spectacle-code-slide is says "unexpected ! in raw" and won't load properly

Question

I'm trying to include raw Ruby/Elixir/Go/JavaScript code in a spectaclejs presentation.

I'm trying to use CodeSlide as follows:

const example_code = {
  demo: require("raw!./assets/demo.example"),
};

    <CodeSlide
     transition={[]}
     lang="elixir"
     ranges={[]}
     code={example_code.demo}
    />

I get this error in the browser:

./src/presentation.js
  Line 58:  Unexpected '!' in 'raw-loader!./assets/demo.example'. Do not use import syntax to configure webpack loaders  import/no-webpack-loader-syntax

Same issue if I use "raw" instead of "raw-loader", just substitute raw for raw-loader.

I tried what was in this post, but it's not working - am I doing something wrong?

If I remove the "raw*" language from the require statement, I end up with

 /static/media/demo.5b2de2fb.example

in the browser