expect_deprecated: Does expression produce lifecycle warnings or errors?

In lifecycle: Manage the Life Cycle of your Package Functions

Does expression produce lifecycle warnings or errors?

Description

These functions are equivalent to testthat::expect_warning() and testthat::expect_error() but check specifically for lifecycle warnings or errors.

To test whether a deprecated feature still works without causing a deprecation warning, set the lifecycle_verbosity option to "quiet".

test_that("feature still works", {
  withr::local_options(lifecycle_verbosity = "quiet")
  expect_true(my_deprecated_function())
})

Usage

expect_deprecated(expr, regexp = NULL, ...)

expect_defunct(expr)

Arguments

expr	Expression that should produce a lifecycle warning or error.
regexp	Optional regular expression matched against the expected warning message.
...	Arguments passed on to expect_match fixed If TRUE, treats regexp as a string to be matched exactly (not a regular expressions). Overrides perl. perl logical. Should Perl-compatible regexps be used?

Details

expect_deprecated() sets the lifecycle_verbosity option to "warning" to enforce deprecation warnings which are otherwise only shown once per session.

lifecycle documentation built on Jan. 8, 2026, 9:08 a.m.