tests/testthat/test-build_tools.R

In pkgbuild: Find Tools Needed to Build R Packages

test_that("tests always run in environment with dev tools", {
  without_cache({
    expect_true(has_build_tools())
    expect_equal(has_rtools(), is_windows())
  })
})

test_that("unless specifically disabled", {
  without_compiler({
    expect_false(has_build_tools())
    expect_false(has_rtools())
  })
})