test(tools): more robust multiple tool call handling

backend/agents/client/tools.go

@@ -20,26 +20,38 @@ type ToolsHandlers struct {
 	handlers *map[string]ToolHandler
 }
 
-func (handler ToolsHandlers) Handle(info ToolHandlerInfo, toolCallMessage AgentAssistantToolCall) (AgentTextMessage, error) {
+var NoToolCallError = errors.New("An assistant tool call with no tool calls was provided.")
-	fnName := toolCallMessage.ToolCalls[0].Function.Name
+
-	arguments := toolCallMessage.ToolCalls[0].Function.Arguments
+func (handler ToolsHandlers) Handle(info ToolHandlerInfo, toolCallMessage AgentAssistantToolCall) ([]AgentTextMessage, error) {
+	if len(toolCallMessage.ToolCalls) == 0 {
+		return []AgentTextMessage{}, NoToolCallError
+	}
+
+	responses := make([]AgentTextMessage, len(toolCallMessage.ToolCalls))
+
+	for i, toolCall := range toolCallMessage.ToolCalls {
+		fnName := toolCall.Function.Name
+		arguments := toolCall.Function.Arguments
 
 		fnHandler, exists := (*handler.handlers)[fnName]
 		if !exists {
-		return AgentTextMessage{}, errors.New("Could not find tool with this name.")
+			return []AgentTextMessage{}, errors.New("Could not find tool with this name.")
 		}
 
 		res, err := fnHandler.Fn(info, arguments, toolCallMessage.ToolCalls[0])
 		if err != nil {
-		return AgentTextMessage{}, err
+			return []AgentTextMessage{}, err
 		}
 
-	return AgentTextMessage{
+		responses[i] = AgentTextMessage{
 			Role:       "tool",
 			Name:       fnName,
 			Content:    res,
-		ToolCallId: toolCallMessage.ToolCalls[0].Id,
+			ToolCallId: toolCall.Id,
-	}, nil
+		}
+	}
+
+	return responses, nil
 }
 
 func (handler ToolsHandlers) AddTool(name string, fn func(info ToolHandlerInfo, args string, call ToolCall) (any, error)) {

backend/agents/client/tools_test.go

@@ -4,21 +4,30 @@ import (
 	"testing"
 
 	"github.com/google/uuid"
-	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/suite"
 )
 
-func TestSingleToolCall(t *testing.T) {
+type ToolTestSuite struct {
-	assert := assert.New(t)
+	suite.Suite
 
-	tools := ToolsHandlers{
+	handler ToolsHandlers
+}
+
+func (suite *ToolTestSuite) SetupTest() {
+	suite.handler = ToolsHandlers{
 		handlers: &map[string]ToolHandler{},
 	}
 
-	tools.AddTool("a", func(info ToolHandlerInfo, args string, call ToolCall) (any, error) {
+	suite.handler.AddTool("a", func(info ToolHandlerInfo, args string, call ToolCall) (any, error) {
 		return true, nil
 	})
+}
 
-	response, err := tools.Handle(
+func (suite *ToolTestSuite) TestSingleToolCall() {
+	assert := suite.Assert()
+	require := suite.Require()
+
+	response, err := suite.handler.Handle(
 		ToolHandlerInfo{
 			UserId:  uuid.Nil,
 			ImageId: uuid.Nil,
@@ -36,12 +45,83 @@ func TestSingleToolCall(t *testing.T) {
 			}},
 		})
 
-	if assert.NoError(err, "Tool call shouldnt return an error") {
+	require.NoError(err, "Tool call shouldnt return an error")
-		assert.EqualValues(response, AgentTextMessage{
+
+	assert.EqualValues(response, []AgentTextMessage{{
 		Role:       "tool",
 		Content:    "true",
 		ToolCallId: "1",
 		Name:       "a",
+	}})
+}
+
+func (suite *ToolTestSuite) TestEmptyCall() {
+	require := suite.Require()
+
+	_, err := suite.handler.Handle(
+		ToolHandlerInfo{
+			UserId:  uuid.Nil,
+			ImageId: uuid.Nil,
+		},
+		AgentAssistantToolCall{
+			Role:      "assistant",
+			Content:   "",
+			ToolCalls: []ToolCall{},
+		})
+
+	require.ErrorIs(err, NoToolCallError)
+}
+
+func (suite *ToolTestSuite) TestMultipleToolCalls() {
+	assert := suite.Assert()
+	require := suite.Require()
+
+	response, err := suite.handler.Handle(
+		ToolHandlerInfo{
+			UserId:  uuid.Nil,
+			ImageId: uuid.Nil,
+		},
+		AgentAssistantToolCall{
+			Role:    "assistant",
+			Content: "",
+			ToolCalls: []ToolCall{
+				{
+					Index: 0,
+					Id:    "1",
+					Function: FunctionCall{
+						Name:      "a",
+						Arguments: "",
+					},
+				},
+				{
+					Index: 1,
+					Id:    "2",
+					Function: FunctionCall{
+						Name:      "a",
+						Arguments: "",
+					},
+				},
+			},
+		})
+
+	require.NoError(err, "Tool call shouldnt return an error")
+
+	assert.EqualValues(response, []AgentTextMessage{
+		{
+			Role:       "tool",
+			Content:    "true",
+			ToolCallId: "1",
+			Name:       "a",
+		},
+		{
+			Role:       "tool",
+			Content:    "true",
+			ToolCallId: "2",
+			Name:       "a",
+		},
 	})
 }
+
+func TestToolSuite(t *testing.T) {
+	suite.Run(t, &ToolTestSuite{})
 }