Creating a jpeg preview from Illustrator file that contains slices

I have an adobe add-on which uses the following extendscript  snippet to generate a JPEG preview from an illustrator file.

                var previewBasePath = "/Users/me/Desktop/";

               var previewName = "testexport";

                var type = ExportType.JPEG;

                var saveOptions = new ExportOptionsJPEG();

                saveOptions.artBoardClipping = true;

                saveOptions.qualitySetting = 80;

                saveOptions.horizontalScale = 200;

                saveOptions.verticalScale = 200;

                saveOptions.antiAliasing = true;

                saveOptions.optimization = false;

                var previewPath = previewBasePath + previewName + "_1.jpg";

                var file = new File( previewPath );

                app.activeDocument.exportFile(file, type, saveOptions);

However if the file contains "slices" it always outputs a folder full of files ( one for each slice ) which is not what I want.

If I action export from the FILE > EXPORT > EXPORT AS menu and use all of the default options, I get what I want which is a single jpeg.

Are there extra options for the jpeg export that control this or is there an alternative way to generate the JPEG?

Thanks in advance.