Access to serverOptions in eleventy config

[robole]

Is your feature request related to a problem? Please describe.

I created a absoluteurl filter that converts a relative URL or an absolute path to an absolute URL. I would like it to behave like Jekyll's absolute_url filter. It prepends a baseurl value to the input.

The filter should do the following:

• {{ "/about.html" | absoluteurl }} would produce "https://localhost:8080/about.html" in dev. Whatever is the default of the local server.
• {{ "/about.html" | absoluteurl }} would produce "https://www.roboleary.net/about.html" in production when I provide a value of https://www.roboleary.net to baseurl.

Since I cannot obtain the server host name and port, I am unable to do this for dev mode. Instead I return the input url.

Describe the solution you'd like

Access the serverOptions object with details about server.

Describe alternatives you've considered

I tried to use eleventyConfig.getMergingConfigObject().serverOptions in the eleventy config file, however it is empty. I guess that this could be because the server is not initiated yet. Is this a timing issue?

Additional context

This is the current implementation:

function absoluteUrl(url, baseUrl, production = true) {
  if (baseUrl === undefined || baseUrl === null) {
    throw new Error(
      `absoluteUrl - The baseUrl parameter is missing.`
    );
  }

  let absUrl = url;

  if (production) {
    try {
      absUrl = new URL(url, baseUrl).toString();
    } catch (e) {
      debug(
        "Trying to convert %o to be an absolute url with baseUrl %o and failed, returning: %o (invalid url)",
        url,
        baseUrl,
        url
      );
    }
  }

  return absUrl;
}