@nathamanath/state-machine

A TypeScript finite state machine library.

• Home: https://nathamanath.gitlab.io/state-machine/
• Documentation: https://nathamanath.gitlab.io/state-machine/
• Repo: https://gitlab.com/nathamanath/state-machine
• Issues: https://gitlab.com/nathamanath/state-machine/-/issues
• NPM: https://www.npmjs.com/package/@nathamanath/state-machine

Installation

yarn add @nathamanath/state-machine

npm install @nathamanath/state-machine

Usage

State machine has many states, each state has transitions and actions. Transitions declare which states you can change to from current state, actions initiate transitions.

Here we have an on/off switch example. Its too basic to actually be practical on its own, but does show usage.

See /examples, and /tests for more.

import {
  StateMachine,
  State,
  Action,
  Transition
} from '@nathamanath/state-machine'

const stateMachine = new StateMachine({
  initialState: 'off',

  states: [
    new State({
      name: 'off',

      actions: [
        new Action({
          name: 'toggle',
          callback: (m) => {
            m.transition('on')
          }
        })
      ],

      transitions: [new Transition({ to: 'on' })],

      enter: () => {},

      leave: () => {}
    }),

    new State({
      name: 'on',

      actions: [
        new Action({
          name: 'toggle',
          callback: (m) => {
            m.transition('off')
          }
        })
      ],

      transitions: [new Transition({ to: 'off' })],

      enter: () => {},

      leave: () => {}
    })
  ]
}).init()

console.log(stateMachine.state!.name) // 'off'

stateMachine.commit('toggle')

console.log(stateMachine.state!.name) // 'on'

Author

Nathan Goddard - Initial work

License

This project is licensed under the MIT License - see the LICENSE file for details.