Take a look at the switch call. That's basically it. Returns an appropriate function or throws an error if wasn't able to find one.
cloud_guess_write_fun(file)A writing function.
Path to a file relative to project folder root. Can contain only letters, digits, '-', '_', '.', spaces and '/' symbols.
Here's how we identify a writing function based on file extension
.csv: readr::write_csv
.json: jsonlite::write_json
.rds: base::saveRDS
.xls: writexl::write_xlsx
.xlsx: writexl::write_xlsx
.sav: haven::write_sav
.xml: xml2::write_xml