Cannot find module '@babel/preset-react'-CodePudding

I was trying to deploy my reactjs rails app on heroku.

Everything seems okay until I get this error:

Module build failed (from ./node_modules/babel-loader/lib/index.js):
remote:        Error: Cannot find module '@babel/preset-react'

The app works fine in my localhost. I tried deleting my node_modules folder then running npm install but the error persisted(only when deploying at heroku).

My package.json:

{
  "name": "App",
  "private": true,
  "dependencies": {
    "@rails/webpacker": "5.4.0",
    "@types/react": "^17.0.18",
    "@types/react-dom": "^17.0.9",
    "babel-plugin-transform-react-remove-prop-types": "^0.4.24",
    "prop-types": "^15.7.2",
    "react": "^17.0.2",
    "react-dom": "^17.0.2",
    "react_ujs": "^2.6.1",
    "webpack": "^4.46.0",
    "webpack-cli": "^3.3.12"
  },
  "devDependencies": {
    "@babel/plugin-syntax-jsx": "^7.14.5",
    "@babel/plugin-transform-react-jsx": "^7.14.9",
    "@babel/preset-env": "^7.15.0",
    "@babel/preset-react": "^7.14.5",
    "webpack-dev-server": "^3.11.2"
  }
}

CodePudding user response：

I managed to deploy it. I based my answer here: Why is devDependencies' pruning skipped even if NPM_CONFIG_PRODUCTION is true?

What I did was set:

NPM_CONFIG_PRODUCTION= false 
YARN_PRODUCTION = false
YARN_CONFIG_PRODUCTION = false

I tested changing ENV values and this what worked for me.

This can set at heroku settings under config vars

CodePudding user response：

Heroku defaults to NODE_END=production. How does this affect your build?

You have @babel/preset-react in devDependencies. When you do npm i (or yarn) to install packages with NODE_ENV=production, npm (or yarn) only installs dependencies (it wont install devDependencies).

To get around this, you can -

either override NODE_ENV. ($ NODE_ENV=development npm i)
Run npm i --only=dev before you build

To be on the safe side, revert the value on NODE_ENV to production when you run in production environment (Heroku in your case).