Assert a file does not exist — assert_file_does_not_exist • assertions

Assert that a file does not exist. Useful for avoiding overwriting.

Usage

assert_file_does_not_exist(
  x,
  msg = NULL,
  call = rlang::caller_env(),
  arg_name = NULL
)

Arguments

x: Path to a file (string)
msg: A character string containing the error message if file x already exists
call: Only relevant when pooling assertions into multi-assertion helper functions. See cli_abort for details.
arg_name: Advanced use only. Name of the argument passed (default: NULL, will automatically extract arg_name).

Value

invisible(TRUE) if file x does not exist, otherwise aborts with the error message specified by msg

Examples

real_file <- system.file("DESCRIPTION", package = "assertions")

try({
assert_file_does_not_exist("foo") # Passes
assert_file_does_not_exist(real_file) # Throws error
assert_file_does_not_exist(c("foo", "bar")) # Throws Error (single file only)
})
#> Error in eval(expr, envir) : 
#>   File (/home/runner/work/_temp/Library/assertions/DESCRIPTION) already
#> exists