Add an Attachment type to axum-extra

[joeydewaal]

Refs #2768

Motivation

When trying to send an attachment from Axum it includes,

• Setting a Content-Disposition header.
• Using the provided Html, Css, JavaScript or Wasm types or setting a Content-Type header.

I think this could be made a bit easier.

Solution

Add an Attachment response type to axum-extra. This type adds a Content-Disposition header and optionally a Content-Type header to the response.

example:

async fn cargo_toml() -> Result<Attachment<String>, (StatusCode, String)> {
    let file_contents = tokio::fs::read_to_string("Cargo.toml").await
        .map_err(|err| (StatusCode::NOT_FOUND, format!("File not found: {err}")))?;

    Ok(Attachment::new(file_contents)
        .filename("Cargo.toml")
        .content_type("text/x-toml"))
}

[jplatte]

Thanks for the PR! A few small suggestions below.

[jplatte]

CI failure seems unrelated, if you have an idea on how to fix it, a separate PR would be appreciated. Otherwise I'll try to find some time to fix it soon.

[joeydewaal]

Thanks for your review and changes, I changed the code. I don't know why CI is failing if I have some time I'll try and fix it.

[jplatte]

I looked and the rustdoc failure is really just 2 spaces of indentation missing. Since I can't approve / merge my own PRs, do you mind just adding that to this? It's such a trivial change that I don't mind it being rolled up into another PR.

[joeydewaal]

Ofcourse!

[jplatte]

Okay, looks like there's more to it. Sorry, I'll go fix it myself in the next couple of days (and I hope David will be around to merge not too long after).

[joeydewaal]

Almost there, it's complaining about MakeErasedRouter is never constructed. Is it okay is I add an #[allow(dead_code)] to that type?

[jplatte]

Sure, I suspect that there's more that should be done eventually, but to unblock CI that seems like the best solution.

[jplatte]

Thank you!