tests/testthat/test_tripping.R

In snappier: Compress and Decompress 'Snappy' Encoded Data

library(hedgehog)

# A generator which can generate very large lists quickly
# at the expense of individual element shrinking.
biglist <- function(elements, from = 0, to = 10000 ) {
  gen.shrink(shrink.list,
    gen.impure(function(g_size) {
      paste(sample(elements , size = sample(from:to, 1), replace = T), collapse = "")
    })
  )
}

test_that("compression and decompression are bijective", {
  forall(
      biglist(c(LETTERS, letters, 0:9))
    , function(x) { expect_equal (decompress(compress(x)), x) }
  )

  forall(
      gen.map(as.raw, gen.c(gen.element(0:255), to = 50))
    , function(x) { expect_equal (decompress_raw( compress_raw (x)), x) }
  )

  # The empty string is an interesting case in that it will contain
  # NULL chars. These would break an attempt to place the compressed data
  # in a character vector.
  expect_equal("", decompress(compress("")))

  # Just another test.
  expect_equal("snappy compressed", decompress(compress("snappy compressed")))
})