processCss ignores props passed to cssnano via loader query

[mdreizin]

css-loader?{"sourceMap":true,"minimize":true,"safe":true}

lib/processCss.js:157 should use Object.assign instead of Object.create.

var minimizeOptions = Object.create(query);

minimizeOptions will be:

{}

var minimizeOptions = Object.assign({}, query);

minimizeOptions will be:

{ "sourceMap": true, "minimize": true, "safe": true } 

cc @sokra

[jbmusso]

Hi, thanks for spotting this. I'm currently facing the same issue when trying to circumvent the default webpack -p behavior. Indeed, webpack -p seems to be minifying the CSS in a destructive way by default because of cssnano default behavior (to the best of my understanding).
Related: a default behavior of the webpack -p flag could be that webpack unsures a non-destructive minification of css (default to cssnano safe mode, with aggressive/destructive mode being optional/explicit, maybe via a --optimize-aggressive flag). Maybe this could be better raised as a separate issue on the webpack repository.

A safe option was indeed added in css-nano (see cssnano/cssnano#59 merged and available in v3.2.0).

Versions:

• webpack v1.12.2
• css-loader v0.19.0 with cssnano v3.2.0

[salzhrani]

I confirm that @mdreizin pr fixes this issue