http POST: missing boundary with content-type "multipart/form-data"

Currently it is not possible to use "multipart/form-data" as content-type posting form-data with the http module due to missing boundary.

Example using the JS-API setting content-type by hand resulting in missing boundary:

return await http.fetch(url, {
    method: "POST",
    headers: {
        "Content-Type": "multipart/form-data",
    },
    responseType: 1,
    body: http.Body.form({
        name: "test"
    })
});

This might be an issue with attohttpc, leaving the content type blank the content-type defaults to "application/x-www-form-urlencoded".

I am using the latest version of tauri (1.0.0-beta.4).

[nothingismagick]

This is a great finding, thankyou! I see a couple options here:

1. You create a custom command and use something like reqwest
2. We create an advanced plugin using something like reqwest
3. We replace our current client with something like reqwest

[lucasfernog]

The issue is that we need to use the dedicated multipart APIs to support this:
https://docs.rs/reqwest/0.11.4/reqwest/struct.RequestBuilder.html#method.multipart
https://docs.rs/attohttpc/0.17.0/attohttpc/struct.MultipartBuilder.html

But the crate's design for multipart is filled with references, so it's tricky to implement it without introducing a breaking change.

[mgedgaudas]

This is a great finding, thankyou! I see a couple options here:

1. You create a custom command and use something like reqwest
2. We create an advanced plugin using something like reqwest
3. We replace our current client with something like reqwest

Would be nice if someone could provide an example how a custom command would look like for sending multipart form with files if this feature is not going to natively supported any time soon.

[FabianLars]

@mgedgaudas
Kinda ugly cause i'm lazy, but that should provide the basics:

#[tauri::command]
async fn upload_file(file: std::path::PathBuf) -> Result<(), String> {
                  // ^We expect the frontend to send a file path.

    let client = reqwest::Client::new();

    let file_name = file.file_name().unwrap().to_string_lossy().to_string();
    let file_content = tokio::fs::read(file).await.map_err(|err| err.to_string())?;
    let part = reqwest::multipart::Part::bytes(file_content).file_name(file_name);
    let form = reqwest::multipart::Form::new().part("file", part);

    client
        .post("URL_HERE")
        .multipart(form)
        .send()
        .await
        .map_err(|err| err.to_string())?;

    Ok(())
}

You need to enable the multipart feature for reqwest.
And while you're at it you probably want to add the reqwest-client feature flag to tauri in Cargo.toml so that you don't bundle 2 different http libs into the binary (the default one is attohttpc)