tests/testthat/test-equals_na_linter.R

In lintr: A 'Linter' for R Code

test_that("equals_na_linter skips allowed usages", {
  linter <- equals_na_linter()

  expect_lint("blah", NULL, linter)
  expect_lint("  blah", NULL, linter)
  expect_lint("  blah", NULL, linter)
  expect_lint("x=NA", NULL, linter)
  expect_lint("x = NaN", NULL, linter)
  expect_lint("x = NA_real_", NULL, linter)
  expect_lint("is.na(x)", NULL, linter)
  expect_lint("is.nan(x)", NULL, linter)
  expect_lint("x[!is.na(x)]", NULL, linter)

  # equals_na_linter should ignore strings and comments
  expect_lint("is.na(x) # do not flag x == NA if inside a comment", NULL, linter)
  expect_lint("lint_msg <- 'do not flag x == NA if inside a string'", NULL, linter)

  # nested NAs are okay
  expect_lint("x==f(1, ignore = NA)", NULL, linter)

  # this should be covered by any_is_na_linter()
  expect_lint("NA %in% x", NULL, linter)
})

skip_if_not_installed("tibble")
patrick::with_parameters_test_that(
  "equals_na_linter blocks disallowed usages for all combinations of operators and types of NAs",
  expect_lint(
    paste("x", operation, type_na),
    rex::rex("Use is.na for comparisons to NA (not == or != or %in%)"),
    equals_na_linter()
  ),
  .cases = tibble::tribble(
    ~.test_name,                 ~operation, ~type_na,
    "equality, logical NA",      "==",       "NA",
    "equality, integer NA",      "==",       "NA_integer_",
    "equality, real NA",         "==",       "NA_real_",
    "equality, complex NA",      "==",       "NA_complex_",
    "equality, character NA",    "==",       "NA_character_",
    "containment, logical NA",   "%in%",     "NA",
    "containment, integer NA",   "%in%",     "NA_integer_",
    "containment, real NA",      "%in%",     "NA_real_",
    "containment, complex NA",   "%in%",     "NA_complex_",
    "containment, character NA", "%in%",     "NA_character_",
    "inequality, logical NA",    "!=",       "NA",
    "inequality, integer NA",    "!=",       "NA_integer_",
    "inequality, real NA",       "!=",       "NA_real_",
    "inequality, complex NA",    "!=",       "NA_complex_",
    "inequality, character NA",  "!=",       "NA_character_"
  )
)

test_that("equals_na_linter blocks disallowed usages in edge cases", {
  linter <- equals_na_linter()
  lint_msg <- rex::rex("Use is.na for comparisons to NA (not == or != or %in%)")

  # missing spaces around operators
  expect_lint("x==NA", list(message = lint_msg, line_number = 1L, column_number = 1L), linter)
  expect_lint("x!=NA", list(message = lint_msg, line_number = 1L, column_number = 1L), linter)

  # order doesn't matter
  expect_lint("NA == x", list(message = lint_msg, line_number = 1L, column_number = 1L), linter)

  # correct line number for multiline code
  expect_lint("x ==\nNA", list(line_number = 1L, column_number = 1L, ranges = list(c(1L, 4L))), linter)
})