Add ToolResultContentBlock and add TestMessageWithForcedToolIntegrati…

…on (#27)

pkg/anthropic/request.go

@@ -94,6 +94,26 @@ func NewImageContentBlock(mediaType MediaType, base64Data string) ContentBlock {
 	}
 }
 
+// ToolResultContentBlock represents a block of tool result content.
+type ToolResultContentBlock struct {
+	Type      string      `json:"type"`
+	ToolUseID string      `json:"tool_use_id"`
+	Content   interface{} `json:"content"`
+	IsError   bool        `json:"is_error,omitempty"`
+}
+
+func (t ToolResultContentBlock) isContentBlock() {}
+
+// NewToolResultContentBlock creates a new tool result content block with the given parameters.
+func NewToolResultContentBlock(toolUseID string, content interface{}, isError bool) ContentBlock {
+	return ToolResultContentBlock{
+		Type:      "tool_result",
+		ToolUseID: toolUseID,
+		Content:   content,
+		IsError:   isError,
+	}
+}
+
 // ToolChoice specifies the tool preferences for a message request.
 type ToolChoice struct {
 	Type string `json:"type"` // Type of tool choice: "tool", "any", or "auto".

pkg/internal/integration_tests/message_integration_test.go

@@ -58,6 +58,61 @@ func TestMessageWithToolsIntegration(t *testing.T) {
 	}
 }
 
+func TestMessageWithForcedToolIntegration(t *testing.T) {
+	apiKey := os.Getenv("ANTHROPIC_API_KEY")
+	if apiKey == "" {
+		t.Skip("ANTHROPIC_API_KEY environment variable is not set, skipping integration test")
+	}
+
+	client, err := anthropic.NewClient(apiKey)
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+
+	request := &anthropic.MessageRequest{
+		Model:             anthropic.Claude3Opus,
+		MaxTokensToSample: 1024,
+		ToolChoice: &anthropic.ToolChoice{
+			Type: "tool",
+			Name: "get_weather",
+		},
+		Tools: []anthropic.Tool{
+			{
+				Name:        "get_weather",
+				Description: "Get the weather",
+				InputSchema: anthropic.InputSchema{
+					Type: "object",
+					Properties: map[string]anthropic.Property{
+						"city": {Type: "string", Description: "city to get the weather for"},
+						"unit": {Type: "string", Enum: []string{"celsius", "fahrenheit"}, Description: "temperature unit to return"}},
+					Required: []string{"city"},
+				},
+			},
+		},
+		Messages: []anthropic.MessagePartRequest{
+			{
+				Role: "user",
+				Content: []anthropic.ContentBlock{
+					anthropic.NewTextContentBlock("what's the weather in Charleston?"),
+				},
+			},
+		},
+	}
+
+	response, err := client.Message(request)
+	if err != nil {
+		t.Fatalf("Unexpected error: %v", err)
+	}
+
+	if response == nil || len(response.Content) == 0 {
+		t.Errorf("Expected a message response, got none or empty content")
+	}
+
+	if response.StopReason != "tool_use" {
+		t.Errorf("Expected stop reason 'tool_use', got %s", response.StopReason)
+	}
+}
+
 func TestMessageWithImageIntegration(t *testing.T) {
 	apiKey := os.Getenv("ANTHROPIC_API_KEY")
 	if apiKey == "" {