count_fields does not interpret single line string wrapped with I() as literal data

[mrainers]

The manual of count_fields {readr} decribe the file parameter as following:

To be recognised as literal data, the input must be either wrapped with I(), be a string containing at least one new line, or be a vector containing at least one string with a new line.

However, wrapping the string with I() doesn't seem to have any effekt. If file is a single string it is interpreted as a file name even when wrapped with I() instead of literal data.

data <- c('"foo","bar","baz"')
count_fields(I(data), tokenizer = tokenizer_csv())

Error: '"foo","bar","baz"' does not exist in current working directory 

Expected result: 3

Workaround: temporarly attach a new line.

data <- c('"foo","bar","baz"')
count_fields(paste0(data, "\n"), tokenizer = tokenizer_csv())

readr version: 2.1.5