CSS is not minified in prod build with master

[trygveaa]

Can you reproduce the problem with latest npm?

Yes

Description

When I'm building to production with the master version of create-react-app, the css is not minified. With the latest released version (v0.9.5) however, it is being minified.

Expected behavior

The css file under build/static/css/ should be minified.

Actual behavior

It is not minified.

Environment

Run these commands in the project folder and fill in their results:

1. npm ls react-scripts (if you haven’t ejected): Running from master, see below.
2. node -v: v7.7.3
3. npm -v: 4.4.4

Then, specify:

1. Operating system: Arch Linux
2. Browser and version: Irrelevant

Reproducible Demo

I can reproduce this by running these commands:

git clone git@github.com:facebookincubator/create-react-app.git .
npm i
npm run create-react-app test-css-minify
cd test-css-minify
npm run build

And looking at the css file that is built under build/static/css/.

[viankakrisna]

seems like minimize option is not turned on in https://github.com/facebookincubator/create-react-app/blob/master/packages/react-scripts/config/webpack.config.prod.js#L198-L200.

[shaunwallace]

looks as though minimize is set to true for the HtmlWebpackPlugin which uses the html-minifier internally but from the docs it seems as this only handles minification of css in style elements and style attributes. See the screenshots attached. In-order to minify the external css the css-loader option would need to be set to true as follows:

{ loader: 'css-loader', options: { importLoaders: 1, minimize: true, }, }

but the above uses cssnano and I am not sure that by setting this boolean to true, which options would be wanted.