feat: add minimal api sample for primitive obsession prevention

README.md

@@ -50,7 +50,7 @@ You can find samples on new features available in ASP.NET Core 9(3) [here](/proj
 | [Localization and Globalization](/projects/localization)                | 6  |                                                                              |
 | [Middleware](/projects/middleware)                                      | 14 |                                                                              |
 | [Mini Apps](/projects/mini)                                             | 2  |                                                                              |
-| [Minimal API](/projects/minimal-api)                                    | 36 | Routing, Parameter Bindings, etc                                             |
+| [Minimal API](/projects/minimal-api)                                    | 37 | Routing, Parameter Bindings, etc                                             |
 | [Minimal Hosting](/projects/minimal-hosting)                            | 23 |                                                                              |
 | [MVC](/projects/mvc)                                                    | 47 | Localization, Routing, Razor Class Library, Tag Helpers, View Component, etc |
 | [Output Cache Middleware](/projects/output-cache-middleware)            |    |                                                                              |
@@ -72,7 +72,7 @@ You can find samples on new features available in ASP.NET Core 9(3) [here](/proj
 | [Syndications](/projects/syndications)                                  | 3  |                                                                              |
 | [Testing](/projects/testing)                                            | 1  |                                                                              |
 | [Unpoly](/projects/unpoly)                                              | 5  |                                                                              |
-| [URL Redirect/Rewrite](/projects/rewrite)                               | 6  |                                                                              |
+| https://weblogs.asp.net/owscott/rewrite-vs-redirect-what-s-the-difference(/projects/rewrite)                               | 6  |                                                                              |
 | [Uri Helper](/projects/uri-helper)                                      | 5  |                                                                              |
 | [Windows Service](/projects/windows-service)                            | 1  |                                                                              |
 | [Web Sockets](/projects/web-sockets)                                    | 6  |                                                                              |
@@ -85,6 +85,12 @@ You can find samples on new features available in ASP.NET Core 9(3) [here](/proj
 
 To run these samples, simply open your command line console, go to each folder and execute `dotnet watch run`.
 
+### Minimal API (37)
+
+- [Primitive Obsession Prevention](./projects/minimal-api/primitive-obsession)
+
+  This sample demonstrates how to prevent **Primitive Obsession** by using **Value Objects** and the `static TryParse` pattern for automatic parameter binding in Minimal APIs.
+
 ### Misc (6)
 
 -   [Application Environment](/projects/application-environment)
@@ -166,6 +172,4 @@ All these samples require `SixLabors.ImageSharp.Web` middleware package. This mi
 ## Misc
 
 -   [Contributor Guidelines](https://github.com/dodyg/practical-aspnetcore/blob/master/CONTRIBUTING.md)
--   [Code of Conduct](https://github.com/dodyg/practical-aspnetcore/blob/master/CODE_OF_CONDUCT.md)
-
-
+-   [Code of Conduct](https://github.com/dodyg/practical-aspnetcore/blob/master/CODE_OF_CONDUCT.md)

global.json

@@ -4,4 +4,5 @@
     "rollForward": "major",
     "allowPrerelease": true
   }
+
 }

projects/minimal-api/Primitive-Obsession/Primitive-Obsession.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.14.36414.22 d17.14
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Primitive-Obsession", "Primitive-Obsession\Primitive-Obsession.csproj", "{3722E737-D7F9-444B-BB09-C4B80452ACB4}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{3722E737-D7F9-444B-BB09-C4B80452ACB4}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3722E737-D7F9-444B-BB09-C4B80452ACB4}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3722E737-D7F9-444B-BB09-C4B80452ACB4}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3722E737-D7F9-444B-BB09-C4B80452ACB4}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {A9FE2ACE-83FF-4EDA-A57F-2237F9A761E7}
+	EndGlobalSection
+EndGlobal

projects/minimal-api/Primitive-Obsession/Primitive-Obsession/Primitive-Obsession.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <RootNamespace>Primitive_Obsession</RootNamespace>
+  </PropertyGroup>
+
+</Project>

projects/minimal-api/Primitive-Obsession/Primitive-Obsession/Program.cs

@@ -0,0 +1,60 @@
+var builder = WebApplication.CreateBuilder(args);
+var app = builder.Build();
+
+// -------------------------------
+// CASE 1: Primitive Obsession
+// -------------------------------
+// We rely on primitive types (string) to represent a domain concept.
+// This forces validation logic to be repeated everywhere.
+
+app.MapPost("/orders-bad", (string email) =>
+{
+if (string.IsNullOrWhiteSpace(email) || !email.Contains("@"))
+return Results.BadRequest("Invalid email address");
+
+return Results.Ok($"Order placed for {email}");
+});
+
+
+// -------------------------------
+// CASE 2: Value Object
+// -------------------------------
+// We represent the concept using a dedicated type.
+// ASP.NET Core will use TryParse during model binding.
+
+app.MapPost("/orders-good", (EmailAddress email) =>
+{
+// If execution reaches here, the email is guaranteed to be valid
+return Results.Ok($"Order placed for {email.Value}");
+});
+
+
+app.Run();
+
+
+// -------------------------------
+// Value Object
+// -------------------------------
+public sealed record EmailAddress
+{
+    public string Value { get; }
+
+    private EmailAddress(string value)
+    {
+        Value = value;
+    }
+
+    // ASP.NET Core Minimal APIs automatically use TryParse
+    // during parameter binding.
+    public static bool TryParse(string? value, out EmailAddress? result)
+    {
+        if (!string.IsNullOrWhiteSpace(value) && value.Contains("@"))
+        {
+            result = new EmailAddress(value);
+            return true;
+        }
+
+        result = null;
+        return false;
+    }
+}

projects/minimal-api/Primitive-Obsession/Primitive-Obsession/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

projects/minimal-api/Primitive-Obsession/Primitive-Obsession/appsettings.json

@@ -0,0 +1,9 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "AllowedHosts": "*"
+}