buster/src/storage/init.js

import {migrate} from 'wesa';

import {isStorageArea} from './storage';

async function initStorage({area = 'local'} = {}) {
  const context = {
    getAvailableRevisions: async ({area} = {}) =>
      (
        await import(/* webpackMode: "eager" */ 'storage/config.json', {
          assert: {type: 'json'}
        })
      ).revisions[area],
    getCurrentRevision: async ({area} = {}) =>
      (await browser.storage[area].get('storageVersion')).storageVersion,
    getRevision: async ({area, revision} = {}) =>
      import(
        /* webpackMode: "eager" */ `storage/revisions/${area}/${revision}.js`
      )
  };

  return migrate(context, {area});
}

async function migrateLegacyStorage() {
  if (await isStorageArea({area: 'sync'})) {
    const {storageVersion: syncVersion} = await browser.storage.sync.get(
      'storageVersion'
    );
    if (syncVersion && syncVersion.length < 14) {
      const {storageVersion: localVersion} = await browser.storage.local.get(
        'storageVersion'
      );

      if (!localVersion || localVersion.length < 14) {
        const syncData = await browser.storage.sync.get(null);
        await browser.storage.local.clear();
        await browser.storage.local.set(syncData);
        await browser.storage.sync.clear();
      }
    }
  }
}

export {initStorage, migrateLegacyStorage};