Lower capped RAND generators

[CowBoy4mH3LL]

Basically, there is a min_size aside from the max_size in the RAND generators (RandBytesGenerator and RandPrintablesGenerator).
This allows to generate rand bytes sequences from min_size to max_size, e.g. between 2 bytes and 4 bytes or 1 byte and 1 byte for that matter.
Becomes extremely useful if we are aware of the recipient's acceptance bounds.
If not, simply keep min_size as 1 and the older behavior is restored.

[tokatoka]

good.
but can you not to change the original constructor? which sets the min_size to the default value of 1
and make another constructor for you, that takes two args (min and max)

[domenukk]

Yes let's add a with_min_size constructor instead of changing the existing API

[CowBoy4mH3LL]

Sounds good!! Ill make that change.
I that case though, do we need new test cases showing this new constructor?

[domenukk]

You can change one of them, for example baby_fuzzer_custom_input or any other of your choice :)

[domenukk]

Nice thx! :)
Clippy is still a bit unhappy:

error: this method could have a `#[must_use]` attribute
   --> libafl/src/generators/mod.rs:108:5
    |
108 |     pub fn with_min_size(min_size: NonZeroUsize, max_size: NonZeroUsize) -> Self {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add the attribute: `#[must_use] pub fn with_min_size(min_size: NonZeroUsize, max_size: NonZeroUsize) -> Self`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#must_use_candidate
    = note: `-D clippy::must-use-candidate` implied by `-D clippy::pedantic`
    = help: to override `-D clippy::pedantic` add `#[allow(clippy::must_use_candidate)]`

error: this method could have a `#[must_use]` attribute
   --> libafl/src/generators/mod.rs:148:5
    |
148 |     pub fn with_min_size(min_size: NonZeroUsize, max_size: NonZeroUsize) -> Self {
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: add the attribute: `#[must_use] pub fn with_min_size(min_size: NonZeroUsize, max_size: NonZeroUsize) -> Self`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#must_use_candidate

[CowBoy4mH3LL]

1. Semantically are two must_use attributes allowed for the same struct?
2. Can you help me with this one error - can't seem to relate to any code I introduced -- https://github.com/AFLplusplus/LibAFL/actions/runs/11757949843/job/32755797517?pr=2671

[domenukk]

The second error isn't related to your changes, sorry :)
For must_use it's not struct related at all, but for a method.
So just change

 pub fn with_min_size(min_size: NonZeroUsize, max_size: NonZeroUsize) -> Self {

to

#[must_use]
 pub fn with_min_size(min_size: NonZeroUsize, max_size: NonZeroUsize) -> Self {

That should be all :)

[CowBoy4mH3LL]

Done on this one!!
Thanks guys!!
BTW, the Papa Roach stegos in the code must stay :)

[domenukk]

Thank you!