Migrating Dark Reader settings from one place to another

script.js

// To use any of the code here, inspect the background view from your browser's extension page
// Chrome:
//   1. chrome://extensions
//   2. "Inspect views background/index.html"
// Firefox:
//   1. about:debugging#/runtime/this-firefox
//   2. Inspect button

// To look at any options you may want to carry over, log all settings
chrome.storage.sync.get(null, console.log);
// Get what you need from the logged object

// Necessary setup {{{
function prepareSyncStorage(values) {
  for (const key in values) {
    const value = values[key];
    const string = JSON.stringify(value);
    const totalLength = string.length + key.length;
    if (totalLength > chrome.storage.sync.QUOTA_BYTES_PER_ITEM) {
      const maxLength =
        chrome.storage.sync.QUOTA_BYTES_PER_ITEM - key.length - 1 - 2;
      const minimalKeysNeeded = Math.ceil(string.length / maxLength);
      for (let i = 0; i < minimalKeysNeeded; i++) {
        values[`${key}_${i.toString(36)}`] = string.substring(
          i * maxLength,
          (i + 1) * maxLength
        );
      }
      values[key] = {
        __meta_split_count: minimalKeysNeeded,
      };
    }
  }
  return values;
}
async function writeSyncStorage(values) {
  return new Promise(async (resolve, reject) => {
    const packaged = prepareSyncStorage(values);
    chrome.storage.sync.set(packaged, () => {
      if (chrome.runtime.lastError) {
        reject(chrome.runtime.lastError);
        return;
      }
      resolve();
    });
  });
}
async function saveSyncSetting(sync) {
  const obj = {syncSettings: sync};
  try {
    await writeSyncStorage(obj);
  } catch (err) {
    console.error(
      "Settings synchronization was disabled due to error:",
      chrome.runtime.lastError
    );
  }
}
// }}}

// Now, you can simply call `writeSyncStorage` with your settings object
writeSyncStorage({ siteList: ["google.com"] })