To cite package ‘unitizer’ in publications use:

  Gaslam B (2024). _unitizer: Interactive R Unit Tests_. R package
  version 1.4.21, <https://github.com/brodieg/unitizer>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {unitizer: Interactive R Unit Tests},
    author = {Brodie Gaslam},
    year = {2024},
    note = {R package version 1.4.21},
    url = {https://github.com/brodieg/unitizer},
  }