, UserId>
+public sealed class UserId : ValueOf<int, UserId>, IParsableValueOf<int, UserId>
 {
     protected override void Validate()
     {
         var userId = Value;
         if (userId <= 0)
             throw new ArgumentOutOfRangeException(nameof(userId) + $" must be positive integer but is: {userId}");
     }
-
 }

ValueOf.Extensions.Examples/Program.cs

@@ -50,22 +50,16 @@
 
 app.MapControllers();
 
-app.MapGet("/searchUsers",
-    async ([FromServices] DemoDbContext _dbContext, [FromQuery] UserId? userId, [FromQuery] EmailAddress? email) =>
+app.MapGet("/searchUsers", async ([FromServices] DemoDbContext dbContext, [FromQuery] UserId? userId) =>
+{
+    IQueryable<User> q = dbContext.Users;
+    if (userId != null)
     {
-        IQueryable<User> q = _dbContext.Users;
-        if (userId != null)
-        {
-            q = q.Where(u => u.Id == userId);
-        }
-
-        if (email != null)
-        {
-            q = q.Where(u => u.Email == email);
-        }
+        q = q.Where(u => u.Id == userId);
+    }
 
-        return q.ToList();
-    });
+    return q.ToList();
+});
 
 
 app.Run();