tests/testthat/test-resample.R

In CGMossa/rbatteries: Help write R with all the batteries included

test_that("Resample returns a single element on vectors of one length", {
  result <- resample(c(42), replace = TRUE)

  expect_equal(object = result, expected = 42)
})

test_that("Resample can handle up- and down-sampling", {
  x <- 1:5
  up_sampling <- expect_warning(resample(x, n = 10))
  expect_length(up_sampling, n = 10)

  down_sampling <- resample(x, n = 2)
  expect_length(down_sampling, n = 2)
})

test_that("Resample results in NA when upsampling without replacements.", {

  x <- 1:5
  expect_warning(resample(x, n = 10))
  expect_silent(resample(x, n = 10, replace = TRUE))
})


test_that("Resampling on data.frames", {
  iris_no_columns <- ncol(iris)
  iris_no_rows <- nrow(iris)

  new_no_rows <- iris_no_columns - 2
  resampled_iris <- resample(iris, n = new_no_rows)

  resampled_iris_no_columns <- ncol(resampled_iris)
  resampled_iris_no_rows <- nrow(resampled_iris)

  expect_equal(resampled_iris_no_columns, expected = iris_no_columns)
  expect_equal(resampled_iris_no_rows,    expected = new_no_rows)
})


test_that("Resampling one-column data.frame should yield a one column data.frame",{
  sepal_length_10 <- resample(iris[, "Sepal.Length", drop = FALSE], n = 10)
  expect_s3_class(sepal_length_10, "data.frame")

  expect_equal(names(sepal_length_10), expect = c("Sepal.Length"))
  expect_length(sepal_length_10$Sepal.Length, n = 10)

})