write_delim clearing (non-empty) files with append = TRUE

[cljacobs]

As per the title, the write_delim function will delete all the previous contents of a file, even if append = TRUE if provided an empty data.frame (tibble, etc) as the primary argument.

readr version: 2.1.2

A minimal example, below.

library(readr)
cat("some text in a file\n",file="empty.txt")
write_tsv(data.frame(),file="empty.txt",append=TRUE)
read_lines("empty.txt")
# character(0)

compare to:

library(readr)
cat("some text in a file\n",file="nonempty.txt")
write_tsv(data.frame(a=1:3,b=LETTERS[1:3]),file="nonempty.txt",append=TRUE)
read_lines("nonempty.txt")
# [1] "some text in a file"     "1\tA"    "2\tB"    "3\tC" 

or:

library(readr)
cat("some text in a file\n",file="nonempty.txt")
write.table(data.frame(),file="test.txt",append=TRUE,col.names=FALSE)
read_lines("nonempty.txt")
# [1] "some text in a file"