pixie/tests/fuzz_png.nim

import random, strformat, pixie/fileformats/png, pixie/common, pngsuite

randomize()

for i in 0 ..< 10_000:
  let file = pngSuiteFiles[rand(pngSuiteFiles.len - 1)]
  var data = cast[seq[uint8]](
    readFile(&"tests/images/png/pngsuite/{file}.png")
  )
  let
    pos = 29 + rand(data.len - 30)
    value = rand(255).uint8
  data[pos] = value
  echo &"{i} {file} {pos} {value}"
  try:
    let img = decodePng(data)
    doAssert img.height > 0 and img.width > 0
  except PixieError:
    discard

  data = data[0 ..< pos]
  try:
    let img = decodePng(data)
    doAssert img.height > 0 and img.width > 0
  except PixieError:
    discard