Testing strategy (pragmatic)

What to prioritize

• Public API behavior (exported functions)
• Error behavior (classes + key message content)
• Edge cases (empty input, NA, type mismatches)
• Regression tests for every bug you fix

Patterns

testthat::test_that("...", {
  testthat::expect_equal(...)
  testthat::expect_error(..., class = "rlang_error")
})

Keep tests stable

• Avoid assertions that depend on printing, locale, or session state.
• Prefer small, isolated fixtures over large test data dumps.