how to test a R script

sample.R

Combine <- function(df1, df2, fmt) {
  # 同じサイズの2つの行列を用いて、各セル値を合成します。
  #
  # Args:
  #   df1: 行列1
  #   df2: 行列2
  #   fmt: 表示書式(sprintf)
  #
  # Returns:
  #   合成した行列
  matrix(sprintf(df1, df2, fmt = fmt), nrow = nrow(df1), dimnames = dimnames(df1))
}

test_sample.R

# usage:
#   library(testthat)
#   source('<path of sample.R>')
#   test_file('<path of this file'>)
test_that('Combine works', {
          m1 <- cbind(c('hoge', 'huga', 'hige'),
                      c(1, 2, 3))
          m2 <- cbind(c('a', 'b', 'c'),
                      c(5, 6, 7))
          combined <- Combine(m1, m2, "%s %s")
          expect_equal(combined[1,1], 'hoge a')
          expect_equal(combined[3,2], '3 7')
})