When I try to use Parcel to build a production version of a React app that works fine in development mode, I get "Cannot find module 'sass'" - node.js

Question

I've built a simple React/Redux app and am using Parcel for the bundler. It works fine in development mode, that is, using the script
"dev": "parcel ./src/index.html",
but when I tried to do
"build": "parcel build ./src/index.html",
I got the following error
/Users/abc/Documents/Projects/sandbox/smart/src/styles/main.scss: Cannot find module 'sass' from '/Users/abc/Documents/Projects/sandbox/smart/src/styles'
at /Users/abc/Documents/Projects/sandbox/smart/node_modules/resolve/lib/async.js:97:35
at processDirs (/Users/abc/Documents/Projects/sandbox/smart/node_modules/resolve/lib/async.js:244:39)
at isdir (/Users/abc/Documents/Projects/sandbox/smart/node_modules/resolve/lib/async.js:251:32)
at /Users/abc/Documents/Projects/sandbox/smart/node_modules/resolve/lib/async.js:23:69
at FSReqWrap.oncomplete (fs.js:152:21)
This is the first time I've tried to build an app using Parcel and I'm lost. I'm using node-sass to import my sass files directly -- perhaps this has something to do with that.
The referenced file (main.scss) is referenced in App.js like this
import "../../styles/main.scss";
and is the first sass file to be included (App is loaded into the DOM like this in index.js:
const store = configureStore()
ReactDOM.render(
<Provider store={store}>
<App />
</Provider>,
document.getElementById("root")
)
This is running under Node 11.15. My package.json follows -- any hints or help much appreciated!
{
"name": "friender",
"version": "1.0.0",
"description": "",
"main": "index.js",
"jest": {
"setupFiles": ["jest-localstorage-mock"]
},
"scripts": {
"dev": "parcel ./src/index.html",
"build": "parcel build ./src/index.html",
"lint": "eslint \"src/**/*.{js,jsx}\" --quiet",
"test": "jest"
},
"prettier": {
"semi": false
},
"keywords": [],
"author": "",
"license": "MIT",
"devDependencies": {
"#babel/cli": "^7.6.0",
"#babel/core": "^7.6.0",
"#babel/plugin-transform-runtime": "^7.5.5",
"#babel/preset-env": "^7.6.0",
"#types/jest": "^24.0.18",
"babel-eslint": "^10.0.3",
"babel-preset-react": "^7.0.0-beta.3",
"eslint": "^6.2.2",
"eslint-config-prettier": "^6.1.0",
"jest": "^24.9.0",
"jest-localstorage-mock": "^2.4.0",
"parcel-bundler": "^1.12.3",
"prettier": "^1.18.2"
},
"dependencies": {
"#emotion/babel-preset-css-prop": "^10.0.14",
"#emotion/core": "^10.0.16",
"#emotion/styled": "^10.0.15",
"#fortawesome/fontawesome-svg-core": "^1.2.0-7",
"#fortawesome/free-solid-svg-icons": "^5.11.1",
"#fortawesome/react-fontawesome": "^0.1.4",
"axios": "^0.19.0",
"bulma": "^0.7.5",
"eslint-plugin-jest": "^22.17.0",
"eslint-plugin-react": "^7.14.3",
"immer": "^4.0.0",
"node-sass": "^4.12.0",
"prop-types": "^15.7.2",
"react": "16.x",
"react-detect-offline": "^2.4.0",
"react-dom": "^16.9.0",
"react-fontawesome": "^1.6.1",
"react-modal": "^3.10.1",
"react-redux": "^7.1.1",
"redux": "^4.0.4",
"redux-devtools-extension": "^2.13.8",
"redux-thunk": "^2.3.0"
}
}

Answer 1

Try instead per the documentation for SCSS and error Cannot find module 'sass' use module sass instead of node-sass:
npm install -D sass
The documentation mentions being able to use node-sass, but there are several active issues with node-sass. Module sass may help resolve the error and allow you use SCSS in your application.
Hopefully that helps!