Sanitize local function names in tools

Author: kzu

readme.md

@@ -264,6 +264,11 @@ else
 }
 ```
 
+> [!IMPORTANT]
+> The `ToolFactory` will also automatically sanitize the tool name 
+> when using local functions to avoid invalid characters and honor 
+> its original name.
+
 ## Console Logging
 
 Additional `UseJsonConsoleLogging` extension for rich JSON-formatted console logging of AI requests 

src/AI.Tests/ToolsTests.cs

@@ -9,6 +9,16 @@ public class ToolsTests(ITestOutputHelper output)
 {
     public record ToolResult(string Name, string Description, string Content);
 
+    [Fact]
+    public void SanitizesToolName()
+    {
+        static void DoSomething() { }
+
+        var tool = ToolFactory.Create(DoSomething);
+
+        Assert.Equal("do_something", tool.Name);
+    }
+
     [SecretsFact("OPENAI_API_KEY")]
     public async Task RunToolResult()
     {

src/AI/ToolFactory.cs

@@ -6,14 +6,37 @@ namespace Devlooped.Extensions.AI;
 /// Creates tools for function calling that can leverage the <see cref="ToolExtensions"/> 
 /// extension methods for locating invocations and their results.
 /// </summary>
-public static class ToolFactory
+public static partial class ToolFactory
 {
     /// <summary>
     /// Invokes <see cref="AIFunctionFactory.Create(Delegate, string?, string?, System.Text.Json.JsonSerializerOptions?)"/> 
-    /// using the method name following the naming convention and serialization options from <see cref="ToolJsonOptions.Default"/>.
+    /// using the method name following the naming convention and serialization options from <see cref="ToolJsonOptions.Default"/> 
+    /// so that <c>FindCalls</c> extension methods on <see cref="ChatResponse"/> can be used.
     /// </summary>
-    public static AIFunction Create(Delegate method)
+    public static AIFunction Create(Delegate method, string? name = default)
         => AIFunctionFactory.Create(method,
-            ToolJsonOptions.Default.PropertyNamingPolicy!.ConvertName(method.Method.Name),
+            name ?? ToolJsonOptions.Default.PropertyNamingPolicy!.ConvertName(SanitizeName(method.Method.Name)),
             serializerOptions: ToolJsonOptions.Default);
+
+    static string SanitizeName(string name)
+    {
+        if (!name.Contains('<'))
+            return name;
+
+        // i.e.: <GetResponsesAsync>g__SetCandidates|0 > SetCandidates
+        var match = AnonymousMethodExpr().Match(name);
+        if (match.Success)
+        {
+            return match.Groups[1].Value;
+        }
+
+        return name
+            .Replace("<", string.Empty)
+            .Replace(">", string.Empty)
+            .Replace("g__", "_")
+            .Replace("|", string.Empty);
+    }
+
+    [System.Text.RegularExpressions.GeneratedRegex(@"__(.+?)\|")]
+    private static partial System.Text.RegularExpressions.Regex AnonymousMethodExpr();
 }