Testing a package

When we build a package, it is very important to test it. Packages can get very complex structures and this creates a high potential for bugs. The most basic way to test your package is to build and load it again and again and test all its functions simply by using them. But this only works up to a certain package size. If our package gets too big, we cannot test every single function after every change we made to the package.

The better way to test our packages when they reach a certain size is the testthat package, created by Hadley Wickham, who also created the devtools package. This package is available on CRAN, so we can simply install it with the install.packages() function.

Using testthat in a package

Before we can use testthat in your project, we have to call the use_testthat() function from the devtools package once. This function will set up all folders and dependencies and create the tests folder.

This folder includes a testthat.R file and the testthat folder, which...