import rand fn test_rand_bytes() ? { mut randoms := []string{} for i in 0 .. 100 { x := rand.bytes(i) ?.hex() if x.len > 0 { randoms << x } assert x.len == i * 2 } mut differences := 0 for idx in 1 .. randoms.len { start := randoms[idx]#[0..8] prev_start := randoms[idx - 1]#[0..8] if start != prev_start { differences++ } } assert differences > 95 // normally around 98 dump(differences) } fn test_rand_read() ? { max := 50 mut a := []byte{len: max} mut differences := 0 for j in 1 .. max { start := '00'.repeat(j) for k in j + 1 .. max { end := '00'.repeat(max - k) middle := '00'.repeat(k - j) // eprintln('> j: $j | k: $k | start: $start | middle: $middle | end: $end') for i in 0 .. max { a[i] = 0 } assert a[j..k].hex() == middle for i in 0 .. 10 { rand.read(mut a[j..k]) // dump(a.hex()) assert a[0..j].hex() == start assert a[k..].hex() == end if a[j..k].hex() != middle { differences++ } } } } dump(differences) assert differences > 11700 // normally around 11758 }