ohmigrate

Minimal framework for migrating databases or whatever from one version to the next.

Getting started

var omg = require('ohmigrate')
 
omg({
  should: function (name, cb) {
    // Should I run migration called `name`?
    // Callback `cb` with true/false to begin
    cb(null, true)
  },
 
  did: function (name, cb) {
    // Migration called `name` ran successfully
    // Next migration doesn't start until you call `cb`
    cb()
  },
 
  done: function (err) {
    // All migrations ran successfully, or an error occurred
    if (err) throw err
  },
 
  ctx: {db: require('./db')} // Context (this) in migration functions
})

Your migrations go in process.cwd() + '/migrations' and must be prefixed with a semver version number followed by a "_". Migrations are run sequentially in semver version order.

e.g.

.
└── migrations
    ├── 0.0.0_create-admin.js
    ├── 0.0.1_add-fields.js
    ├── 1.0.0_replace-missing.js
    ├── 1.1.0_dodge-viper.js
    ├── 2.0.0_new-schema.js
    ├── 2.0.1_more-schema.js
    └── 2.0.2_too-much-schema.js

Migrations look like this:

module.exports = function (cb) {
  // Do some stuff with this.db, then...in some future...
  cb()
}

Options

should

Function that determines if a migration needs to be run. It is passed the name of the migration (the filename without '.js') and a callback that should be called with true/false depending on whether the migration should be run.

did

Function called after a migration completes successfully. It is passed the name of the migration and a callback that should be called to begin the next migration.

done

Function called once when all migrations complete successfully, or when an error occurs during a migration. If an error occurs, it is passed the error object.

ctx

Object referred to by this in your migration functions.

dir

String path to the directory where migrations can be found. It defaults to process.cwd() + '/migrations'.