configuración base para proyecto simple de ReactJs

.babelrc

{
  "presets": ["@babel/preset-env", "@babel/preset-react"]
}

.eslintrc

{
  "env": {
    "browser": true,
    "es6": true,
    "node": true
  },
  "extends": ["airbnb"],
  "globals": {
    "document": false,
    "escape": false,
    "navigator": false,
    "unescape": false,
    "window": false,
    "describe": true,
    "before": true,
    "it": true,
    "expect": true,
    "sinon": true
  },
  "parser": "babel-eslint",
  "plugins": [
    "react",
    "jsx-a11y",
    "import"
  ],
  "rules": {
    "react/jsx-filename-extension": 0,
    "array-bracket-spacing": 2,
    "arrow-body-style": 0,
    "block-scoped-var": 2,
    "brace-style": [2, "1tbs", { "allowSingleLine": true }],
    "comma-spacing": [2, { "before": false, "after": true }],
    "comma-style": [2, "last"],
    "complexity": 0,
    "consistent-return": 1,
    "consistent-this": 0,
    "curly": [2, "multi-line"],
    "default-case": 0,
    "dot-location": [2, "property"],
    "dot-notation": 0,
    "eol-last": 2,
    "eqeqeq": [2, "allow-null"],
    "func-names": 0,
    "func-style": 0,
    "generator-star-spacing": [2, "both"],
    "guard-for-in": 0,
    "handle-callback-err": [2, "^(err|error|anySpecificError)$" ],
    "indent": [2, 2, { "SwitchCase": 1 }],
    "key-spacing": [2, { "beforeColon": false, "afterColon": true }],
    "linebreak-style": 0,
    "max-depth": 0,
    "max-len": [2, 1550, 4],
    "max-nested-callbacks": 0,
    "max-params": 0,
    "max-statements": 0,
    "new-cap": [2, { "newIsCap": true, "capIsNew": false }],
    "newline-after-var": [0, "never"],
    "new-parens": 2,
    "no-alert": 0,
    "no-array-constructor": 2,
    "no-bitwise": 0,
    "no-caller": 2,
    "no-catch-shadow": 0,
    "no-cond-assign": 2,
    "no-console": 0,
    "no-constant-condition": 0,
    "no-continue": 0,
    "no-control-regex": 2,
    "no-debugger": 0,
    "no-delete-var": 2,
    "no-div-regex": 0,
    "no-dupe-args": 2,
    "no-dupe-keys": 2,
    "no-duplicate-case": 2,
    "no-else-return": 2,
    "no-empty": 0,
    "no-empty-character-class": 2,
    "no-labels": 2,
    "no-eq-null": 0,
    "no-eval": 2,
    "no-ex-assign": 2,
    "no-extend-native": 2,
    "no-extra-bind": 2,
    "no-extra-boolean-cast": 2,
    "no-extra-parens": 0,
    "no-extra-semi": 0,
    "no-extra-strict": 0,
    "no-fallthrough": 2,
    "no-floating-decimal": 2,
    "no-func-assign": 2,
    "no-implied-eval": 2,
    "no-inline-comments": 0,
    "no-inner-declarations": [2, "functions"],
    "no-invalid-regexp": 2,
    "no-irregular-whitespace": 2,
    "no-iterator": 2,
    "no-label-var": 2,
    "no-lone-blocks": 0,
    "no-lonely-if": 0,
    "no-loop-func": 0,
    "no-mixed-requires": 0,
    "no-mixed-spaces-and-tabs": [2, false],
    "no-multi-spaces": 2,
    "no-multi-str": 0,
    "no-multiple-empty-lines": [2, { "max": 1 }],
    "no-native-reassign": 2,
    "no-negated-in-lhs": 2,
    "no-nested-ternary": 0,
    "no-new": 2,
    "no-new-func": 2,
    "no-new-object": 2,
    "no-new-require": 2,
    "no-new-wrappers": 2,
    "no-obj-calls": 2,
    "no-octal": 2,
    "no-octal-escape": 2,
    "no-path-concat": 0,
    "no-plusplus": 0,
    "no-process-env": 0,
    "no-process-exit": 0,
    "no-proto": 2,
    "no-redeclare": 2,
    "no-regex-spaces": 2,
    "no-reserved-keys": 0,
    "no-restricted-modules": 0,
    "no-script-url": 0,
    "no-self-compare": 2,
    "no-sequences": 2,
    "no-shadow": 0,
    "no-shadow-restricted-names": 2,
    "no-spaced-func": 2,
    "no-sparse-arrays": 2,
    "no-sync": 0,
    "no-ternary": 0,
    "no-throw-literal": 2,
    "no-trailing-spaces": 2,
    "no-undef": 0,
    "no-undef-init": 2,
    "no-undefined": 0,
    "no-underscore-dangle": 0,
    "no-unneeded-ternary": 2,
    "no-unreachable": 2,
    "no-unused-expressions": 0,
    "no-unused-vars": [2, { "vars": "all", "args": "none" }],
    "no-var": 2,
    "no-void": 0,
    "no-warning-comments": 0,
    "no-with": 2,
    "object-curly-newline": 0,
    "object-curly-spacing": [2, "always"],
    "one-var": 0,
    "operator-assignment": 0,
    "operator-linebreak": [2, "after"],
    "padded-blocks": 0,
    "prefer-const": 2,
    "quote-props": 0,
    "quotes": [2, "single", "avoid-escape"],
    "radix": 2,
    "jsx-quotes": [2, "prefer-single"],
    "jsx-a11y/click-events-have-key-events": 0,
    "jsx-a11y/no-noninteractive-element-interactions": 0,
    "jsx-a11y/media-has-caption": 0,
    "react/display-name": 0,
    "react/jsx-boolean-value": 0,
    "react/jsx-closing-bracket-location": 2,
    "react/jsx-curly-spacing": [2, "never"],
    "react/jsx-equals-spacing": [2, "never"],
    "react/jsx-indent-props": [2, 2],
    "react/jsx-no-bind": [2, { "allowArrowFunctions": true }],
    "react/jsx-no-undef": 2,
    "react/jsx-pascal-case": 2,
    "react/jsx-sort-prop-types": 0,
    "react/jsx-sort-props": 0,
    "react/jsx-uses-react": 2,
    "react/jsx-uses-vars": 2,
    "react/no-did-mount-set-state": 2,
    "react/no-did-update-set-state": 2,
    "react/no-multi-comp": 0,
    "react/no-unknown-property": 2,
    "react/prop-types": 0,
    "react/forbid-prop-types": 0,
    "react/prefer-stateless-function": 0,
    "react/require-default-props": 0,
    "react/react-in-jsx-scope": 2,
    "react/self-closing-comp": 2,
    "react/sort-comp": 0,
    "react/jsx-wrap-multilines": 2,
    "semi-spacing": 0,
    "sort-vars": 0,
    "space-before-blocks": [2, "always"],
    "space-before-function-paren": [2, {"anonymous": "always", "named": "never"}],
    "space-in-parens": [2, "never"],
    "space-infix-ops": 2,
    "keyword-spacing": 2,
    "space-unary-ops": [2, { "words": true, "nonwords": false }],
    "spaced-comment": [0, "always"],
    "strict": 0,
    "use-isnan": 2,
    "valid-jsdoc": 0,
    "valid-typeof": 2,
    "vars-on-top": 2,
    "wrap-iife": [2, "any"],
    "wrap-regex": 0,
    "yoda": [2, "never"]
  }
}

.gitignore

# Node template

# Logs
logs
*.log
npm-debug.log*
yarn-debug.log*
yarn-error.log*

# Runtime data
pids
*.pid
*.seed
*.pid.lock

# Directory for instrumented libs generated by jscoverage/JSCover
lib-cov

# Coverage directory used by tools like istanbul
coverage

# nyc test coverage
.nyc_output

# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
.grunt

# Bower dependency directory (https://bower.io/)
bower_components

# node-waf configuration
.lock-wscript

# Compiled binary addons (https://nodejs.org/api/addons.html)
build/Release

# Dependency directories
node_modules/
jspm_packages/

# Typescript v1 declaration files
typings/

# Optional npm cache directory
.npm

# Optional eslint cache
.eslintcache

# Optional REPL history
.node_repl_history

# Output of 'npm pack'
*.tgz

# Yarn Integrity file
.yarn-integrity

# dotenv environment variables file
.env

# IDE
.idea/*
*.iml
*.sublime-*

# OSX
.DS_Store
.vscode

# Docs Custom
.cache/
yarn-error.log

# Build
dist/

App.jsx

//src/App.jsx

import React from 'react';

const App = () => (
  <h1>Home</h1>
);

export default App;

index.html

//public/index.html  

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Home</title>
  </head>
  <body>
    <div id="app"></div>
  </body>
</html>

index.js

// src/index.js
import React from 'react';
import ReactDOM from 'react-dom';
import App from './App';

ReactDOM.render(<App />, document.getElementById('app'));

install packages

npm install --save react react-dom
npm install --save-dev @babel/core @babel/preset-env @babel/preset-react babel-eslint babel-loader css-loader eslint eslint-plugin-import eslint-plugin-jsx-a11y eslint-plugin-react file-loader html-loader html-webpack-plugin mini-css-extract-plugin node-sass sass-loader eslint-config-airbnb webpack webpack-cli webpack-dev-server

package.json

"scripts": {
    "build": "webpack --mode production",
    "start": "webpack-dev-server --open --mode development"
}

webpack.config.js

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const MiniCssExtractPlugin = require('mini-css-extract-plugin');

module.exports = {
  entry: './src/index.js',
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: 'build.js',
    publicPath: '/',
  },
  resolve: {
    extensions: ['.js', '.jsx'],
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
        },
      },
      {
        test: /\.html$/,
        use: {
          loader: 'html-loader',
        },
      },
      {
        test: /\.(s*)css$/,
        use: [
          {
            loader: MiniCssExtractPlugin.loader,
          },
          'css-loader',
          'sass-loader',
        ],
      },
      {
        test: /\.(png|jpg|gif|svg)$/,
        use: [
          {
            loader: 'file-loader',
            options: {
              name: 'assets/[hash].[ext]',
            },
          },
        ],
      },
    ],
  },
  devServer: {
    historyApiFallback: true,
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: './public/index.html',
      filename: './index.html',
    }),
    new MiniCssExtractPlugin({
      filename: 'assets/[name].css',
    }),
  ],
};