Switch over to a check-based system with multi attribute support

SimpleHttpServer/Types/BaseEndpointCheckAttribute.cs

@@ -0,0 +1,15 @@
+using System.Net;
+
+namespace SimpleHttpServer.Types;
+
+[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class, Inherited = true, AllowMultiple = true)]
+public abstract class BaseEndpointCheckAttribute : Attribute {
+
+    public BaseEndpointCheckAttribute() { }
+
+    /// <summary>
+    /// Executed when the endpoint is invoked. The endpoint invocation is skipped if any of the checks fail.
+    /// </summary>
+    /// <returns>True to allow invocation, false to prevent.</returns>
+    public abstract bool Check(HttpListenerRequest req);
+}

SimpleHttpServer/Types/EndpointInvocationInfo.cs

@@ -1,12 +1,19 @@
-using System.Reflection;
+using System.Net;
+using System.Reflection;
 
 namespace SimpleHttpServer.Types;
-internal struct EndpointInvocationInfo {
-    internal readonly MethodInfo methodInfo;
-    internal readonly List<(string, (Type type, bool isOptional))> queryParameters;
+internal readonly struct EndpointInvocationInfo {
+    internal record struct QueryParameterInfo(string Name, Type Type, bool IsOptional);
 
-    public EndpointInvocationInfo(MethodInfo methodInfo, List<(string, (Type type, bool isOptional))> queryParameters) {
+    internal readonly MethodInfo methodInfo;
+    internal readonly List<QueryParameterInfo> queryParameters;
+    internal readonly BaseEndpointCheckAttribute[] requiredChecks;
+
+    public EndpointInvocationInfo(MethodInfo methodInfo, List<QueryParameterInfo> queryParameters, BaseEndpointCheckAttribute[] requiredChecks) {
         this.methodInfo = methodInfo ?? throw new ArgumentNullException(nameof(methodInfo));
         this.queryParameters = queryParameters ?? throw new ArgumentNullException(nameof(queryParameters));
+        this.requiredChecks = requiredChecks;
     }
+
+    public readonly bool CheckAll(HttpListenerRequest req) => requiredChecks.All(x => x.Check(req));
 }