library(future)
library(sparklyr)

sc <- spark_connect(master = "local", spark_version = "2.3.0")

if(file.exists("source")) unlink("source", TRUE)
if(file.exists("source-out")) unlink("source-out", TRUE)

stream_generate_test(iterations = 10)
read_folder <- stream_read_csv(sc, "source")
write_output <- stream_write_csv(read_folder, "source-out")
invisible(future(stream_generate_test(interval = 0.1)))

stream_view(write_output)