add wildcard fallback handlers

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024 00asdf, GHXX
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

SimpleHttpServer/HttpServer.cs

@@ -24,7 +24,7 @@ public sealed class HttpServer {
         Port = port;
         conf = configuration;
         listener = new HttpListener();
-        listener.Prefixes.Add($"http://localhost:{port}/");
+        listener.Prefixes.Add($"http://127.0.0.1:{port}/");
         mainLogger = new(LogOutputTopic.Main, conf);
         requestLogger = new(LogOutputTopic.Request, conf);
     }
@@ -89,6 +89,7 @@ public sealed class HttpServer {
     private readonly Dictionary<string, PathTree<EndpointInvocationInfo>> pathEndpointMethodInfosTrees = new(); // reqmethod : pathtree
     private static readonly Type[] expectedEndpointParameterTypes = new[] { typeof(RequestContext) };
     internal static readonly int expectedEndpointParameterPrefixCount = expectedEndpointParameterTypes.Length;
+    private readonly Dictionary<string, Func<RequestContext, Task<bool>>> wildcardFallbackHandlers = new(); // reqmethod : handler
 
     public void RegisterEndpointsFromType<T>(Func<T>? instanceFactory = null) where T : class { // T cannot be static, as generic args must be nonstatic
         if (stringToTypeParameterConverters.Count == 0)
@@ -213,7 +214,7 @@ public sealed class HttpServer {
 
     private readonly Dictionary<Type, IParameterConverter> stringToTypeParameterConverters = new();
 
-    private static string NormalizeUrlPath(string url) {
+    private string NormalizeUrlPath(string url) {
         var fwdSlashUrl = url.Replace('\\', '/');
 
         var segments = fwdSlashUrl.Trim('/').Split('/', StringSplitOptions.RemoveEmptyEntries).ToList();
@@ -242,7 +243,12 @@ public sealed class HttpServer {
         }
         rv.AppendJoin('/', simplifiedSegmentsReversed.Reverse<string>());
 
-        return '/' + (rv.ToString().TrimEnd('/') + (fwdSlashUrl.EndsWith('/') ? "/" : "")).TrimStart('/');
+        var suffix = (rv.ToString().TrimEnd('/') + (fwdSlashUrl.EndsWith('/') ? "/" : "")).TrimStart('/');
+        if (conf.TrimTrailingSlash) {
+            suffix = suffix.TrimEnd('/');
+        }
+
+        return '/' + suffix;
     }
 
     private async Task ProcessRequestAsync(HttpListenerContext ctx) {
@@ -262,8 +268,9 @@ public sealed class HttpServer {
             /* Finding the endpoint that should process the request:
              * 1. Try to see if there is a simple endpoint where request method and path match
              * 2. Otherwise, try to see if a path-parameter-endpoint matches (duplicates throw an error on startup)
-             * 3. Otherwise, check if it is inside a static serve path
+             * 3. Otherwise, check if wildcardFallbackHandlers contains a handler for the current requestMethod. If this method returns false 'request was not handled', continue, otherwise skip all future steps.
-             * 4. Otherwise, show 404 page */
+             * 4. Otherwise, check if it is inside a static serve path
+             * 5. Otherwise, show 404 page */
 
             EndpointInvocationInfo? pathEndpointInvocationInfo = null;
             if (simpleEndpointMethodInfos.TryGetValue(requestMethod, reqPath, out var simpleEndpointInvocationInfo) ||
@@ -328,10 +335,18 @@ public sealed class HttpServer {
                     var splittedReqPath = reqPath[1..].Split('/');
                     for (int i = 0; i < pparams.Count; i++) {
                         var pparam = pparams[i];
+                        string paramValue;
                         if (pparam.IsCatchAll)
-                            convertedMParamValues[pparam.ArgPos] = string.Join('/', splittedReqPath[pparam.SegmentStartPos..]);
+                            paramValue = string.Join('/', splittedReqPath[pparam.SegmentStartPos..]);
                         else
-                            convertedMParamValues[pparam.ArgPos] = splittedReqPath[pparam.SegmentStartPos];
+                            paramValue = splittedReqPath[pparam.SegmentStartPos];
+
+                        if (stringToTypeParameterConverters[pparam.Type].TryConvertFromString(paramValue, out var res))
+                            convertedMParamValues[pparam.ArgPos] = res;
+                        else {
+                            await HandleDefaultErrorPageAsync(rc, HttpStatusCode.BadRequest);
+                            return;
+                        }
                     }
                 }
 
@@ -341,7 +356,17 @@ public sealed class HttpServer {
                 // todo read and convert pathparams
 
                 await (Task) (mi.Invoke(endpointInvocationInfo.typeInstanceReference, convertedMParamValues) ?? throw new NullReferenceException("Website func returned null unexpectedly"));
-            } else { // try to find suitable static serve path
+            } else {
+                // ---------------- check for fallback wildcard handler ----------------
+                if (wildcardFallbackHandlers.TryGetValue(requestMethod, out var handler)) {
+                    var handledByWildcard = await handler.Invoke(rc);
+                    if (handledByWildcard) { // if that handler was able to handle the request, end execution
+                        return;
+                    }
+                }
+                // ---------------------------------------------------------------------
+
+                // try to find suitable static serve path
                 if (requestMethod == "GET")
                     foreach (var (k, v) in staticServePaths) {
                         if (reqPath.StartsWith(k)) { // do a static serve
@@ -402,4 +427,14 @@ public sealed class HttpServer {
             }
         } catch (ObjectDisposedException) { }
     }
+
+    /// <summary>
+    /// Adds a wildcard fallback handler that receives any request that was not matched by a more explicit endpoint. 
+    /// The handler is supposed to return 'true' if the request was handled correctly and thus execution shall end. Return 'false' to try to serve the file from a static-serve path.
+    /// </summary>
+    /// <param name="reqMethod"></param>
+    /// <param name="requestHandler">This method must return whether the reuqest was handled; returning false makes handling act as if this handler never ran</param>
+    public void RegisterWildcardFallbackHandler(HttpRequestType reqMethod, Func<RequestContext, Task<bool>> requestHandler) {
+        wildcardFallbackHandlers.Add(Enum.GetName(reqMethod) ?? throw new NotImplementedException(), requestHandler);
+    }
 }

SimpleHttpServer/SimpleHttpServerConfiguration.cs

@@ -13,6 +13,10 @@ public class SimpleHttpServerConfiguration {
     /// See description of <see cref="DisableLogMessagePrinting"/>
     /// </summary>
     public CustomLogMessageHandler? LogMessageHandler { get; init; } = null;
+    /// <summary>
+    /// If set to true, paths ending with / are identical to paths without said trailing slash. E.g. /index is then the same as /index/
+    /// </summary>
+    public bool TrimTrailingSlash { get; init; } = true;
 
     public SimpleHttpServerConfiguration() { }
 

SimpleHttpServer/Types/PathTree.cs

@@ -22,12 +22,12 @@ internal class PathTree<T> where T : class {
                 throw new Exception($"Found illegal catchall-wildcard in path: '{string.Join('/', path)}'");
             }
 
-            var leafdata = unpackedLeafData[i];
+            var leafdata = unpackedLeafData[i] ?? throw new ArgumentNullException("Leafdata must not be null!");
             rootNode.AddSuccessor(path, leafdata);
         }
     }
 
-    internal bool TryGetPath(string reqPath, [MaybeNullWhen(false)] out T? endpoint) {
+    internal bool TryGetPath(string reqPath, [MaybeNullWhen(false)] out T endpoint) {
         if (rootNode == null) {
             endpoint = null;
             return false;
@@ -58,16 +58,16 @@ internal class PathTree<T> where T : class {
 
         // return found path
         endpoint = currNode.leafData;
-        return true;
+        return endpoint != null;
     }
 
     private class Node {
-        public T? leafData = null;
+        public T? leafData = null; // null means that this is a node without a value (e.g. when it is just part of a path)
         public Dictionary<string, Node>? next = null;
         public Node? pathWildcardNext = null; // path wildcard
         public Node? catchAllNext = null; // trailing-catchall wildcard
 
-        public void AddSuccessor(string[] segments, T? newLeafData) {
+        public void AddSuccessor(string[] segments, T newLeafData) {
             if (segments.Length == 0) { // actually add the data to this node
                 Assert(leafData == null);
                 leafData = newLeafData;
@@ -84,17 +84,14 @@ internal class PathTree<T> where T : class {
                     catchAllNext.AddSuccessor(segments[1..], newLeafData);
                     return;
                 } else { // must be single wildcard otherwise                    
-                    Assert(pathWildcardNext == null);
+                    pathWildcardNext ??= new();
-                    pathWildcardNext = new();
                     pathWildcardNext.AddSuccessor(segments[1..], newLeafData);
                     return;
                 }
             }
 
             // otherwise we want to add a new constant path successor
-            if (next == null) {
+            next ??= new();
-                next = new();
-            }
 
             if (next.TryGetValue(seg, out var existingNode)) {
                 existingNode.AddSuccessor(segments[1..], newLeafData);

SimpleHttpServer/Types/RequestContext.cs

@@ -35,22 +35,23 @@ public class RequestContext : IDisposable {
 
     public void SetStatusCode(HttpStatusCode status) => SetStatusCode((int) status);
 
+    public async Task SetStatusCodeWriteLineDisposeAsync(HttpStatusCode status, string message) {
+        SetStatusCode(status);
+        await WriteLineToRespAsync(message);
+        await RespWriter.FlushAsync();
+    }
+
     public async Task SetStatusCodeAndDisposeAsync(int status) {
         using (this) {
             SetStatusCode(status);
+            if (status != (int)HttpStatusCode.NotModified) { // NotModified must not write any data to response
                 await WriteToRespAsync("\n\n");
                 await RespWriter.FlushAsync();
             }
         }
-
-    public async Task SetStatusCodeAndDisposeAsync(HttpStatusCode status) {
-        using (this) {
-            SetStatusCode((int) status);
-            await WriteToRespAsync("\n\n");
-            await RespWriter.FlushAsync();
-        }
     }
 
+    public async Task SetStatusCodeAndDisposeAsync(HttpStatusCode status) => await SetStatusCodeAndDisposeAsync((int) status);
 
     public async Task SetStatusCodeAndDisposeAsync(int status, string description) {
         using (this) {