feat: create tool from class that implements ITool

src/AnthropicClient/Models/Tool.cs

@@ -7,6 +7,27 @@ using AnthropicClient.Utils;
 
 namespace AnthropicClient.Models;
 
+/// <summary>
+/// Interface that a class can implement to be used to create a tool.
+/// </summary>
+public interface ITool
+{
+  /// <summary>
+  /// Gets the name of the tool. Should not be null or empty.
+  /// </summary>
+  public string Name { get; }
+
+  /// <summary>
+  /// Gets the description of the tool. Should not be null or empty.
+  /// </summary>
+  public string Description { get; }
+
+  /// <summary>
+  /// Gets the input schema of the tool. Should not be null.
+  /// </summary>
+  public MethodInfo Function { get; }
+}
+
 /// <summary>
 /// Represents a tool that can be used in the chat.
 /// </summary>
@@ -40,6 +61,18 @@ public class Tool
   [JsonIgnore]
   public string DisplayName { get; }
 
+  [JsonConstructor]
+  internal Tool()
+  {
+    var func = () => {};
+
+    Name = string.Empty;
+    Description = string.Empty;
+    InputSchema = [];
+    Function = new AnthropicFunction(func.Method);
+    DisplayName = string.Empty;
+  }
+
   internal Tool(string name, string description, AnthropicFunction function)
   {
     ArgumentValidator.ThrowIfNullOrWhitespace(name, nameof(name));
@@ -58,6 +91,25 @@ public class Tool
     InputSchema = JsonSchemaGenerator.GenerateInputSchema(function);
   }
 
+  /// <summary>
+  /// Creates a tool from a type that implements <see cref="ITool"/>.
+  /// </summary>
+  /// <typeparam name="T">The type that implements <see cref="ITool"/>.</typeparam>
+  /// <exception cref="ArgumentException">Thrown when the name or description of the tool is null or empty.</exception>
+  /// <exception cref="ArgumentNullException">Thrown when the function of the tool is null.</exception>
+  /// <returns>The created tool as instance of <see cref="Tool"/>.</returns>
+  /// <remarks>The implementation of <see cref="ITool"/> must have a parameterless constructor.</remarks>
+  public static Tool CreateFromClass<T>() where T : ITool, new()
+  {
+    var tool = new T();
+
+    ArgumentValidator.ThrowIfNullOrWhitespace(tool.Name, nameof(tool.Name));
+    ArgumentValidator.ThrowIfNullOrWhitespace(tool.Description, nameof(tool.Description));
+    ArgumentValidator.ThrowIfNull(tool.Function, nameof(tool.Function));
+
+    return new Tool(tool.Name, tool.Description, new AnthropicFunction(tool.Function));
+  }
+
   /// <summary>
   /// Creates a tool from a static method.
   /// </summary>

tests/AnthropicClient.Tests/Unit/Models/ToolTests.cs

@@ -246,6 +246,67 @@ public class ToolTests : SerializationTest
       t => t.IgnoringCyclicReferences()
     );
   }
+
+  [Fact]
+  public void CreateFromClass_WhenCalledWithToolWhoseNameIsNull_ItShouldThrowException()
+  {
+    var action = () => Tool.CreateFromClass<ToolWithNullName>();
+
+    action.Should().Throw<ArgumentException>();
+  }
+
+  [Fact]
+  public void CreateFromClass_WhenCalledWithToolWhoseNameIsEmpty_ItShouldThrowException()
+  {
+    var action = () => Tool.CreateFromClass<ToolWithEmptyName>();
+
+    action.Should().Throw<ArgumentException>();
+  }
+
+  [Fact]
+  public void CreateFromClass_WhenCalledWithToolWhoseDescriptionIsNull_ItShouldThrowException()
+  {
+    var action = () => Tool.CreateFromClass<ToolWithNullDescription>();
+
+    action.Should().Throw<ArgumentException>();
+  }
+
+  [Fact]
+  public void CreateFromClass_WhenCalledWithToolWhoseDescriptionIsEmpty_ItShouldThrowException()
+  {
+    var action = () => Tool.CreateFromClass<ToolWithEmptyDescription>();
+
+    action.Should().Throw<ArgumentException>();
+  }
+
+  [Fact]
+  public void CreateFromClass_WhenCalledWithToolWhoseFunctionIsNull_ItShouldThrowException()
+  {
+    var action = () => Tool.CreateFromClass<ToolWithNullFunction>();
+
+    action.Should().Throw<ArgumentNullException>();
+  }
+
+  [Fact]
+  public void CreateFromClass_WhenCalledWithProperTool_ItShouldReturnTool()
+  {
+    var tool = Tool.CreateFromClass<ProperTool>();
+
+    var expectedSchema = new JsonObject()
+    {
+      ["type"] = "object",
+    };
+
+    tool.Name.Should().Be("Name");
+    tool.DisplayName.Should().Be("Name");
+    tool.Description.Should().Be("Description");
+    tool.Function.Method.Name.Should().Be(nameof(ProperTool.GetWeather));
+    tool.Function.Instance.Should().BeNull();
+    tool.InputSchema.Should().BeEquivalentTo(
+      expectedSchema,
+      t => t.IgnoringCyclicReferences()
+    );
+  }
 }
 
 class TestClass
@@ -255,3 +316,82 @@ class TestClass
   public static bool TestStaticMethod() => true;
   public bool TestInstanceMethod() => _result;
 }
+
+class ProperTool : ITool
+{
+  public string Name => "Name";
+
+  public string Description { get; } = "Description";
+
+  public MethodInfo Function => typeof(ProperTool).GetMethod(nameof(GetWeather))!;
+
+  public static string GetWeather()
+  {
+    return "Sunny";
+  }
+}
+
+class ToolWithNullName : ITool
+{
+  public string Name => null!;
+
+  public string Description { get; } = "Description";
+
+  public MethodInfo Function => typeof(ToolWithNullName).GetMethod(nameof(Tool))!;
+
+  public static string GetWeather()
+  {
+    return "Sunny";
+  }
+}
+
+class ToolWithEmptyName : ITool
+{
+  public string Name => string.Empty;
+
+  public string Description { get; } = "Description";
+
+  public MethodInfo Function => typeof(ToolWithEmptyName).GetMethod(nameof(Tool))!;
+
+  public static string GetWeather()
+  {
+    return "Sunny";
+  }
+}
+
+class ToolWithNullDescription : ITool
+{
+  public string Name => "Name";
+
+  public string Description => null!;
+
+  public MethodInfo Function => typeof(ToolWithNullDescription).GetMethod(nameof(Tool))!;
+
+  public static string GetWeather()
+  {
+    return "Sunny";
+  }
+}
+
+class ToolWithEmptyDescription : ITool
+{
+  public string Name => "Name";
+
+  public string Description => string.Empty;
+
+  public MethodInfo Function => typeof(ToolWithEmptyDescription).GetMethod(nameof(Tool))!;
+
+  public static string GetWeather()
+  {
+    return "Sunny";
+  }
+}
+
+class ToolWithNullFunction : ITool
+{
+  public string Name => "Name";
+
+  public string Description => "Description";
+
+  public MethodInfo Function => null!;
+}