Here is a problem with parsing .mss files. Because you use sugarss syntax in .mss files so in this case postcss will fire after css modules package, and css modules package will not be able to parse that file.
so you need to use parser option, not plugins. I am afraid that it will not work with nathantreid:css-modules You can try to use PostCSS from that package and not from juliancwirko:postcss but I don’t know if there is an option to configure parser.
@juliancwirko Thank you a lot, glad to see package maintainers here , have tried to use cssModules only, clone css-modules-demo meteor , install npm deps by hands - failed again with package.json
While loading plugin `mss` from package `nathantreid:css-modules`:
<anonymous>: Trailing comma in object at 22:3
},
^
File: "C:\Users\Janis\Documents\Code\css-modules-demo-meteor-1.3\package.json"
at SyntaxError (<anonymous>)
at Object.parseJSON
(C:\Users\Janis\AppData\Local\.meteor\packages\nathantreid_css-modules\1.0.3\plugin.mss.os.windows.x86_32\npm\node_modules\meteor\mss\node_modules\c
json\node_modules\json-parse-helpfulerror\node_modules\jju\lib\parse.js:745:13)
at Object.parse
(C:\Users\Janis\AppData\Local\.meteor\packages\nathantreid_css-modules\1.0.3\plugin.mss.os.windows.x86_32\npm\node_modules\meteor\mss\node_modules\c
json\node_modules\json-parse-helpfulerror\index.js:10:13)
at Object.exports.parse
(C:\Users\Janis\AppData\Local\.meteor\packages\nathantreid_css-modules\1.0.3\plugin.mss.os.windows.x86_32\npm\node_modules\meteor\mss\node_modules\c
json\index.js:90:28)
at Object.load
(C:\Users\Janis\AppData\Local\.meteor\packages\nathantreid_css-modules\1.0.3\plugin.mss.os.windows.x86_32\npm\node_modules\meteor\mss\node_modules\c
json\index.js:223:24)
at loadOptions (packages/mss/options.js:27:19)
at meteorInstall.node_modules.meteor.mss.options.js (packages/mss/options.js:7:1)
at fileEvaluate (packages/modules-runtime.js:158:9)
at require (packages/modules-runtime.js:92:16)
at <runJavaScript-7>:3224:1
at <runJavaScript-7>:3235:3