tests/testthat/test-expect_lint.R

In lintr: A 'Linter' for R Code

# testthat's expect_success() and expect_failure() can only handle the first expectation and are
# thus less than ideal to test expect_lint(), which can process multiple lints. If you want to test
# for failure, always put the lint check or lint field that must fail first.

linter <- assignment_linter()
lint_msg <- "Use <-, not ="

test_that("no checks", {
  expect_success(expect_lint("a", NULL, linter))
  expect_success(expect_lint("a=1", NULL, list()))
  expect_failure(expect_lint("a=1", NULL, linter))
})

test_that("single check", {
  expect_failure(expect_lint(character(), lint_msg, linter))
  expect_failure(expect_lint("", lint_msg, linter))

  expect_success(expect_lint(content = "a=1", checks = lint_msg, linters = linter))
  expect_success(expect_lint("a=1", lint_msg, linter))
  expect_failure(expect_lint("a=1", "asdf", linter))
  expect_success(expect_lint("a=1", c(message = lint_msg), linter))
  expect_failure(expect_lint("a=1", c(message = NULL), linter))
  expect_success(expect_lint("a=1", c(message = lint_msg, line_number = 1L), linter))
  expect_failure(expect_lint("a=1", c(line_number = 2L, message = lint_msg), linter))

  expect_error(expect_lint("a=1", c(message = lint_msg, lineXXX = 1L), linter), "invalid field")

  expect_failure(expect_lint("foo ()", list(ranges = list(c(2L, 2L))), function_left_parentheses_linter()))
  expect_success(expect_lint("\t1", list(ranges = list(c(1L, 1L))), whitespace_linter()))
  expect_success(expect_lint("a=1", list(message = lint_msg, line_number = 1L), linter))
  expect_failure(expect_lint("a=1", list(2L, lint_msg), linter))

  expect_error(expect_lint("1:nrow(x)", "(group)", seq_linter()), "Invalid regex result", fixed = TRUE)
})

test_that("multiple checks", {
  expect_success(
    expect_lint(file = "exclusions-test", checks = as.list(rep(lint_msg, 9L)), linters = linter, parse_settings = FALSE)
  )

  expect_success(expect_lint("a=1; b=2", list(lint_msg, lint_msg), linter))
  expect_success(expect_lint("a=1; b=2", list(c(message = lint_msg), c(message = lint_msg)), linter))
  expect_success(expect_lint("a=1; b=2", list(c(line_number = 1L), c(linter = "assignment_linter")), linter))
  expect_success(expect_lint("a=1; b=2", list(lint_msg, c(line = "a=1; b=2", type = "warning")), linter))
  expect_success(expect_lint(c("a=1", "b=2"), list(c(line_number = 1L), c(line_number = 2L)), linter))
  expect_failure(expect_lint(c("a=1", "b=2"), list(c(line_number = 2L), c(line_number = 2L)), linter))

  expect_success(expect_lint("a=1; b=2", list(list(line_number = 1L), list(line_number = 2L)), linter))
  expect_failure(expect_lint("a=1; b=2", list(list(line_number = 2L), list(line_number = 2L)), linter))
  expect_success(
    expect_lint("\t1\n\t2", list("tabs", list(column_number = 1L, ranges = list(c(1L, 1L)))), whitespace_linter())
  )
})

test_that("expect_lint_free works", {
  withr::local_options(
    lintr.rstudio_source_markers = FALSE,
    lintr.linter_file = "lintr_test_config"
  )
  withr::local_envvar(c(NOT_CRAN = "true", R_COVR = "false"))

  expect_lint_free(test_path("dummy_packages", "clean"))
  expect_lint_free(test_path("dummy_packages", "clean_subdir", "r"))
  expect_failure(expect_lint_free(test_path("dummy_packages", "package")))
})

test_that("expect_lint doesn't change language", {
  withr::with_envvar(c(LANGUAGE = "mr"), {
    expect_success(expect_lint("a=1", lint_msg, linter))
    expect_identical(Sys.getenv("LANGUAGE"), "mr")
  })
})