#[allow(clippy::option_option)] not working when paired with #[serde(deserialize_with)]

[schungx]

Using: VS Code with RLS, Windows

This produces clippy warning on option_option:

    #[allow(clippy::option_option)]
    #[serde(deserialize_with = "func")]
    #[serde(skip_serializing_if = "Option::is_none")]
    #[serde(default)]
    #[serde(borrow)]
    foo: Option<Option<Cow<'a, str>>>,

consider using `Option<T>` instead of `Option<Option<T>>` or a custom enum if you need to distinguish all 3 cases.

However, removing #[serde(deserialize_with ... )] makes it work:

    #[allow(clippy::option_option)]
    #[serde(skip_serializing_if = "Option::is_none")]
    #[serde(default)]
    #[serde(borrow)]
    foo: Option<Option<Cow<'a, str>>>,

I suspect #[serde(serialize_with ...)] will also trip up this feature. So something about serde's serialize_with and deserialize_with attributes conflict with option_option.

[flip1995]

Minimal reproducer:

use serde::{Deserialize, Deserializer, Serialize}; // 1.0.94
use std::borrow::Cow;

#[derive(Serialize, Deserialize)]
struct Foo<'a> {
    #[allow(clippy::option_option)]
    #[serde(deserialize_with = "func")]
    #[serde(skip_serializing_if = "Option::is_none")]
    #[serde(default)]
    #[serde(borrow)]
    foo: Option<Option<Cow<'a, str>>>,
}

#[allow(clippy::option_option)]
fn func<'a, D>(_: D) -> Result<Option<Option<Cow<'a, str>>>, D::Error>
where
    D: Deserializer<'a>,
{
    Ok(Some(Some(Cow::Borrowed("hi"))))
}

fn main() {}

Playground

The warning messages are because of the expansion of deserialize_with. This probably just needs a macro check.

[tnielens]

Seems to be fixed, @flip1995 reproduction example does not trigger any lint.

[schungx]

Seems to be fixed

Yes, it looks like it fixed itself a while ago.

Closing this one.

[tnielens]

The uitest suite on this test case still triggers incorrectly. Maybe a serde version difference? This issue could stay open.

[ThibsG]

@montrivo, do you remember if the error was triggering only in CI or also locally?
I don't get the error locally by removing #[allow(clippy::option_option)].

[tnielens]

I don't remember anymore.