ts-async-state-machine v2.0.0

Simple Async State Machine

Description

the objective is to provide a simple interface to build a finite state machine

Features

• thoroughly tested with good code coverage
• small package file: 3.2kb (compressed)
• written in TypeScript and therefore includes a definitions file with full documentation (*.d.ts)

Core Concepts

• Define a set of States, each with a name, a list of fromStates and some optional callbacks
• Call .transition('newStateName') to trigger a state change to the specified state

• Use Promises inside the onBeforeEnter callback to resolve/reject the state change (usually via server API)

  Example Usage

  import { Machine } from "ts-async-state-machine";

// Create your Machine const MicrowaveMachine = new Machine('Microwave');

// Add States to the Machine MicrowaveMachine.addState('off', 'running', { onBeforeEnter: (prevState) => new Promise((resolve, rejection) => { // use a server APi request to 'confirm' the state change resolve();// resolves the state transition - changes 'MicrowaveMachine's state to 'off' // a 'rejection' will fail the internal state transition }) }); MicrowaveMachine.addState('on', 'off', { // callbacks are optional and use them as needed: 'onEnter', 'onExit', 'onBeforeEnter' as options onExit: () => { console.log('Exited ON state') } }); MicrowaveMachine.addState('running', 'on', { onEnter: () => { console.log('Entered RUNNING State') } });

// Initialise into your required starting state MicrowaveMachine.start('off');

// Start Triggering State changes when neccessary MicrowaveMachine.transition('on').then(newState => { console.log('Entered State', newState.name) }); // omitted 'catch' for brevity

MicrowaveMachine.transition('running').then(newState => { console.log('Entered State', newState.name) });

## Examples
* see `/examples` folder for a full examples in `microwave.js`, `traffic-light.js` and `traffic-light-server-stateful.js`
* run microwave example: `npm run example`
* other examples: `npm run build && node ./examples/traffic-light.js`
* other examples: `npm run build && node ./examples/traffic-light-server-stateful.js`

## Development
* build: `npm run build`
* test: `npm run test`
* code coverage: `npm run test:coverage`

## Credits
* Inspired by the Js Async State machine lib [https://github.com/robguy21/js-async-state-machine](https://github.com/robguy21/js-async-state-machine)