Firebase admin migration example

migrate_example.js

// ===============
// migration function file
// ===============

// disclaimer: i currently have zero focus on performance for migrations, since they are run one time ever
module.exports = async (adminFb) => {
  try {
    const directoriesSnap = await adminFb
      .database()
      .ref('directories')
      .once('value');

    const directories = directoriesSnap.val();

    const ids = Object.keys(directories);

    await ids.reduce(async (promise, id) => {
      await promise;

      await adminFb
        .database()
        .ref('directories')
        .child(id)
        .child('config')
        .update({
          email: false,
          sms: false
        });
    }, Promise.resolve());

    return true;
  } catch (err) {
    console.log('error updating config for directories', err);
    throw err;
  }
};

// ===============
// migration exports example
// ===============

// v0
const migrationA = require('./migration_function_file');

// v1
const migrationB = require('./migration_function_file_b');

module.exports.versions = {
  0: [migration],
  1: [migration1],
};

module.exports.latestVersion = 1;

// when running migration scripts, i check my database property at `meta/migration_version`,
// and run any versions higher than that, up to and including `latestVersion` number, which can differ
// by environment depending on when i'm rolling out features in each