Prevent preview/dev for unauthenticated workers sites

[EverlastingBugstopper]

We currently prevent wrangler preview if there are namespaces - let's extend that to if there are sites

[bradyjoslin]

What do you think about this change as a way to handle?

Current:

https://github.com/cloudflare/wrangler/blob/9ce660f1d2a75e0e696a378449524a3a516845c2/src/preview/upload.rs#L177

Proposed:

...

fn unauthenticated_upload(target: &Target) -> Result<Preview, failure::Error> {
    let create_address = "https://cloudflareworkers.com/script";
    log::info!("address: {}", create_address);

    // KV namespaces and Sites are not supported by the preview service unless you authenticate
    // so we omit them and provide the user with a little guidance. We don't error out, though,
    // because there are valid workarounds for this for testing purposes.
    let script_upload_form = if target.kv_namespaces.is_some() {
        message::warn(
            "KV Namespaces are not supported in preview without setting API credentials and account_id",
        );
        let mut target = target.clone();
        target.kv_namespaces = None;
        upload::form::build(&target, None)?
    }
    // --- Check for and handle presence of a Site
    else if target.site.is_some() {
        message::warn(
            "Sites are not supported in preview without setting API credentials and account_id",
        );
        let mut target = target.clone();
        target.site = None;
        upload::form::build(&target, None)?
    }
    // ---
    else {
        upload::form::build(&target, None)?
    };
    let client = http::client();
    let res = client
        .post(create_address)
        .multipart(script_upload_form)
        .send()?
        .error_for_status()?;

    let text = &res.text()?;
    log::info!("Response from preview: {:#?}", text);

    let preview: Preview =
        serde_json::from_str(text).expect("could not create a script on cloudflareworkers.com");

    Ok(preview)
}

...

[EverlastingBugstopper]

seems good to me @bradyjoslin 😄

[jspspike]

Hey @bradyjoslin are you planning on making a PR with that change? I can do it if you would like

[bradyjoslin]

Hi @jspspike - please feel free to run with the PR. Thanks for checking!