Software Testing for Data Science in R
Packages for unit testing and assertive testing that are actively maintained:
Packages for unit testing


testthat: more information on how to use you can find here or on github
Runit: Cran page


Packages for assertions:


assertthat: info on github
assertive: Assertive has a lot of subpackages available in case you do not need all of them. check on cran
assertr: info on github
ensurer: info on github
tester: info on github


It is a matter of preference what you want to use for assertions. 
Read this bioconductor page for more info on the difference between RUnit and testthat.