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()
)
#> ::warning file=<text>,line=1,col=1::file=<text>,line=1,col=1,[equals_na_linter] Use is.na for comparisons to NA (not == or != or %in%)

lint(
  text = "x != NA",
  linters = equals_na_linter()
)
#> ::warning file=<text>,line=1,col=1::file=<text>,line=1,col=1,[equals_na_linter] Use is.na for comparisons to NA (not == or != or %in%)

lint(
  text = "x %in% NA",
  linters = equals_na_linter()
)
#> ::warning file=<text>,line=1,col=1::file=<text>,line=1,col=1,[equals_na_linter] Use is.na for comparisons to NA (not == or != or %in%)

# okay
lint(
  text = "is.na(x)",
  linters = equals_na_linter()
)

lint(
  text = "!is.na(x)",
  linters = equals_na_linter()
)