---

name: lifecycle description: > Guidance for managing R package lifecycle according to tidyverse principles using the lifecycle package. Use when: (1) Setting up lifecycle infrastructure in a package, (2) Deprecating functions or arguments, (3) Renaming functions or arguments, (4) Superseding functions, (5) Marking functions as experimental, (6) Understanding lifecycle stages (stable, experimental, deprecated, superseded), or (7) Writing deprecation helpers for complex scenarios.

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:

Copyusethis::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:

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#' `r lifecycle::badge("superseded")`

For arguments:

Copy#' @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:

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

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

Copyold_fun <- function(x) {

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

1. Show migration in examples:

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

Deprecation Functions

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:

Copy#' @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:

Copy#' @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

Copyadd_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:

Copy#' 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

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

Testing Deprecations

Test that deprecated functions work and warn appropriately:

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

Suppress warnings in existing tests:

Copytest_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:

Copywarn_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:

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

Custom Deprecation Messages

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

Copylifecycle::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.