r/tests/testthat/test-buffer.R

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context("Buffer")

test_that("Buffer can be created from raw vector", {
  vec <- raw(123)
  buf <- buffer(vec)
  expect_r6_class(buf, "Buffer")
  expect_equal(buf$size, 123)
})

test_that("Buffer can be created from integer vector", {
  vec <- integer(17)
  buf <- buffer(vec)
  expect_r6_class(buf, "Buffer")
  expect_equal(buf$size, 17 * 4)
})

test_that("Buffer can be created from numeric vector", {
  vec <- numeric(17)
  buf <- buffer(vec)
  expect_r6_class(buf, "Buffer")
  expect_equal(buf$size, 17 * 8)
})

test_that("Buffer can be created from complex vector", {
  vec <- complex(3)
  buf <- buffer(vec)
  expect_r6_class(buf, "Buffer")
  expect_equal(buf$size, 3 * 16)
})

test_that("buffer buffer buffers buffers", {
  expect_r6_class(buffer(buffer(42)), "Buffer")
})

test_that("Other types can't be converted to Buffers", {
  expect_error(
    buffer(data.frame(a="asdf")),
    "Cannot convert object of class data.frame to arrow::Buffer"
  )
})

test_that("can convert Buffer to raw", {
  buf <- buffer(rnorm(10))
  expect_equal(buf$data(), as.raw(buf))
})

test_that("can read remaining bytes of a RandomAccessFile", {
  tbl <- tibble::tibble(
    int = 1:10, dbl = as.numeric(1:10),
    lgl = sample(c(TRUE, FALSE, NA), 10, replace = TRUE),
    chr = letters[1:10]
  )
  tab <- Table$create(!!!tbl)

  tf <- tempfile()
  all_bytes <- write_feather(tab, tf)

  file <- ReadableFile$create(tf)
  expect_equal(file$tell(), 0)
  x <- file$Read(20)$data()
  expect_equal(file$tell(), 20)
  y <- file$Read()$data()

  file <- ReadableFile$create(tf)
  z <- file$Read()$data()

  file <- ReadableFile$create(tf)
  a <- file$ReadAt(20)$data()

  expect_equal(file$GetSize(), length(x) + length(y))
  expect_equal(z, c(x, y))
  expect_equal(a, y)
})

test_that("Buffer$Equals", {
  vec <- integer(17)
  buf1 <- buffer(vec)
  buf2 <- buffer(vec)
  expect_equal(buf1, buf2)
  expect_true(buf1$Equals(buf2))
  expect_false(buf1$Equals(vec))
})