package.md
In usethis: Automate Package and Project Setup

use_package() guides new packages but not pre-existing ones

Code
  use_package("withr")
Message
  v Adding 'withr' to Imports field in DESCRIPTION
  * Refer to functions with `withr::fun()`
Code
  use_package("withr")
  use_package("withr", "Suggests")
Condition
  Warning:
  Package 'withr' is already listed in 'Imports' in DESCRIPTION, no change made.

use_package() handles R versions with aplomb

Code
  use_package("R")
Condition
  Error:
  ! Set `type = "Depends"` when specifying an R version

Code
  use_package("R", type = "Depends")
Condition
  Error:
  ! Specify `min_version` when `package = "R"`

Code
  use_package("R", type = "Depends", min_version = "3.6")
Message
  v Adding 'R' to Depends field in DESCRIPTION

Code
  use_package("R", type = "Depends", min_version = TRUE)
Message
  v Increasing 'R' version to '>= 4.1' in DESCRIPTION

use_package(type = 'Suggests') guidance w/o and w/ rlang

Code
  use_package("withr", "Suggests")
Message
  v Adding 'withr' to Suggests field in DESCRIPTION
  * Use `requireNamespace("withr", quietly = TRUE)` to test if package is installed
  * Then directly refer to functions with `withr::fun()`

Code
  use_package("purrr", "Suggests")
Message
  v Adding 'purrr' to Suggests field in DESCRIPTION
  * In your package code, use `rlang::is_installed("purrr")` or `rlang::check_installed("purrr")` to test if purrr is installed
  * Then directly refer to functions with `purrr::fun()`