title: How to execute my own script after every webpack's auto build in watch mode of vue-cli 3.x?
body: <h2>My current situation</h2>
  
  <p>Now I am using vue-cli@3.9.2. For some reason, I need to watch file change of my source code to run webpack's build, with <code>vue-cli-service build --watch</code>.</p>
  
  <h2>My current solution</h2>
  
  <p>Currently, I run another Node.js process to watch file change, of webpack's bundle. I really suffered from this terrible development experience.</p>
  
  <h2>Compare with vue-cli 2.x</h2>
  
  <p>When I used vue-cli 2.x, I actually run <code>webpack()</code>, one native API of webpack, in <code>build/build.js</code>, so I could use <code>webpack().watch()</code> instead to run build and pass my own script as callback function. However in vue-cli 3.x, there's no way and no need to approach the webpack's native API, within my knowledge.</p>
  
  <h2>Summary</h2>
  
  <p>I wish to run my own script after webpack's every auto build, though I could not find any guidance in vue-cli's official document.</p>