tests/testthat/test-missing_package_linter.R

In lintr: A 'Linter' for R Code

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

  expect_no_lint("library(stats)", linter)
  expect_no_lint('library("stats")', linter)
  expect_no_lint("library('stats')", linter)
  expect_no_lint("library(`stats`)", linter)
  expect_no_lint("library(stats, quietly)", linter)
  expect_no_lint("library(stats, quietly = TRUE)", linter)
  expect_no_lint("require(stats)", linter)
  expect_no_lint("require(stats, quietly = TRUE)", linter)
  expect_no_lint('loadNamespace("stats")', linter)
  expect_no_lint('requireNamespace("stats")', linter)
})

test_that("missing_package_linter blocks disallowed usages", {
  linter <- missing_package_linter()
  lint_msg <- rex::rex("Package 'statts' is not installed.")

  expect_lint("require(statts)", lint_msg, linter)
  expect_lint("library(statts, quietly = TRUE)", lint_msg, linter)
  expect_lint("library(statts, quietly = TRUE)", lint_msg, linter)
  expect_lint('loadNamespace("statts")', lint_msg, linter)
  expect_lint('requireNamespace("statts")', lint_msg, linter)

  expect_lint(
    trim_some("
      library(utils)
      library(statts)
    "),
    list(lint_msg, line_number = 2L, line = "library(statts)"),
    linter
  )
})

test_that("loadNamespace and requireNamespace allow plain symbols", {
  linter <- missing_package_linter()

  expect_no_lint("loadNamespace(mypkg)", linter)
  expect_no_lint("requireNamespace(mypkg)", linter)
})

test_that("character.only=TRUE case is handled", {
  linter <- missing_package_linter()

  expect_no_lint("library(statts, character.only = TRUE)", linter)
  expect_no_lint("require(statts, character.only = TRUE)", linter)
  expect_no_lint('library("stats", character.only = TRUE)', linter)

  expect_lint(
    'library("statts", character.only = TRUE)',
    rex::rex("Package 'statts' is not installed."),
    missing_package_linter()
  )
})