Fix literal \", nil\" in handleStagingRemove error format string

connection.go

@@ -587,7 +587,7 @@ func (c *conn) handleStagingRemove(ctx context.Context, presignedUrl string, hea
 	content, err := io.ReadAll(res.Body)
 
 	if err != nil || !Succeeded(res) {
-		return dbsqlerrint.NewDriverError(ctx, fmt.Sprintf("staging operation over HTTP was unsuccessful: %d-%s, nil", res.StatusCode, content), nil)
+		return dbsqlerrint.NewDriverError(ctx, fmt.Sprintf("staging operation over HTTP was unsuccessful: %d-%s", res.StatusCode, content), nil)
 	}
 
 	return nil

staging_test.go

@@ -1,11 +1,29 @@
 package dbsql
 
 import (
+	"context"
+	"net/http"
+	"net/http/httptest"
 	"testing"
 
+	"github.com/databricks/databricks-sql-go/internal/config"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
+func TestHandleStagingRemoveHTTPError(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusForbidden)
+		w.Write([]byte("Access Denied"))
+	}))
+	defer server.Close()
+
+	c := &conn{cfg: config.WithDefaults()}
+	err := c.handleStagingRemove(context.Background(), server.URL, map[string]string{})
+	require.NotNil(t, err)
+	assert.NotContains(t, err.Error(), ", nil", "error message should not contain literal \", nil\"")
+}
+
 func TestPathAllowed(t *testing.T) {
 	t.Run("Should not allow paths that don't share directory", func(t *testing.T) {
 		stagingAllowedLocalPath := []string{"/var/www/html"}