test_modifier_with2.rs

use jbytes_derive::{ByteEncode, ByteDecode};
use jbytes::prelude::*;


/// This is just a demonstration, so go straight back.
fn custom_with_decode<I: BufRead>(input: &I, _cattr: Option<&ContainerAttrModifiers>, _fattr: Option<&FieldAttrModifiers>) -> JResult<WithExample> {
    let key = match input.take_bytes(3)? {
        b"get" => 1,
        b"put" => 2,
        _ => return Err(make_error(input.get_position(), ErrorKind::Fail)),
    };

    let value = input.take_u32()?;

    Ok(WithExample {key, value})
}


fn custom_with_encode<B: BufWrite>(buffer: &mut B, _cattr: Option<&ContainerAttrModifiers>, _fattr: Option<&FieldAttrModifiers>, value: &WithExample) -> JResult<usize> {
    let mut r_nbytes = match value.key {
        1 => buffer.push_bytes(b"get")?,
        2 => buffer.push_bytes(b"put")?,
        _ => 0,
    };

    r_nbytes += buffer.push_u32(value.value)?;

    Ok(r_nbytes)
}


#[derive(Debug, PartialEq, Eq, ByteEncode, ByteDecode)]
#[jbytes(decode_with="custom_with_decode", encode_with="custom_with_encode")]
pub struct WithExample {
    pub key: u8,
    pub value: u32,
}


#[test]
fn test_modifier_with() {
    let bytes = Bytes::new(b"get\x00\x00\x00\x01");
    assert_eq!(WithExample::decode(&bytes).unwrap(), WithExample { key: 1, value: 1 });
    assert_eq!(bytes.remaining_len(), 0);

    assert_eq!(*jbytes::encode(WithExample { key: 1, value: 1 }).unwrap(), b"get\x00\x00\x00\x01");
}