out = {"concat-#{random.int()}.mp4"}

s1 = single("first-concat.mp4")
s2 = single("second-concat.mp4")
s3 = single("third-concat.mp4")
s = sequence([s1, s2, s3, switch([])])

done = ref(false)

#clock.assign_new(sync='none', [s])
def on_close(filename) =
  if
    not done()
  then
    done := true

    process.run("sync")

    ojson =
      process.read(
        "ffprobe -v quiet -print_format json -show_streams #{process.quote(filename)}"
      )

    let json.parse {streams = [{duration}]} = ojson

    # Actual time is 59.93..
    if
      int(float_of_string(duration)) == 59
    then
      test.pass()
    else
      test.fail()
    end
  end
end

output.file(fallible=true, on_close=on_close, %ffmpeg(%video.copy), out, s)
