Add default to option

[lmk123]

When I use this plugin to generate source map, it removed the source map path in the css file.

Before:

#id{color:red}
/*# sourceMappingURL=my.css.map */

After I use this plugin:

#id{color:red}

My config looks like this:

var OptimizeCSSPlugin = require('optimize-css-assets-webpack-plugin')

module.exports = {
  devTool: 'source-map',
  plugins: [
    new OptimizeCSSPlugin({
      cssProcessorOptions: {
        map: { inline: false } // generate sourcemap use an external file
      }
    })
  ]
}

The PostCSS document says:

To ensure that you generate an accurate source map, you must indicate the input and output CSS file paths — using the options from and to, respectively.

So I add a default to option to keep source map path in the css file.

[NMFR]

This is a bit intrusive, because it makes assumptions about the CSS processor's options.
But on the other side we really don't have a choice because the assetName is on our side.

In the weekend i will test it and make a new version on npm.

Thanks for the help.

[NMFR]

Tested and published on npm

[lmk123]

Thanks!