It's basically ggsave() with some addons

gg_export()

# This function exports plots. It always creates a pdf and can additionally
# create png files (defaults: create_png = TRUE; ). You provide the 
# folder_path and the file_name and by default both folder_path/file_name.pdf 
# and folder_path/file_name.png will be created.
#
# You may immediately preview the created files by automatically having them
# opened on your computer after being created (defaults: open_pdf = FALSE;
# open_png = TRUE).
#
# The pdf is exported via ggplot2::ggsave(), but the png is not! Instead,
# the png is actually created by reimporting the exported pdf and exporting
# it via png::writePNG(). This hack is supposed to ensure having the same scales
# and (font) sizes in both files. 

# if necessary: install necessary packages
if (!require("png")) install.packages("png")
if (!require("ggplot2")) install.packages("ggplot2")
if (!require("pdftools")) install.packages("pdftools")
if (!require("ggplotify")) install.packages("ggplotify")


gg_export <-
  function(plot_obj = NULL,
           folder_path = NULL,
           file_name = NULL,
           width_cm = 16,
           height_cm = 10,
           create_pdf = FALSE,
           create_png = TRUE,
           open_pdf = FALSE,
           open_png = TRUE
           ) {
    
    # for a manually curated list of non-ggplot2 plot types,
    # the object is converted to make things work:
    others <- c(
      "trellis"  # {desplot}
      )
    
    if (class(plot_obj)[1] %in% others) { 
      plot_obj <- ggplotify::as.ggplot(plot_obj)
    }
    
    # export pdf
    pdf_path  <- paste0(folder_path, "/", file_name, ".pdf")
      
    ggplot2::ggsave(
      filename = pdf_path,
      plot = plot_obj,
      width = width_cm,
      height = height_cm,
      units = "cm",
      scale = 1,
      device = cairo_pdf
    )
    
    # export png
    if (create_png) {
      png_path  <- paste0(folder_path, "/", file_name, ".png")
      
      bitmap <- pdftools::pdf_render_page(pdf_path, page = 1, dpi = 300)
      png::writePNG(bitmap, png_path)
    }
    
    if (!create_pdf) {
      file.remove(pdf_path)
    }
   
    # open pdf
    if (open_pdf) {
      system(paste0('open "', pdf_path, '"'))
    }
     
    # open png
    if (open_png) {
      system(paste0('open "', png_path, '"'))
    }  

  }