tests/testthat/test-file.R

In privefl/bigdfr: Operate with Data Frames Stored on Disk

context("test-file.R")

test_that("Increasing the file works", {
  expect_true(file.create(tmp <- tempfile()))
  expect_equal(file.size(tmp), 0)
  add_bytes(tmp, 2)
  expect_equal(file.size(tmp), 2)
  add_bytes(tmp, 2)
  expect_equal(file.size(tmp), 4)
  expect_equal(readBin(tmp, 0L), 0)
  add_bytes(tmp, 4)
  expect_equal(file.size(tmp), 8)
  expect_equal(readBin(tmp, 0), 0)
  expect_equal(readBin(tmp, 0L, n = 2), c(0, 0))
  # Don't change content of previous bytes
  writeBin(1:5, tmp <- tempfile())
  expect_equal(file.size(tmp), 20)
  add_bytes(tmp, 8)
  expect_equal(file.size(tmp), 28)
  expect_equal(readBin(tmp, 0L, n = 7), c(1:5, 0, 0))
})