Google Apps Script Hoisting and ReferenceError

I've been trying to find an answer to this for a few weeks, but couldn't quite do this, so I decided to ask.

I sometimes get this error:

ReferenceError: <SomeObject> is not defined

...whereas I know for sure that it is. The problem is that the object is located in a different file, so if I call the object from that file (or maybe even a third file), the code does work.

I believe this must have to do with how hoisting works, meaning I'm trying to call an object before it's declared.

But then how does it work exactly when you have different files?

Here's an example:

If I have the following code in one file and I run getID(), it works:

const SomeAPI = (function () {
  const _auth = new WeakMap();
  const _url = new WeakMap();

  class SomeAPI {
    constructor(url, user = DEFAULT_USER, pwd = DEFAULT_PWD) {
      _url.set(this, url);
      _auth.set(this, Utilities.base64Encode(`${user}:${pwd}`));
    }

    async fetch() {
      const headers = {
        Authorization: `Basic ${_auth.get(this)}`,
      };

      const options = {
        headers,
      };

      const response = await UrlFetchApp.fetch(_url.get(this), options);
      const data = JSON.parse(response);
      return data;
    }
  }

  return SomeAPI;
})();

const LIST_DATA = (async () => await getListData())();

async function getListData() {
  const response = await new SomeAPI(ALL_SETTINGS['List API URL']).fetch();
  return Array.isArray(response) ? response[0] : response;
}


const getID = async () => {
  const listData = await LIST_DATA;
  const listId = listData.list_id;
  const id = {
    sheetId: SpreadsheetApp.getActive().getId(),
    listId
  };
  console.log(id);
  return id;
};

However, if I move LIST_DATA, getListData() and getID() to a different file, I get:

ReferenceError: SomeAPI is not defined

Overall the project is composed of 17 different files.

All help is greatly appreciated!