使用 monorepo (Lerna + Yarn Workspaces) 共享代码的 ReactJS linting (eslint) 和 transpiling (babel) 错误

Question

I´m building a monorepo using yarn workspaces, lerna and 2 different projects:

• ux - a React component library built using create-react-app
• auth - a React application that uses ux library built using create-react-app and then ejected (the ejection was done to try to solve the current linting and transpiling error).

My monorepo setup is:

project
  |-------- node_modules
  |-------- lerna.json
  |-------- package.json
  |-------- packages
                |----------- auth
                             |------- node_modules
                             |------- src
                             |------- packages.json
                |----------- ux
                             |------- node_modules
                             |------- src
                             |------- packages.json

lerna.json:

{
  "lerna": "2.9.0",
  "npmClient": "yarn",
  "useWorkspaces": true,
  "packages": [
    "packages/*"
  ],
  "version": "3.0.0"
}

Lerna root package.json:

{
    "name": "myorganization",
    "version": "3.0.0",
    "license": "UNLICENSED",
    "workspaces": ["packages/*"],
    "private": true,
    "scripts": {
        "clean": "lerna clean -f --yes && rm -rf node_modules",
        "reset": "yarn run clean && yarn",
        "auth": "cd packages/auth && yarn start"
    },
    "devDependencies": {
        "lerna": "^2.9.0"
    }
}

ux package.json: (ux was not ejected)

{
  "name": "@myorganization/ux",
  "version": "3.0.0",
  "author": "Me",
  "private": true,
  "license": "UNLICENSED",
  "dependencies": {
    "react": "^16.2.0",
    "react-dom": "^16.2.0",
    "react-scripts": "2.0.0-next.9754a231"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject"
  },
  "browserslist": {
    "development": [
      "last 2 chrome versions",
      "last 2 firefox versions",
      "last 2 edge versions"
    ],
    "production": [
      ">1%",
      "last 4 versions",
      "Firefox ESR",
      "not ie < 11"
    ]
  },
  "devDependencies": {
    "eslint": "^4.19.0",
    "eslint-plugin-react": "^7.7.0"
  }
}

auth package.json:

{
  "name": "@myorganization/auth",
  "version": "3.0.0",
  "private": true,
  "author": "Me",
  "license": "UNLICENSED",
  "dependencies": {
    "@myorganization/ux": "^3.0.0",
    "@babel/core": "7.0.0-beta.38",
    "@babel/runtime": "7.0.0-beta.38",
    "autoprefixer": "7.2.5",
    "babel-core": "7.0.0-bridge.0",
    "babel-eslint": "8.2.1",
    "babel-jest": "22.1.0",
    "babel-loader": "8.0.0-beta.0",
    "babel-preset-react-app": "4.0.0-next.9754a231",
    "case-sensitive-paths-webpack-plugin": "2.1.1",
    "chalk": "2.3.0",
    "css-loader": "0.28.9",
    "dotenv": "4.0.0",
    "dotenv-expand": "4.0.1",
    "eslint-config-react-app": "3.0.0-next.9754a231",
    "eslint-loader": "1.9.0",
    "eslint-plugin-flowtype": "2.41.0",
    "eslint-plugin-import": "2.8.0",
    "eslint-plugin-jsx-a11y": "6.0.3",
    "extract-text-webpack-plugin": "3.0.2",
    "file-loader": "1.1.6",
    "fs-extra": "5.0.0",
    "html-webpack-plugin": "2.30.1",
    "identity-obj-proxy": "3.0.0",
    "jest": "22.1.2",
    "object-assign": "4.1.1",
    "postcss-flexbugs-fixes": "3.2.0",
    "postcss-loader": "2.0.10",
    "promise": "8.0.1",
    "raf": "3.4.0",
    "react": "^16.2.0",
    "react-dev-utils": "6.0.0-next.9754a231",
    "react-dom": "^16.2.0",
    "react-router-dom": "^4.2.2",
    "style-loader": "0.19.1",
    "svgr": "1.6.0",
    "sw-precache-webpack-plugin": "0.11.4",
    "thread-loader": "1.1.2",
    "uglifyjs-webpack-plugin": "1.1.6",
    "url-loader": "0.6.2",
    "webpack": "3.10.0",
    "webpack-dev-server": "2.11.0",
    "webpack-manifest-plugin": "1.3.2",
    "whatwg-fetch": "2.0.3"
  },
  "scripts": {
    "start": "node scripts/start.js",
    "build": "node scripts/build.js",
    "test": "node scripts/test.js --env=jsdom"
  },
  "browserslist": {
    "development": [
      "last 2 chrome versions",
      "last 2 firefox versions",
      "last 2 edge versions"
    ],
    "production": [
      ">1%",
      "last 4 versions",
      "Firefox ESR",
      "not ie < 11"
    ]
  },
  "jest": {
    "collectCoverageFrom": [
      "src/**/*.{js,jsx,mjs}"
    ],
    "setupFiles": [
      "<rootDir>/config/polyfills.js"
    ],
    "testMatch": [
      "<rootDir>/src/**/__tests__/**/*.{js,jsx,mjs}",
      "<rootDir>/src/**/?(*.)(spec|test).{js,jsx,mjs}"
    ],
    "testEnvironment": "node",
    "testURL": "http://localhost",
    "transform": {
      "^.+\\.(js|jsx|mjs)$": "<rootDir>/node_modules/babel-jest",
      "^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
      "^(?!.*\\.(js|jsx|mjs|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
    },
    "transformIgnorePatterns": [
      "'[/\\\\]node_modules[/\\\\](?!' + paths.allLernaModules.join('|') + ').*\\.(js|jsx|mjs)$'",
      "^.+\\.module\\.css$"
    ],
    "moduleNameMapper": {
      "^react-native$": "react-native-web",
      "^.+\\.module\\.css$": "identity-obj-proxy"
    },
    "moduleFileExtensions": [
      "web.js",
      "mjs",
      "js",
      "json",
      "web.jsx",
      "jsx",
      "node"
    ]
  },
  "babel": {
    "presets": [
      "react-app"
    ]
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "devDependencies": {
    "eslint": "^4.19.0",
    "eslint-plugin-react": "^7.7.0"
  }
}

Then I´ve changed the create-react-app created config/paths to grab the referenced packages:

"use strict";

const path = require("path");
const fs = require("fs");
const url = require("url");

// Make sure any symlinks in the project folder are resolved:
// https://github.com/facebookincubator/create-react-app/issues/637
const appDirectory = fs.realpathSync(process.cwd());
const resolveApp = relativePath => path.resolve(appDirectory, relativePath);

const envPublicUrl = process.env.PUBLIC_URL;

function ensureSlash(path, needsSlash) {
  const hasSlash = path.endsWith("/");
  if (hasSlash && !needsSlash) {
    return path.substr(path, path.length - 1);
  } else if (!hasSlash && needsSlash) {
    return `${path}/`;
  } else {
    return path;
  }
}

const getPublicUrl = appPackageJson =>
  envPublicUrl || require(appPackageJson).homepage;

// We use `PUBLIC_URL` environment variable or "homepage" field to infer
// "public path" at which the app is served.
// Webpack needs to know it to put the right <script> hrefs into HTML even in
// single-page apps that may serve index.html for nested URLs like /todos/42.
// We can't use a relative path in HTML because we don't want to load something
// like /todos/42/static/js/bundle.7289d.js. We have to know the root.
function getServedPath(appPackageJson) {
  const publicUrl = getPublicUrl(appPackageJson);
  const servedUrl =
    envPublicUrl || (publicUrl ? url.parse(publicUrl).pathname : "/");
  return ensureSlash(servedUrl, true);
}

// config after eject: we're in ./config/
module.exports = {
  dotenv: resolveApp(".env"),
  appPath: resolveApp("."),
  appBuild: resolveApp("build"),
  appPublic: resolveApp("public"),
  appHtml: resolveApp("public/index.html"),
  appIndexJs: resolveApp("src/index.js"),
  appPackageJson: resolveApp("package.json"),
  appSrc: resolveApp("src"),
  yarnLockFile: resolveApp("yarn.lock"),
  testsSetup: resolveApp("src/setupTests.js"),
  appNodeModules: resolveApp("node_modules"),
  publicUrl: getPublicUrl(resolveApp("package.json")),
  servedPath: getServedPath(resolveApp("package.json"))
};

module.exports.lernaRoot = path
  .resolve(resolveApp("."), "../")
  .endsWith("packages")
  ? path.resolve(resolveApp("."), "../../")
  : resolveApp(".");

module.exports.appLernaModules = [];

module.exports.appLernaNodeModules = path.join(
  module.exports.lernaRoot,
  "node_modules"
);

fs.readdirSync(module.exports.appLernaNodeModules).forEach(folderName => {
  if (folderName === "react-scripts") return;
  if (folderName.substr(0, 1) === ".") return;

  let fullName = path.join(module.exports.appLernaNodeModules, folderName);

  if (folderName.substr(0, 1) === "@" && fs.lstatSync(fullName).isDirectory()) {
    fs.readdirSync(fullName).forEach(subFolderName => {
      let subFullName = path.join(fullName, subFolderName);

      if (fs.lstatSync(subFullName).isSymbolicLink()) {
        let src = fs.realpathSync(subFullName);
        module.exports.appLernaModules.push(src);
      }
    });
  }

  if (fs.lstatSync(fullName).isSymbolicLink()) {
    module.exports.appLernaModules.push(fs.realpathSync(fullName));
  }
});

And changed the create-react-app original webpack.config.dev to:

"use strict";

const autoprefixer = require("autoprefixer");
const path = require("path");
const webpack = require("webpack");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const CaseSensitivePathsPlugin = require("case-sensitive-paths-webpack-plugin");
const InterpolateHtmlPlugin = require("react-dev-utils/InterpolateHtmlPlugin");
const WatchMissingNodeModulesPlugin = require("react-dev-utils/WatchMissingNodeModulesPlugin");
const eslintFormatter = require("react-dev-utils/eslintFormatter");
const ModuleScopePlugin = require("react-dev-utils/ModuleScopePlugin");
const getClientEnvironment = require("./env");
const paths = require("./paths");

// Webpack uses `publicPath` to determine where the app is being served from.
// In development, we always serve from the root. This makes config easier.
const publicPath = "/";
// `publicUrl` is just like `publicPath`, but we will provide it to our app
// as %PUBLIC_URL% in `index.html` and `process.env.PUBLIC_URL` in JavaScript.
// Omit trailing slash as %PUBLIC_PATH%/xyz looks better than %PUBLIC_PATH%xyz.
const publicUrl = "";
// Get environment variables to inject into our app.
const env = getClientEnvironment(publicUrl);

// Options for PostCSS as we reference these options twice
// Adds vendor prefixing based on your specified browser support in
// package.json
const postCSSLoaderOptions = {
  // Necessary for external CSS imports to work
  // https://github.com/facebookincubator/create-react-app/issues/2677
  ident: "postcss",
  plugins: () => [
    require("postcss-flexbugs-fixes"),
    autoprefixer({
      flexbox: "no-2009"
    })
  ]
};

console.log(paths.appLernaModules.concat(paths.appSrc));


// This is the development configuration.
// It is focused on developer experience and fast rebuilds.
// The production configuration is different and lives in a separate file.
module.exports = {
  // You may want 'eval' instead if you prefer to see the compiled output in DevTools.
  // See the discussion in https://github.com/facebookincubator/create-react-app/issues/343.
  devtool: "cheap-module-source-map",
  // These are the "entry points" to our application.
  // This means they will be the "root" imports that are included in JS bundle.
  // The first two entry points enable "hot" CSS and auto-refreshes for JS.
  entry: [
    // We ship a few polyfills by default:
    require.resolve("./polyfills"),
    // Include an alternative client for WebpackDevServer. A client's job is to
    // connect to WebpackDevServer by a socket and get notified about changes.
    // When you save a file, the client will either apply hot updates (in case
    // of CSS changes), or refresh the page (in case of JS changes). When you
    // make a syntax error, this client will display a syntax error overlay.
    // Note: instead of the default WebpackDevServer client, we use a custom one
    // to bring better experience for Create React App users. You can replace
    // the line below with these two lines if you prefer the stock client:
    // require.resolve('webpack-dev-server/client') + '?/',
    // require.resolve('webpack/hot/dev-server'),
    require.resolve("react-dev-utils/webpackHotDevClient"),
    // Finally, this is your app's code:
    paths.appIndexJs
    // We include the app code last so that if there is a runtime error during
    // initialization, it doesn't blow up the WebpackDevServer client, and
    // changing JS code would still trigger a refresh.
  ],
  output: {
    // Add /* filename */ comments to generated require()s in the output.
    pathinfo: true,
    // This does not produce a real file. It's just the virtual path that is
    // served by WebpackDevServer in development. This is the JS bundle
    // containing code from all our entry points, and the Webpack runtime.
    filename: "static/js/bundle.js",
    // There are also additional JS chunk files if you use code splitting.
    chunkFilename: "static/js/[name].chunk.js",
    // This is the URL that app is served from. We use "/" in development.
    publicPath: publicPath,
    // Point sourcemap entries to original disk location (format as URL on Windows)
    devtoolModuleFilenameTemplate: info =>
      path.resolve(info.absoluteResourcePath).replace(/\\/g, "/")
  },
  resolve: {
    // This allows you to set a fallback for where Webpack should look for modules.
    // We placed these paths second because we want `node_modules` to "win"
    // if there are any conflicts. This matches Node resolution mechanism.
    // https://github.com/facebookincubator/create-react-app/issues/253
    modules: ["node_modules", paths.appNodeModules].concat(
      // It is guaranteed to exist because we tweak it in `env.js`
      process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
    ),
    // These are the reasonable defaults supported by the Node ecosystem.
    // We also include JSX as a common component filename extension to support
    // some tools, although we do not recommend using it, see:
    // https://github.com/facebookincubator/create-react-app/issues/290
    // `web` extension prefixes have been added for better support
    // for React Native Web.
    extensions: [".web.js", ".mjs", ".js", ".json", ".web.jsx", ".jsx"],
    alias: {
      // Support React Native Web
      // https://www.smashingmagazine.com/2016/08/a-glimpse-into-the-future-with-react-native-for-web/
      "react-native": "react-native-web"
    },
    plugins: [
      // Prevents users from importing files from outside of src/ (or node_modules/).
      // This often causes confusion because we only process files within src/ with babel.
      // To fix this, we prevent you from importing files out of src/ -- if you'd like to,
      // please link the files into your node_modules/ and let module-resolution kick in.
      // Make sure your source files are compiled, as they will not be processed in any way.
      new ModuleScopePlugin(paths.appSrc, [paths.appPackageJson])
    ]
  },
  module: {
    strictExportPresence: true,
    rules: [
      // Disable require.ensure as it's not a standard language feature.
      { parser: { requireEnsure: false } },

      // First, run the linter.
      // It's important to do this before Babel processes the JS.

      {
        test: /\.(js|jsx|mjs)$/,
        enforce: "pre",
        use: [
          {
            options: {
              formatter: eslintFormatter,
              eslintPath: require.resolve("eslint")
            },
            loader: require.resolve("eslint-loader")
          }
        ],
        include: paths.appLernaModules.concat(paths.appSrc)
      },
      {
        // "oneOf" will traverse all following loaders until one will
        // match the requirements. When no loader matches it will fall
        // back to the "file" loader at the end of the loader list.
        oneOf: [
          // "url" loader works like "file" loader except that it embeds assets
          // smaller than specified limit in bytes as data URLs to avoid requests.
          // A missing `test` is equivalent to a match.
          {
            test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
            loader: require.resolve("url-loader"),
            options: {
              limit: 10000,
              name: "static/media/[name].[hash:8].[ext]"
            }
          },
          // Process application JS with Babel.
          // The preset includes JSX, Flow, and some ESnext features.
          {
            test: /\.(js|jsx|mjs)$/,
            include: paths.appLernaModules.concat(paths.appSrc),
            use: [
              // This loader parallelizes code compilation, it is optional but
              // improves compile time on larger projects
              require.resolve("thread-loader"),
              {
                loader: require.resolve("babel-loader"),
                options: {
                  // This is a feature of `babel-loader` for webpack (not Babel itself).
                  // It enables caching results in ./node_modules/.cache/babel-loader/
                  // directory for faster rebuilds.
                  cacheDirectory: true,
                  highlightCode: true
                }
              }
            ]
          },
          // Process any JS outside of the app with Babel.
          // Unlike the application JS, we only compile the standard ES features.
          {
            test: /\.js$/,
            use: [
              // This loader parallelizes code compilation, it is optional but
              // improves compile time on larger projects
              require.resolve("thread-loader"),
              {
                loader: require.resolve("babel-loader"),
                options: {
                  babelrc: false,
                  compact: false,
                  presets: [
                    require.resolve("babel-preset-react-app/dependencies")
                  ],
                  cacheDirectory: true,
                  highlightCode: true
                }
              }
            ]
          },
          // "postcss" loader applies autoprefixer to our CSS.
          // "css" loader resolves paths in CSS and adds assets as dependencies.
          // "style" loader turns CSS into JS modules that inject <style> tags.
          // In production, we use a plugin to extract that CSS to a file, but
          // in development "style" loader enables hot editing of CSS.
          // By default we support CSS Modules with the extension .module.css
          {
            test: /\.css$/,
            exclude: /\.module\.css$/,
            use: [
              require.resolve("style-loader"),
              {
                loader: require.resolve("css-loader"),
                options: {
                  importLoaders: 1
                }
              },
              {
                loader: require.resolve("postcss-loader"),
                options: postCSSLoaderOptions
              }
            ]
          },
          // Adds support for CSS Modules (https://github.com/css-modules/css-modules)
          // using the extension .module.css
          {
            test: /\.module\.css$/,
            use: [
              require.resolve("style-loader"),
              {
                loader: require.resolve("css-loader"),
                options: {
                  importLoaders: 1,
                  modules: true,
                  localIdentName: "[path]__[name]___[local]"
                }
              },
              {
                loader: require.resolve("postcss-loader"),
                options: postCSSLoaderOptions
              }
            ]
          },
          // Allows you to use two kinds of imports for SVG:
          // import logoUrl from './logo.svg'; gives you the URL.
          // import { ReactComponent as Logo } from './logo.svg'; gives you a component.
          {
            test: /\.svg$/,
            use: [
              {
                loader: require.resolve("babel-loader"),
                options: {
                  cacheDirectory: true
                }
              },
              require.resolve("svgr/webpack"),
              {
                loader: require.resolve("file-loader"),
                options: {
                  name: "static/media/[name].[hash:8].[ext]"
                }
              }
            ]
          },
          // "file" loader makes sure those assets get served by WebpackDevServer.
          // When you `import` an asset, you get its (virtual) filename.
          // In production, they would get copied to the `build` folder.
          // This loader doesn't use a "test" so it will catch all modules
          // that fall through the other loaders.
          {
            // Exclude `js` files to keep "css" loader working as it injects
            // its runtime that would otherwise be processed through "file" loader.
            // Also exclude `html` and `json` extensions so they get processed
            // by webpacks internal loaders.
            exclude: [/\.(js|jsx|mjs)$/, /\.html$/, /\.json$/],
            loader: require.resolve("file-loader"),
            options: {
              name: "static/media/[name].[hash:8].[ext]"
            }
          }
        ]
      }
      // ** STOP ** Are you adding a new loader?
      // Make sure to add the new loader(s) before the "file" loader.
    ]
  },
  plugins: [
    // Makes some environment variables available in index.html.
    // The public URL is available as %PUBLIC_URL% in index.html, e.g.:
    // <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
    // In development, this will be an empty string.
    new InterpolateHtmlPlugin(env.raw),
    // Generates an `index.html` file with the <script> injected.
    new HtmlWebpackPlugin({
      inject: true,
      template: paths.appHtml
    }),
    // Add module names to factory functions so they appear in browser profiler.
    new webpack.NamedModulesPlugin(),
    // Makes some environment variables available to the JS code, for example:
    // if (process.env.NODE_ENV === 'development') { ... }. See `./env.js`.
    new webpack.DefinePlugin(env.stringified),
    // This is necessary to emit hot updates (currently CSS only):
    new webpack.HotModuleReplacementPlugin(),
    // Watcher doesn't work well if you mistype casing in a path so we use
    // a plugin that prints an error when you attempt to do this.
    // See https://github.com/facebookincubator/create-react-app/issues/240
    new CaseSensitivePathsPlugin(),
    // If you require a missing module and then `npm install` it, you still have
    // to restart the development server for Webpack to discover it. This plugin
    // makes the discovery automatic so you don't have to restart.
    // See https://github.com/facebookincubator/create-react-app/issues/186
    new WatchMissingNodeModulesPlugin(paths.appNodeModules),
    // Moment.js is an extremely popular library that bundles large locale files
    // by default due to how Webpack interprets its code. This is a practical
    // solution that requires the user to opt into importing specific locales.
    // https://github.com/jmblog/how-to-optimize-momentjs-with-webpack
    // You can remove this if you don't use Moment.js:
    new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/)
  ],
  // Some libraries import Node modules but don't use them in the browser.
  // Tell Webpack to provide empty mocks for them so importing them works.
  node: {
    dgram: "empty",
    fs: "empty",
    net: "empty",
    tls: "empty",
    child_process: "empty"
  },
  // Turn off performance hints during development because we don't do any
  // splitting or minification in interest of speed. These warnings become
  // cumbersome.
  performance: {
    hints: false
  }
};

OBS: Repair the console.log() command in the code above to show what is being loaded.

Running, I´m getting the following result:

$ npm start

> @myorganization/auth@3.0.0 start D:\project\packages\auth
> node scripts/start.js

[ 'D:\\project\\packages\\auth',
  'D:\\project\\packages\\ux',
  'D:\\project\\packages\\auth\\src' ]
Starting the development server...

Failed to compile.

../ux/src/atoms/index.js
Module build failed: Error: No ESLint configuration found.

Commenting the eslint step in webpack.config.dev, I´m getting:

$ npm start

> @myorganization/auth@3.0.0 start D:\project\packages\auth
> node scripts/start.js

[ 'D:\\project\\packages\\auth',
  'D:\\project\\packages\\ux',
  'D:\\project\\packages\\auth\\src' ]
Starting the development server...

Failed to compile.

../ux/src/atoms/ActivityItem/ActivityItem.js
Syntax error: D:\project\packages\ux\src\atoms\ActivityItem\ActivityItem.js: Support for the experimental syntax 'classProperties' isn't currently enabled (34:20):

  32 | class ActivityItem extends Component {
  33 |
> 34 |   static propTypes = {
     |                    ^
  35 |     showHeader: PropTypes.bool,
  36 |     timestamp: PropTypes.number,
  37 |     username: PropTypes.string,

Add @babel/plugin-proposal-class-properties (https://git.io/vb4SL) to the 'plugins' section of your Babel config to enable transformation.

In short, the shared code is not being either transpiled or linted, and that breaks the whole project. The whole project was done using ES6.

Answer 1

As of react-scripts 2.0 they removed support for monorepos ( https://github.com/facebook/create-react-app/issues/1333 ). However if you scroll to the bottom of the issues page you will see a link to react-workspaces. I've not tried it, but it looks promising. (https://github.com/react-workspaces/react-workspaces-playground )