tests/testthat/test-subset_ncol.R

In wlandau/downsize: A Tool to Downsize Large Analysis Projects for Testing

# library(testthat); library(downsize)
context("subset_ncol")

test_that("Function subset_ncol() runs correctly", {
  set.seed(0)
  data(mtcars)
  a = mtcars
  d = array(sample.int(60), dim = 5:3)

  expect_error(subset_ncol(1:5, 1, F))
  expect_error(subset_ncol(a, 0, F))

  expect_equal(subset_ncol(a, 3, F), a[,1:3])
  expect_equal(subset_ncol(a, NULL, F), a)
  expect_equal(subset_ncol(a, 1e4, F), a)

  b = matrix(rnorm(2*400), ncol = 400)
  x = subset_ncol(b, 1, T)
  expect_equal(dim(x), dim(b[,1, drop = F]))
  expect_false(identical(x, b[,1]))

  expect_equal(subset_ncol(d, 2, F), d[,1:2,])
  expect_equal(subset_ncol(d, Inf, F), d)
  expect_equal(subset_ncol(d, 1, F), d[,1,, drop = F])
})