"css should not be empty" error

[mihajlija]

Hi, I'm having the same problem as #31 and I'd really appreciate some help. I have a much simpler config so I figured I'd open a separate issue.

I'm using Bootstrap with a little bit of custom CSS and I'm injecting content in the DOM with JavaScript. This plugin runs last in my webpack config.

1. The code: Glitch app
2. Steps to reproduce:

• Run webpack in Glitch console

3. Expected behavior: Critical detects the CSS from index.html
4. What happens: I get "css should not be empty" error even though it's seemingly in the right place (/public/main.css) and not empty
5. Temporary fix: Explicitly specifying the CSS file in the plugin config

• Uncomment line "css should not be empty" error #37 in webpack.config.js
• Run webpack and then refresh to update the editor with files generated from the console

@thescientist13 mentioned that the issue might be due to empty HTML at the time of evaluation, but it's not quite empty, there is an h1 element there.