deku 0.20.3

bit level serialization/deserialization proc-macro for structs
Documentation
#![cfg(feature = "alloc")]

//! General smoke tests for structs

// TODO: These should be divided into smaller tests

#![allow(clippy::unusual_byte_groupings)]

#[cfg(any(feature = "bits", feature = "std"))]
use core::convert::{TryFrom, TryInto};

#[cfg(any(feature = "alloc", feature = "bits", feature = "std"))]
use deku::prelude::*;

mod test_common;

// Common struct to test nesting
#[cfg(feature = "bits")]
#[derive(PartialEq, Debug, DekuRead, DekuWrite, DekuSize)]
pub struct DoubleNestedDeku {
    pub data: u16,
}

#[cfg(feature = "bits")]
// Common struct to test nesting
#[derive(PartialEq, Debug, DekuRead, DekuWrite, DekuSize)]
pub struct NestedDeku {
    #[deku(bits = 6)]
    pub nest_a: u8,
    #[deku(bits = 2)]
    pub nest_b: u8,

    pub inner: DoubleNestedDeku,
}

#[cfg(feature = "bits")]
#[test]
fn test_nested_struct_sizes() {
    assert_eq!(DoubleNestedDeku::SIZE_BYTES, Some(2));
    assert_eq!(NestedDeku::SIZE_BYTES, Some(3));
}

#[cfg(all(feature = "bits", feature = "descriptive-errors"))]
#[test]
#[should_panic(expected = r#"Parse("Too much data: Read 0 but total length was 100")"#)]
fn test_read_too_much_data() {
    #[derive(DekuRead)]
    pub struct TestStruct {
        #[expect(dead_code)]
        #[deku(bits = 6)]
        pub field_a: u8,
    }

    let test_data: &[u8] = &[0u8; 100];
    TestStruct::try_from(test_data).unwrap();
}

#[cfg(feature = "bits")]
#[test]
fn test_unnamed_struct() {
    #[derive(PartialEq, Debug, DekuRead, DekuWrite)]
    pub struct TestUnamedStruct(
        pub u8,
        #[deku(bits = 2)] pub u8,
        #[deku(bits = 6)] pub u8,
        #[deku(bytes = 2)] pub u16,
        #[deku(endian = "big")] pub u16,
        pub NestedDeku,
        #[deku(update = "self.7.len()")] pub u8,
        #[deku(count = "field_6")] pub Vec<u8>,
    );

    let test_data: Vec<u8> = [
        0xff,
        0b1001_0110,
        0xaa,
        0xbb,
        0xcc,
        0xdd,
        0b1001_0110,
        0xcc,
        0xdd,
        0x02,
        0xbe,
        0xef,
    ]
    .to_vec();

    // Read
    let ret_read = TestUnamedStruct::try_from(test_data.as_slice()).unwrap();
    assert_eq!(
        TestUnamedStruct(
            0xff,
            0b0000_0010,
            0b0001_0110,
            native_endian!(0xbbaau16),
            0xccddu16,
            NestedDeku {
                nest_a: 0b00_100101,
                nest_b: 0b10,
                inner: DoubleNestedDeku {
                    data: native_endian!(0xddccu16)
                }
            },
            0x02,
            vec![0xbe, 0xef],
        ),
        ret_read
    );

    // Write
    let ret_write: Vec<u8> = ret_read.try_into().unwrap();
    assert_eq!(test_data, ret_write);
}

#[cfg(feature = "bits")]
#[test]
fn test_named_struct() {
    #[derive(PartialEq, Debug, DekuRead, DekuWrite)]
    pub struct TestStruct {
        pub field_a: u8,
        #[deku(bits = 2)]
        pub field_b: u8,
        #[deku(bits = 6)]
        pub field_c: u8,
        #[deku(bytes = 2)]
        pub field_d: u16,
        #[deku(update = "1+self.field_d")]
        #[deku(endian = "big")]
        pub field_e: u16,
        pub field_f: NestedDeku,
        pub vec_len: u8,
        #[deku(count = "vec_len")]
        pub vec_data: Vec<u8>,
        pub rest: u8,
    }

    let test_data: Vec<u8> = [
        0xff,
        0b1001_0110,
        0xaa,
        0xbb,
        0xcc,
        0xdd,
        0b1001_0110,
        0xcc,
        0xdd,
        0x02,
        0xbe,
        0xef,
        0xff,
    ]
    .to_vec();

    // Read
    let ret_read = TestStruct::try_from(test_data.as_slice()).unwrap();
    assert_eq!(
        TestStruct {
            field_a: 0xff,
            field_b: 0b0000_0010,
            field_c: 0b0001_0110,
            field_d: native_endian!(0xbbaau16),
            field_e: 0xccddu16,
            field_f: NestedDeku {
                nest_a: 0b00_100101,
                nest_b: 0b10,
                inner: DoubleNestedDeku {
                    data: native_endian!(0xddccu16)
                }
            },
            vec_len: 0x02,
            vec_data: vec![0xbe, 0xef],
            rest: 0xff
        },
        ret_read
    );

    // Write
    let ret_write: Vec<u8> = ret_read.try_into().unwrap();
    assert_eq!(test_data, ret_write);
}

#[cfg(all(feature = "alloc", feature = "std"))]
#[test]
fn test_raw_identifiers_struct() {
    #[derive(PartialEq, Debug, DekuRead, DekuWrite)]
    pub struct TestStruct {
        pub r#type: u8,
    }

    let test_data: Vec<u8> = [0xff].to_vec();

    // Read
    let ret_read = TestStruct::try_from(test_data.as_slice()).unwrap();
    assert_eq!(TestStruct { r#type: 0xff }, ret_read);

    // Write
    let ret_write: Vec<u8> = ret_read.try_into().unwrap();
    assert_eq!(test_data, ret_write);
}

#[cfg(feature = "alloc")]
#[test]
fn test_big_endian() {
    #[derive(PartialEq, Debug, DekuRead, DekuWrite)]
    pub struct A {
        #[deku(bytes = "3", endian = "big")]
        address: u32,
    }

    let bytes = [0x11, 0x22, 0x33];
    let a = A::from_bytes((&bytes, 0)).unwrap().1;
    let new_bytes = a.to_bytes().unwrap();
    assert_eq!(bytes, &*new_bytes);

    let bytes = &[0x11, 0x22, 0x33];
    let a = A::from_bytes((bytes, 0)).unwrap().1;
    let new_bytes = a.to_bytes().unwrap();
    assert_eq!(bytes, &*new_bytes);

    #[derive(PartialEq, Debug, DekuRead, DekuWrite)]
    pub struct B {
        #[deku(bytes = "2", endian = "big")]
        address: u32,
    }

    let bytes = [0x00, 0xff, 0xab, 0xaa];
    let a = B::from_bytes((&bytes, 0)).unwrap().1;
    let new_bytes = a.to_bytes().unwrap();
    assert_eq!(&bytes[..2], &*new_bytes);
}

#[cfg(feature = "alloc")]
#[test]
fn test_units() {
    #[derive(DekuRead, DekuWrite)]
    #[deku(magic = b"\xf0")]
    struct Unit;

    let bytes = [0xf0];
    let a = Unit::from_bytes((&bytes, 0)).unwrap().1;
    let new_bytes = a.to_bytes().unwrap();
    assert_eq!(bytes, &*new_bytes);

    let a = Unit;
    let new_bytes = a.to_bytes().unwrap();
    assert_eq!(bytes, &*new_bytes);
}

/// Issue 513
#[cfg(feature = "alloc")]
#[test]
fn test_zst_vec_1() {
    #[derive(Debug, PartialEq, DekuRead)]
    struct EmptyThing {}

    #[derive(Debug, PartialEq, DekuRead)]
    struct ListOfThings {
        #[deku(read_all)]
        things: Vec<EmptyThing>,
    }

    let bytes = vec![];
    let (_y, x) = ListOfThings::from_bytes((&bytes, 0)).unwrap();
    assert_eq!(x.things.len(), 0);
}
/// Issue 513
#[cfg(feature = "alloc")]
#[test]
fn test_zst_vec_2() {
    #[derive(Debug, PartialEq, DekuRead)]
    struct EmptyThing {}

    #[derive(Debug, PartialEq, DekuRead)]
    struct ListOfThings {
        #[deku(bytes_read = "1")]
        things: Vec<EmptyThing>,
    }

    let bytes = vec![];
    let (_y, x) = ListOfThings::from_bytes((&bytes, 0)).unwrap();
    assert_eq!(x.things.len(), 0);
}