Testing on the R track

Learn how to test your R exercises on Exercism

Tests for this track make use of the testthat package.

To install the package, simply open up R and run:


You can check that the package is installed successfully by running:


Each problem will have a script named test_<exercise-name>.R (e.g. test_hello-world.R).

To run the tests for an exercise, simply execute this R script.

In RStudio, this is as simple as opening the test script, and clicking "Source" at the top right of the source pane. This will load your solution code through the source command on the first line of the test script, and then execute the suite of testthat tests that follow.

Note however, that the source() command on the first line of the test script will only work if your solution script (<exercise-name>.R) is located in your working directory. If this is not the case, you'll need to either:

  • change your working directory eg. setwd('exercism/r/hello-world/'), or
  • update the first line of the test script e.g. source('exercism/r/hello-world/hello-world.R')

If you prefer, you can also run the tests from the command line with Rscript path_to_exercise_directory/test_<exercise-name>.R (e.g. Rscript hello-world/test_hello-world.R)

Another convenient way to run these tests is to make use of testthat's auto_test function. Since exercism code and tests are located in the same folder, use this same path for both the code_path and test_path parameters. After running auto_test(), the tests for the exercise will be executed automatically each time you update/save your R code for the exercise. This can help facilitate rapid iteration while working on your solution.