Equality check with NA linter

Check for x == NA, x != NA and x %in% NA. Such usage is almost surely incorrect – checks for missing values should be done with is.na().

Usage

equals_na_linter()

See also

linters for a complete list of linters available in lintr.

Tags

common_mistakes, correctness, default, robustness

Examples

# will produce lints
lint(
  text = "x == NA",
  linters = equals_na_linter()
)
#> <text>:1:1: warning: [equals_na_linter] Use is.na() instead of x == NA
#> x == NA
#> ^~~~~~~

lint(
  text = "x != NA",
  linters = equals_na_linter()
)
#> <text>:1:1: warning: [equals_na_linter] Use is.na() instead of x != NA
#> x != NA
#> ^~~~~~~

lint(
  text = "x %in% NA",
  linters = equals_na_linter()
)
#> <text>:1:1: warning: [equals_na_linter] Use is.na() instead of x %in% NA
#> x %in% NA
#> ^~~~~~~~~

# okay
lint(
  text = "is.na(x)",
  linters = equals_na_linter()
)
#> ℹ No lints found.

lint(
  text = "!is.na(x)",
  linters = equals_na_linter()
)
#> ℹ No lints found.