Here is the branch and repo in question: https://github.com/Futuratum/moon.holdings/tree/dev

/Users/leongaban/projects/Futuratum/moon.holdings/node_modules/webpack-cli/bin/config-yargs.js:89
describe: optionsSchema.definitions.output.properties.path.description,

Not sure why I'm getting this error, but I upgraded from Webpack 3 to 4.

webpack

/* eslint-disable no-console */

import webpack from 'webpack';

import HtmlWebpackPlugin from 'html-webpack-plugin';

import ExtractTextPlugin from 'extract-text-webpack-plugin';

import CopyWebpackPlugin from 'copy-webpack-plugin';

import path from 'path';



const moonholdings = path.resolve(__dirname, 'moonholdings');

const app = path.resolve(__dirname, 'app');

const nodeModules = path.resolve(__dirname, 'node_modules');



const HtmlWebpackPluginConfig = new HtmlWebpackPlugin({

  template: path.join(__dirname, '/app/index.html'),

  inject: 'body'

});



const ExtractTextPluginConfig = new ExtractTextPlugin({

  filename: 'moonholdings.css',

  disable: false,

  allChunks: true

});



const CopyWebpackPluginConfigOptions = [{

  from: 'app/static',

  to: 'static/'

}];



const CopyWebpackPluginConfig = new CopyWebpackPlugin(CopyWebpackPluginConfigOptions);



const PATHS = {

  app,

  build: moonholdings

};



const LAUNCH_COMMAND = process.env.npm_lifecycle_event;



const isProduction = LAUNCH_COMMAND === 'production';

process.env.BABEL_ENV = LAUNCH_COMMAND;



const productionPlugin = new webpack.DefinePlugin({

  'process.env': {

    NODE_ENV: JSON.stringify('production')

  }

});



const base = {

  entry: ['babel-polyfill', PATHS.app],

  performance: {

    hints: false,

    maxAssetSize: 1000000

  },

  output: {

    path: PATHS.build,

    publicPath: '/',

    filename: 'index_bundle.js'

  },

  resolve: {

    modules: [app, nodeModules]

  },

  module: {

    rules: [

      {

        test: /.js$/,

        loader: 'babel-loader',

        exclude: /node_modules/

      },

      {

        test: /.s?css/,

        use: [

          'style-loader',

          'css-loader',

          'sass-loader'

        ]

      },

      {

        test: /.(png|jpg|jpeg|gif|svg|woff|woff2|ttf|eot)/,

        loader: 'file-loader?name=[path][name].[ext]'

      }

    ]

  }

};



const developmentConfig = {

  devtool: 'inline-source-map',

  devServer: {

    contentBase: moonholdings

  },

  plugins: [

    CopyWebpackPluginConfig,

    ExtractTextPluginConfig,

    HtmlWebpackPluginConfig

  ]

};



const productionConfig = {

  devtool: false,

  plugins: [

    CopyWebpackPluginConfig,

    ExtractTextPluginConfig,

    HtmlWebpackPluginConfig,

    productionPlugin

  ]

};



export default Object.assign(

  {}, base,

  isProduction === true ? productionConfig : developmentConfig

);

package.json

{

  name: moon.holdings,

  version: 1.0.0,

  description: Cryptocurrency asset portfolio,

  main: index.js,

  repository: https://github.com/Futuratum/moon.holdings.git,

  author: Leon Gaban <[email protected]>,

  license: MIT,

  scripts: {

    start: webpack && webpack-dev-server,

    webpack: webpack-dev-server,

    dev: webpack-dev-server,

    build: webpack -p,

    production: webpack -p,

    test: yarn run test-eslint; yarn run test-jest:update,

    test-eslint: eslint app,

    test-eslint:fix: eslint --fix app,

    test-sasslint: ./node_modules/.bin/sass-lint 'app/**/*.scss' -v -q,

    test-jest: jest,

    test-jest:watch: jest --watch,

    test-jest:coverage: jest --coverage,

    test-jest:update: jest --updateSnapshot

  },

  setupFiles: [

    <rootDir>/config/polyfills.js,

    <rootDir>/src/setupTests.js

  ],

  now: {

    name: moonholdings,

    alias: moon.holdings

  },

  jest: {

    moduleNameMapper: {},

    moduleFileExtensions: [

      js,

      jsx

    ],

    moduleDirectories: [

      node_modules,

      app

    ],

    setupTestFrameworkScriptFile: ./app/utils/testConfigure.js

  },

  dependencies: {

    axios: ^0.18.0,

    babel-cli: ^6.26.0,

    babel-core: ^6.26.0,

    babel-eslint: ^8.2.2,

    babel-loader: ^7.1.4,

    babel-plugin-transform-async-to-generator: ^6.24.1,

    babel-plugin-transform-es2015-destructuring: ^6.23.0,

    babel-plugin-transform-es2015-modules-commonjs: ^6.26.0,

    babel-plugin-transform-object-rest-spread: ^6.26.0,

    babel-plugin-transform-runtime: ^6.23.0,

    babel-polyfill: ^6.26.0,

    babel-preset-env: ^1.6.1,

    babel-preset-es2015: ^6.24.1,

    babel-preset-react: ^6.24.1,

    babel-preset-react-hmre: ^1.1.1,

    babel-preset-stage-0: ^6.24.1,

    babel-register: ^6.26.0,

    copy-webpack-plugin: ^4.5.0,

    css-loader: ^0.28.10,

    enzyme: ^3.3.0,

    enzyme-adapter-react-16: ^1.1.1,

    enzyme-to-json: ^3.3.1,

    eslint: ^4.18.2,

    eslint-config-airbnb: ^16.1.0,

    eslint-import-resolver-node: ^0.3.2,

    eslint-plugin-dependencies: ^2.4.0,

    eslint-plugin-import: ^2.9.0,

    eslint-plugin-jsx-a11y: ^6.0.3,

    eslint-plugin-react: ^7.7.0,

    extract-text-webpack-plugin: ^3.0.2,

    file-loader: ^1.1.11,

    flexboxgrid: ^6.3.1,

    git-hooks: ^1.1.10,

    history: ^4.7.2,

    html-webpack-plugin: ^3.0.6,

    jest: ^22.4.2,

    lodash: ^4.17.10,

    node-sass: ^4.7.2,

    path-to-regexp: ^2.2.0,

    ramda: ^0.25.0,

    react: ^16.2.0,

    react-dom: ^16.2.0,

    react-hot-loader: ^4.0.0,

    react-redux: ^5.0.7,

    react-router: ^4.2.0,

    react-router-dom: ^4.2.2,

    react-router-redux: ^4.0.8,

    react-sortable-hoc: ^0.6.8,

    react-test-renderer: ^16.3.2,

    redux: ^3.7.2,

    redux-mock-store: ^1.5.1,

    redux-thunk: ^2.2.0,

    rest: ^2.0.0,

    sass-lint: ^1.12.1,

    sass-loader: ^6.0.7,

    style-loader: ^0.20.2,

    svg-inline-loader: ^0.8.0,

    svg-loader: ^0.0.2,

    url-loader: ^1.0.1,

    webpack: ^4.20.2,

    webpack-cli: ^2.0.10,

    webpack-dev-server: 2.11.1

  }

}