sample.js

// Post.js
export default class Post {
    constructor(data) {
        this.id = data.id
        this.title = data.title
        this.body = data.body
    }
}

// PostCtrl.js
import Post from '../models/Post'

export default function PostCtrl($stateParams, PostService) {
    "ngInject";
    
    ctrl = this
    
    PostService.getPost($stateParams.postId)
        .then(function(data) {
            ctrl.post = new Post(data)
        })
        .catch(function(error){
          console.log('error', error)
        })
};