Macro nom_test_helpers::assert_needs

macro_rules! assert_needs {
    ($e:expr, ? ) => { ... };
    ($e:expr, $i:expr) => { ... };
}

This lets the user specify how much input the parser should need

Examples

let r: IResult<&[u8], &[u8]> = IResult::Incomplete(Needed::Unknown);
assert_needs!(r, ?);

let r: IResult<&[u8], &[u8]> = IResult::Incomplete(Needed::Size(2));
assert_needs!(r, 2);