mobx-store.js

class TodoStore extends BaseStore {
  // Constructor is executed in the  config phase.
  constructor(stores, initialState) {
    super(stores, initialState) // ensures initial state loads for SSR

    // Other store initialization...
  }

  // This is executed in the run phase, after all stores have initialized.
  storeDidInitialize(stores) {
    // Do some work after all stores are ready
  }

  // Observables
  @observable todos = []
  @computed get hasTodos() {
    return this.todos.length > 0
  }

  // Actions (no side-effects outside of store)
  @action loadTodos(todos) {
    this.todos = todos
  }
  
  @action add(todo) {
    this.todos.push(todo)
  }
  
  @action delete(todo) {
    this.todos.delete(todo)
  }
  
  // Effects (potentially calls actions)
  fetchTodos = async() => {
    const todos = await api.getTodos()
    this.loadTodos(todos)
  }
}