Debug eval sources - Firefox Developer Tools 编辑

You can debug JavaScript code that is evaluated dynamically, either as a string passed to eval() or as a string passed to the Function constructor.

In the video below, we load a page containing a source like this:

var script = `function foo() {
               console.log('called foo');
             }
             //# sourceURL=my-foo.js`;

eval(script);

var button = document.getElementById("foo");
button.addEventListener("click", foo, false);

The evaluated string is given the name "my-foo.js" using the //# sourceURL directive. This source is then listed in the source list pane, and can be opened and debugged like any other source.

The name of the source will also appear in stack traces appearing in the Web Console.

The debugger will also stop at debugger; statements in unnamed eval sources.