Exodus NPM | npm.io

exodus

Framework-agnostic migrations

Install

$ npm i -g exodus

Node 10+ is recommended.

Usage

Exodus allows you to create migration definitions, modules that allow you to introduce version-controlled changes in your application, such as adding a field to a database or changing a configuration for your e-commerce.

Exodus was largely inspired by the flexibility and user experience of migrat, and much of the configurable behavior and templates have been forked from there.

CLI

$ exodus --help

  Usage
    $ exodus <action>

  Possible actions
    init              Adds a config file in your project directory
    create <name>     Creates a new file in your migrations dir
    migrate           Runs all remaining migrations

  Options
    --help

  For more information, see:
  https://github.com/Sleavely/exodus-migrations

Migrations

A migration definition is a regular Node module that exposes an up() method that introduces a change, and a down() method that allows the user (that's you!) to reverse the change later.

An example migration might look like:

const { load, save } = require('../utils/db-methods')
//Apply the change
exports.up = async () => {
  const users = await load('users')
  for (let user of users) {
    user.age = user.age + 1
  }
  await save('users', users)
}

// Revert the change
exports.down = async () => {
  const users = await load('users')
  for (let user of users) {
    user.age = user.age - 1
  }
  await save('users', users)
}

Configuration

The init command will create a configuration file in your current directory.

All properties are optional.

module.exports = exports = {
  /**
   * @name migrationsDirectory
   *
   * The folder to store migration scripts in,
   * relative to your configuration file.
   */
  // migrationsDirectory: './migrations',

  /**
   * @name context
   *
   * Invoked at the beginning of a run, this method can return
   * an object with any details you want passed through to all
   * migrations, such as database connections, loggers, etc.
   *
   * @return {object}
   */
  // context: async () => { return {} },

  /**
   * @name storeState
   *
   * Called to persist current migration state. Use this to store
   * the `state` argument in Redis, to disk, your database etc.
   * If undefined, Exodus falls back to exodus.state.json
   *
   * @param state The state object to be stored.
   * @param context The object you returned in `context`
   */
  // storeState: async (state, context) => {},

  /**
   * @name fetchState
   *
   * This method is responsible for fetching the current
   * migration state, persisted by `storeState`.
   * If undefined, Exodus falls back to exodus.state.json
   *
   * @param context The object you returned in `context`
   * @return {object}
   */
  // fetchState: async (context) => {},

  /**
   * @name beforeAll
   *
   * Executed right before any of the queued migrations are run.
   *
   * @param {migrationJob[]}
   */
  // beforeAll: async (pendingMigrations) => {},

  /**
   * @name beforeEach
   *
   * Executed before each migration.
   *
   * @param {migrationJob}
   */
  // beforeEach: async (migrationJob) => {},

  /**
   * @name afterEach
   *
   * Executed after each migration.
   *
   * @param {migrationJob}
   */
  // afterEach: async (migrationJob) => {},

  /**
   * @name afterAll
   *
   * Executed after the final pending migration was run.
   *
   * @param {migrationJob[]}
   */
  // afterAll: async (pendingMigrations) => {},

}