erase-serde-skip

A tiny proc-macro that erases every skip_serializing_if = ... from field-level #[serde(...)] attributes, while leaving all other serde options—and every non-serde attribute—untouched.

WARNING

Do not use in production, has not been extensively tested and is likely very broken.

 Why?

When you serialize → deserialize with Serde, any field marked

#[serde(skip_serializing_if = "...")]

is omitted whenever the predicate is true (eg Option::is_none).

This breaks a lot of binary serialization crates like bincode.

How?

You can add an attribute on top of your struct and it will erase the skip_serializing_if predicates. You likely want to put the attribute behind a feature flag for when you are serializing using something like bincode.

Example 1

use erase_serde_skip::erase_skip_serializing_if;

#[erase_skip_serializing_if]
#[derive(serde::Serialize)]
struct Foo {
    a: u8,
    #[serde(skip_serializing_if = "Option::is_none", rename = "id")]
    b: Option<u32>,
}

After macro expansion this should be:

#[derive(serde::Serialize)]
struct Foo {
    a: u8,
    #[serde(rename = "id")]   // <- skip_serializing_if removed
    b: Option<u32>,
}

Example 2

use erase_serde_skip::erase_skip_serializing_if;
use serde::{Serialize, Deserialize};
use bincode;

#[erase_skip_serializing_if]
#[derive(Serialize, Deserialize, PartialEq, Debug)]
struct Example {
    #[serde(skip_serializing_if = "Option::is_none")]
    maybe: Option<u32>,
}

fn main() {
    let original = Example { maybe: None };

    let bytes = bincode::serialize(&original).unwrap();
    let decoded: Example = bincode::deserialize(&bytes).unwrap();

    assert_eq!(original, decoded);
}

Limitations

• If you've renamed the serde dependency then this crate will leave that field untouched

MSRV

This crate uses syn 2.0, which depends on Rust 1.70+.

 License

Licensed under either of

• Apache License, Version 2.0
• MIT License