Single instance aggregate

import {Aggregate} from 'ddbes'

class ApplicationSettings extends Aggregate {
  static function reducer(state = {}, event, commit) {
    switch (event.type) {
      case 'DebugModeEnabled': {
        return {
          ...state,
          debugMode: true,
          updatedAt: commit.committedAt
        }
      }

      case 'DebugModeDisabled': {
        return {
          ...state,
          debugMode: false,
          updatedAt: commit.committedAt
        }
      }

      default: return state
    }
  }

  enableDebug() {
    return this.commit({type: 'DebugModeEnabled'})
  },

  disableDebug() {
    return this.commit({type: 'DebugModeDisabled'})
  }
}

async function testing() {
  const settings = await ApplicationSettings.load()

  await settings.enableDebug()
  settings.state // {debugMode: true, updatedAt: '.....'}

  const timeWhenDebugWasEnabled = new Date()

  // ... time passes and disableDebug() is run elsewhere

  // refresh aggregate instance from snapshots and store
  await settings.hydrate()

  settings.state.debugMode // false

  const settingsAtVersion1 = ApplicationSettings.load({version: 1})
  settings.state.debugMode // true

  const settingsAtSpecificTime = ApplicationSettings.load({time: timeWhenDebugWasEnabled})
  settings.state.debugMode // true
}