Bundling and Minification
Debugging Bundled and Minified JavaScript
It's easy to debug your JavaScript in a development environment (where the compilation Element in the Web.config file is set to debug="true" ) because the JavaScript files are not bundled or minified. You can also debug a release build where your JavaScript files are bundled and minified. Using the IE F12 developer tools, you debug a JavaScript function included in a minified bundle using the following approach:
debug
Optional Boolean attribute.
Specifies whether to compile debug binaries rather than retail binaries.
The default is False.