R Testing

When to Activate

• Writing tests with testthat in R packages
• Mocking HTTP calls or functions in tests
• Setting up coverage reporting with covr
• Testing Shiny applications with shinytest2
• Choosing between expect_equal and expect_identical for numeric vs. exact comparison
• Using snapshot testing to lock in the printed output of S3 objects or complex data structures
• Enforcing a minimum coverage percentage in CI with covr::percent_coverage
• Running property-based tests with hedgehog to verify algebraic laws like commutativity or idempotence

testthat 3e — Modern Syntax