为了使用富文本，决定 DEMO 下 Rails 6。比着几位兄台关于 webpack 在 Rails 6 上的实例，搞了一把。发现有些地方不准确，特别是 bootstrap 部分。应该是这样的：

1、创建 APP

rails new loans -d mysql

2、安装 boostrap jquery 和 popper.js

yarn add bootstrap jquery popper.js

3、在 config/webpack/environment.js 中添加

# config/webpack/environment.js
......
const webpack = require('webpack')
environment.plugins.append( "Provide", new webpack.ProvidePlugin({
    $: 'jquery', 
    jQuery: 'jquery',
    Popper: ['popper.js', 'default'] 
  }))
......

4、在 app/javascript/packs/application.js 中添加

#app/javascript/packs/application.js
......
import "bootstrap"
import "../styles/application"

document.addEventListener("turbolinks:load",() => { 
  $('[data-toggle="tooltip"]').tooltip()
  $('[data-toggle="popover"]').popover() 
})
......

5、在 app/javascript/styles/application.scss 中添加

#app/javascript/styles/application.scss
......
@import 'bootstrap/scss/bootstrap'; 
@import 'fontawesome/scss/fontawesome';
......

以上的初始配置算是完成了，加个 Navbar 试试

6、在 application.html.erb 中加上 bootstrap 的菜单

<nav class="navbar navbar-expand-lg navbar-light bg-light">
  <a class="navbar-brand" href="#">Navbar</a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>

  <div class="collapse navbar-collapse" id="navbarSupportedContent">
    <ul class="navbar-nav mr-auto">
      <li class="nav-item active">
        <a class="nav-link" href="#">Home <span class="sr-only">(current)</span></a>
      </li>
      <li class="nav-item">
        <a class="nav-link" href="#">Link</a>
      </li>
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Dropdown
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdown">
          <a class="dropdown-item" href="#">Action</a>
          <a class="dropdown-item" href="#">Another action</a>
          <div class="dropdown-divider"></div>
          <a class="dropdown-item" href="#">Something else here</a>
        </div>
      </li>
      <li class="nav-item">
        <a class="nav-link disabled" href="#" tabindex="-1" aria-disabled="true">Disabled</a>
      </li>
    </ul>
    <form class="form-inline my-2 my-lg-0">
      <input class="form-control mr-sm-2" type="search" placeholder="Search" aria-label="Search">
      <button class="btn btn-outline-success my-2 my-sm-0" type="submit">Search</button>
    </form>
  </div>
</nav>

以上资料，GG 半天也大搭，百度更白痴，最后在 YT 上找到了一片资料。希望给和我一样刚入门的家伙们节省一点时间。 哦，忘说了，那个 font-awesome 我也没搞定，搜遍全世界也没有只言片语。