How to use special characters and colours in error messages in R?

Question

I am writting a package in R, and I come around the warnings and error messages. In the book https://style.tidyverse.org/error-messages.html the use of ℹ and ✖ is adviced. However, it doesn't mention how to use the different special character.

On top of that, I would like to know how to colour different elements of the messages provided, such as when loading tidyverse.

Thanks

Answer 1

The vctrs package is using rlang::format_error_bullets

cat(rlang::format_error_bullets(c(i = "Info", x = "Bad")))
#> ℹ Info
#> x Bad

This function is using cli::symbol$info and cli::symbol$cross which are ultimately just "ℹ" and "x"

tidyverse:::tidyverse_attach uses crayon for colours.

cat(paste0(crayon::bold("Attaching packages\n"), crayon::green("Green Text")))