Unit Testing with R

my_code.R

# Example for simple function to be tested
#
# 1. Change working directory
# 2. Call: testthat::test_dir('tests') within RStudio or R

increment <- function(value) {
  value + 1
}

test_my_code.R

source("../my_code.R", chdir = TRUE)
library(testthat)

test_that("single number", {
  expect_equal(increment(-1), 0)
  expect_equal(increment(0), 1)
})

test_that("vectors", {
  expect_equal(increment(c(0,1)), c(1,2))
})

test_that("empty vector", {
  expect_equal(increment(c()), c())
})

test_that("test NA", {
  expect_true(is.na(increment(NA)))
})