first commit

core/mcp/utils_test.go

@@ -0,0 +1,171 @@
+package mcp
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/mark3labs/mcp-go/mcp"
+	"github.com/maximhq/bifrost/core/schemas"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestConvertMCPToolToBifrostSchema_EmptyParameters tests that tools with no parameters
+// get an empty properties map instead of nil, which is required by some providers like OpenAI
+func TestConvertMCPToolToBifrostSchema_EmptyParameters(t *testing.T) {
+	// Create a tool with no parameters (like return_special_chars or return_null)
+	mcpTool := &mcp.Tool{
+		Name:        "test_tool_no_params",
+		Description: "A test tool with no parameters",
+		InputSchema: mcp.ToolInputSchema{
+			Type:       "object",
+			Properties: map[string]interface{}{}, // Empty properties
+			Required:   []string{},
+		},
+	}
+
+	// Convert the tool
+	bifrostTool := convertMCPToolToBifrostSchema(mcpTool, defaultLogger)
+
+	// Verify the function was created
+	if bifrostTool.Function == nil {
+		t.Fatal("Function should not be nil")
+	}
+
+	// Verify parameters were created
+	if bifrostTool.Function.Parameters == nil {
+		t.Fatal("Parameters should not be nil")
+	}
+
+	// Verify properties is not nil (this is the key fix)
+	if bifrostTool.Function.Parameters.Properties == nil {
+		t.Error("Properties should not be nil for object type, even if empty")
+	}
+
+	// Verify it's an empty map
+	if bifrostTool.Function.Parameters.Properties != nil && bifrostTool.Function.Parameters.Properties.Len() != 0 {
+		t.Errorf("Expected empty properties map, got %d properties", bifrostTool.Function.Parameters.Properties.Len())
+	}
+
+	// Verify the type is preserved
+	if bifrostTool.Function.Parameters.Type != "object" {
+		t.Errorf("Expected type 'object', got '%s'", bifrostTool.Function.Parameters.Type)
+	}
+}
+
+// TestConvertMCPToolToBifrostSchema_WithAnnotations tests that MCP tool annotations
+// are preserved on ChatTool.Annotations (not ChatToolFunction) and are absent from JSON.
+func TestConvertMCPToolToBifrostSchema_WithAnnotations(t *testing.T) {
+	readOnly := true
+	destructive := false
+
+	mcpTool := &mcp.Tool{
+		Name:        "read_resource",
+		Description: "Reads a resource",
+		InputSchema: mcp.ToolInputSchema{
+			Type:       "object",
+			Properties: map[string]interface{}{},
+		},
+		Annotations: mcp.ToolAnnotation{
+			Title:           "Resource Reader",
+			ReadOnlyHint:    &readOnly,
+			DestructiveHint: &destructive,
+			IdempotentHint:  schemas.Ptr(true),
+		},
+	}
+
+	bifrostTool := convertMCPToolToBifrostSchema(mcpTool, defaultLogger)
+
+	// Annotations must be on ChatTool, not buried in Function
+	require.NotNil(t, bifrostTool.Annotations, "Annotations should be set on ChatTool")
+	assert.Equal(t, "Resource Reader", bifrostTool.Annotations.Title)
+	require.NotNil(t, bifrostTool.Annotations.ReadOnlyHint)
+	assert.True(t, *bifrostTool.Annotations.ReadOnlyHint)
+	require.NotNil(t, bifrostTool.Annotations.DestructiveHint)
+	assert.False(t, *bifrostTool.Annotations.DestructiveHint)
+	require.NotNil(t, bifrostTool.Annotations.IdempotentHint)
+	assert.True(t, *bifrostTool.Annotations.IdempotentHint)
+	assert.Nil(t, bifrostTool.Annotations.OpenWorldHint)
+
+	// The JSON sent to providers must not contain annotations
+	toolJSON, err := json.Marshal(bifrostTool)
+	require.NoError(t, err)
+	s := string(toolJSON)
+	assert.NotContains(t, s, "annotations", "annotations must be absent from provider JSON")
+	assert.NotContains(t, s, "readOnlyHint", "readOnlyHint must be absent from provider JSON")
+	assert.NotContains(t, s, "Resource Reader", "annotation title must be absent from provider JSON")
+}
+
+// TestConvertMCPToolToBifrostSchema_NilAnnotationsWhenAllZero verifies the nil guard:
+// when all annotation fields are zero-valued, ChatTool.Annotations must remain nil.
+func TestConvertMCPToolToBifrostSchema_NilAnnotationsWhenAllZero(t *testing.T) {
+	mcpTool := &mcp.Tool{
+		Name:        "no_hints_tool",
+		Description: "A tool with no annotation hints",
+		InputSchema: mcp.ToolInputSchema{
+			Type:       "object",
+			Properties: map[string]interface{}{},
+		},
+		Annotations: mcp.ToolAnnotation{}, // All zero values — Title empty, all hints nil
+	}
+
+	bifrostTool := convertMCPToolToBifrostSchema(mcpTool, defaultLogger)
+
+	assert.Nil(t, bifrostTool.Annotations,
+		"Annotations should be nil when all MCP annotation fields are zero")
+}
+
+// TestConvertMCPToolToBifrostSchema_WithParameters tests the normal case with parameters
+func TestConvertMCPToolToBifrostSchema_WithParameters(t *testing.T) {
+	// Create a tool with parameters
+	mcpTool := &mcp.Tool{
+		Name:        "test_tool_with_params",
+		Description: "A test tool with parameters",
+		InputSchema: mcp.ToolInputSchema{
+			Type: "object",
+			Properties: map[string]interface{}{
+				"param1": map[string]interface{}{
+					"type":        "string",
+					"description": "A string parameter",
+				},
+				"param2": map[string]interface{}{
+					"type":        "number",
+					"description": "A number parameter",
+				},
+			},
+			Required: []string{"param1"},
+		},
+	}
+
+	// Convert the tool
+	bifrostTool := convertMCPToolToBifrostSchema(mcpTool, defaultLogger)
+
+	// Verify the function was created
+	if bifrostTool.Function == nil {
+		t.Fatal("Function should not be nil")
+	}
+
+	// Verify parameters were created
+	if bifrostTool.Function.Parameters == nil {
+		t.Fatal("Parameters should not be nil")
+	}
+
+	// Verify properties is not nil
+	if bifrostTool.Function.Parameters.Properties == nil {
+		t.Fatal("Properties should not be nil")
+	}
+
+	// Verify the correct number of properties
+	if bifrostTool.Function.Parameters.Properties.Len() != 2 {
+		t.Errorf("Expected 2 properties, got %d", bifrostTool.Function.Parameters.Properties.Len())
+	}
+
+	// Verify required fields
+	if len(bifrostTool.Function.Parameters.Required) != 1 {
+		t.Errorf("Expected 1 required field, got %d", len(bifrostTool.Function.Parameters.Required))
+	}
+
+	if bifrostTool.Function.Parameters.Required[0] != "param1" {
+		t.Errorf("Expected required field 'param1', got '%s'", bifrostTool.Function.Parameters.Required[0])
+	}
+}