R Lifecycle skill

R Package Lifecycle Management

Manage function and argument lifecycle using tidyverse conventions and the lifecycle package.

Setup

Check if lifecycle is configured by looking for lifecycle-*.svg files in man/figures/.

If not configured, run:

usethis::use_lifecycle()

This:

• Adds lifecycle to Imports in DESCRIPTION
• Adds @importFrom lifecycle deprecated to the package documentation file
• Copies badge SVGs to man/figures/

Lifecycle Badges

Insert badges in roxygen2 documentation:

#' @description
#' `r lifecycle::badge("experimental")`
#' `r lifecycle::badge("deprecated")`
#' `r lifecycle::badge("superseded")`

For arguments:

#' @param old_arg `r lifecycle::badge("deprecated")` Use `new_arg` instead.

Only badge functions/arguments whose stage differs from the package's overall stage.

Deprecating a Function

1. Add badge and explanation to @description:

#' Do something
#'
#' @description
#' `r lifecycle::badge("deprecated")`
#'
#' `old_fun()` was deprecated in mypkg 1.0.0. Use [new_fun()] instead.
#' @keywords internal

2. Add deprecate_warn() as first line of function body:

old_fun <- function(x) {

lifecycle::deprecate_warn("1.0.0", "old_fun()", "new_fun()")
new_fun(x)
}

3. Show migration in examples:

#' @examples
#' old_fun(x)
#' # ->
#' new_fun(x)

Deprecation Functions

Function	When to Use
deprecate_soft()	First stage; warns only direct users and during tests
deprecate_warn()	Standard deprecation; warns once per 8 hours
deprecate_stop()	Final stage before removal; errors with helpful message

Deprecation workflow for major releases:

1. Search deprecate_stop() - consider removing function entirely
2. Replace deprecate_warn() with deprecate_stop()
3. Replace deprecate_soft() with deprecate_warn()

Renaming a Function

Move implementation to new name, call from old name with deprecation:

#' @description
#' `r lifecycle::badge("deprecated")`
#'
#' `add_two()` was renamed to `number_add()` for API consistency.
#' @keywords internal
#' @export
add_two <- function(x, y) {
lifecycle::deprecate_warn("1.0.0", "add_two()", "number_add()")
number_add(x, y)
}

#' Add two numbers
#' @export
number_add <- function(x, y) {
x + y
}

Deprecating an Argument

Use deprecated() as default value with is_present() check:

#' @param path `r lifecycle::badge("deprecated")` Use `file` instead.
write_file <- function(x, file, path = deprecated()) {
  if (lifecycle::is_present(path)) {
    lifecycle::deprecate_warn("1.4.0", "write_file(path)", "write_file(file)")
    file <- path
  }
  # ... rest of function
}

Renaming an Argument

add_two <- function(x, y, na_rm = TRUE, na.rm = deprecated()) {
  if (lifecycle::is_present(na.rm)) {
    lifecycle::deprecate_warn("1.0.0", "add_two(na.rm)", "add_two(na_rm)")
    na_rm <- na.rm
  }
  sum(x, y, na.rm = na_rm)
}

Superseding a Function

For functions with better alternatives that shouldn't be removed:

#' Gather columns into key-value pairs
#'
#' @description
#' `r lifecycle::badge("superseded")`
#'
#' Development on `gather()` is complete. For new code, use [pivot_longer()].
#'
#' `df %>% gather("key", "value", x, y, z)` is equivalent to
#' `df %>% pivot_longer(c(x, y, z), names_to = "key", values_to = "value")`.

No warning needed - just document the preferred alternative.

Marking as Experimental

#' @description
#' `r lifecycle::badge("experimental")`
cool_function <- function() {
  lifecycle::signal_stage("experimental", "cool_function()")
  # ...
}

Testing Deprecations

Test that deprecated functions work and warn appropriately:

test_that("old_fun is deprecated", {
  expect_snapshot({
    x <- old_fun(1)
    expect_equal(x, expected_value)
  })
})

Suppress warnings in existing tests:

test_that("old_fun returns correct value", {
  withr::local_options(lifecycle_verbosity = "quiet")
  expect_equal(old_fun(1), expected_value)
})

Deprecation Helpers

For deprecations affecting many functions (e.g., removing a common argument), create an internal helper:

warn_for_verbose <- function(
  verbose = TRUE,
  env = rlang::caller_env(),
  user_env = rlang::caller_env(2)
) {
  if (!lifecycle::is_present(verbose) || isTRUE(verbose)) {
    return(invisible())
  }

  lifecycle::deprecate_warn(
    when = "2.0.0",
    what = I("The `verbose` argument"),
    details = c(
      "Set `options(mypkg_quiet = TRUE)` to suppress messages.",
      "The `verbose` argument will be removed in a future release."
    ),
    user_env = user_env
  )

  invisible()
}

Then use in affected functions:

my_function <- function(..., verbose = deprecated()) {
  warn_for_verbose(verbose)
  # ...
}

Custom Deprecation Messages

For non-standard deprecations, use I() to wrap custom text:

lifecycle::deprecate_warn(
  when = "1.0.0",
  what = I('Setting option "pkg.opt" to "foo"'),
  with = I('"pkg.new_opt"')
)

The what fragment must work with "was deprecated in..." appended.

Reference

See references/lifecycle-stages.md for detailed stage definitions and transitions.