10.6 Documentation and code coverage

10.6.1 Vignette

• Long format documentation

• Rmd-first prototyping method

• Either in inst/ or vignettes/

• devtools::build_vignettes()

10.6.2 Code coverage and Continuous Integration

• Code coverage

  • Assess which lines in your code are covered by the tests in tests/
  • usethis::use_coverage() ({covr})
  • Test coverage may be greater, if you have puppeteer / selenium tests
  • covr::package_coverage()

• Test the important stuff, and test it well

• Coverage metrics are easily gamed

• Think about:

  • branch-coverage, not lines-covered
  • will the tests be affected by internal restructuring
  • would restructuring make it easier to test something that currently isn’t covered?

• Continuous Integration

  • eg, for running tests every time you check in code to GitHub
  • Providers: GitHub Actions, GitLab CI, Circle CI, Jenkins, Travis CI
  • usethis::use_github_action
    • prewritten actions for tests, linting, pkgdown …