package.json

{
  "private": true,
  "name": "classy-test",
  "scripts": {
    "install": "cd node_modules && git clone https://github.com/charto/classy-mst.git && cd classy-mst && git checkout develop && tsc -d --outdir dist src/index.ts src/classy-mst.ts",
    "test": "tsc && mocha"
  },
  "license": "MIT",
  "devDependencies": {
    "@types/mocha": "^2.2.47",
    "mocha": "^2.5.3",
    "typescript": "^2.6.2"
  },
  "dependencies": {
    "@types/node": "^9.4.0",
    "mobx": "^3.4.1",
    "mobx-state-tree": "^1.3.1"
  }
}

test.ts

import {types, flow} from 'mobx-state-tree'
import {mst, shim, action} from 'classy-mst'

const TodoData = types
  .model({
    title: types.string,
    done: false
  })
  .named('TodoData')

class TodoCode extends shim(TodoData) {
  get isDone(): boolean {
    return this.done
  }
  @action
  toggle() {
    this.done = !this.done
  }

  @action
  run() {
    return flow(function*() {
      yield Promise.resolve('This gets lost')
      return 'Returned value'
    })()
  }
}

const Todo = mst(TodoCode, TodoData)
const NewTodoData = Todo.props({count: 0})
class NewTodoCode extends shim(NewTodoData, Todo) {
  @action
  toggle() {
    console.log('Toggled ' + ++this.count + ' times!')
    super.toggle()
  }
}
const NewTodo = mst(NewTodoCode, NewTodoData)
describe('hello', () => {
  it('first', async done => {
    try {
      const t = Todo.create({title: '123'})
      t.toggle()
      console.log(await t.run())
      console.log(t.isDone)
      done()
    } catch (e) {
      done(e)
    }
  })
})

tsconfig.json

{
	"compileOnSave": true,
	"compilerOptions": {
		"declaration": true,
		"experimentalDecorators": true,
		"lib": [ "es5", "es2015.collection", "es2015.promise" ],
		"module": "commonjs",
		"moduleResolution": "node",
		"noImplicitAny": true,
		"noImplicitThis": true,
		"removeComments": false,
		"strictNullChecks": true,
		"target": "es5"
	},
	"files": [
		"test.ts"
	]
}