Assert a file exists

Assert that a file exists. To assert all files in a vector exist, see assert_all_files_exist()

Usage

assert_file_exists(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 is does not exist

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 exists, otherwise aborts with the error message specified by msg

Examples

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

try({
assert_file_exists(real_file) # PASSES
assert_file_exists("foo") # Throws Error
assert_file_exists(c(real_file, real_file)) # Throws Error (should use assert_all_files_exist)

})
#> Error in eval(expr, envir) : Failed to find file: foo