title: simple js source mapping
body: <p>I'm developing a tool that dynamically load javascript in the browser.</p>
  
  <p>I want to allow users to debug generated code, but I also want to hide some of the generated line while debugging.</p>
  
  <p>Example of the generated source:</p>
  
  <pre><code>define('simple','simple',function(module) {
     module.exports = function gogogo() {
        var a = require("./a");
        var b = require("./b");
        return a + b;
    };
  });
  </code></pre>
  
  <p>Ideally, I want the first and last line to be hidden while debugging in devtools.
  I know I could use source mapping, but I want to know if there is a simple way to just hide some line in debugger, or if there is some tool to generate a source map for this simple use case.</p>