expect_null_linter: Require usage of 'expect_null' for checking 'NULL'

In lintr: A 'Linter' for R Code

Require usage of expect_null for checking NULL

Description

Require usage of expect_null(x) over expect_equal(x, NULL) and similar usages.

Usage

expect_null_linter()

Details

testthat::expect_null() exists specifically for testing for NULL objects. testthat::expect_equal(), testthat::expect_identical(), and testthat::expect_true() can also be used for such tests, but it is better to use the tailored function instead.

Tags

best_practices, package_development, pkg_testthat

See Also

linters for a complete list of linters available in lintr.

Examples

# will produce lints
lint(
  text = "expect_equal(x, NULL)",
  linters = expect_null_linter()
)

lint(
  text = "expect_identical(x, NULL)",
  linters = expect_null_linter()
)

lint(
  text = "expect_true(is.null(x))",
  linters = expect_null_linter()
)


# okay
lint(
  text = "expect_null(x)",
  linters = expect_null_linter()
)

lintr documentation built on April 12, 2025, 1:42 a.m.