To cite package ‘doctest’ in publications use:

  Hugh-Jones D (2024). _doctest: Generate Tests from Examples Using
  'roxygen' and 'testthat'_. R package version 0.3.0,
  <https://github.com/hughjonesd/doctest>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {doctest: Generate Tests from Examples Using 'roxygen' and 'testthat'},
    author = {David Hugh-Jones},
    year = {2024},
    note = {R package version 0.3.0},
    url = {https://github.com/hughjonesd/doctest},
  }