Adds the PnP plugin for Webpack to find dependencies when working und…

…er PnP

packages/react-scripts/config/webpack.config.dev.js

@@ -10,6 +10,7 @@
 
 const path = require('path');
 const webpack = require('webpack');
+const PnpWebpackPlugin = require('pnp-webpack-plugin');
 const HtmlWebpackPlugin = require('html-webpack-plugin');
 const CaseSensitivePathsPlugin = require('case-sensitive-paths-webpack-plugin');
 const InterpolateHtmlPlugin = require('react-dev-utils/InterpolateHtmlPlugin');
@@ -149,13 +150,29 @@ module.exports = {
       'react-native': 'react-native-web',
     },
     plugins: [
+      // Adds support for installing with Plug'n'Play, leading to faster installs and adding
+      // guards against forgotten dependencies and such.
+      PnpWebpackPlugin,
       // 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]),
     ],
+    // Plug'n'Play relies on symlink for its virtual paths (ie peer dependencies), which Webpack
+    // always resolve to the absolute path on disk by default.
+    symlinks: false,
+  },
+  resolveLoader: {
+    plugins: [
+      // Also related to Plug'n'Play, but this time it tells Webpack to load its loaders
+      // from the current package.
+      PnpWebpackPlugin.moduleLoader(module),
+    ],
+    // Plug'n'Play relies on symlink for its virtual paths (ie peer dependencies), which Webpack
+    // always resolve to the absolute path on disk by default.
+    symlinks: false,
   },
   module: {
     strictExportPresence: true,

packages/react-scripts/config/webpack.config.prod.js

@@ -10,6 +10,7 @@
 
 const path = require('path');
 const webpack = require('webpack');
+const PnpWebpackPlugin = require('pnp-webpack-plugin');
 const HtmlWebpackPlugin = require('html-webpack-plugin');
 const InlineChunkHtmlPlugin = require('react-dev-utils/InlineChunkHtmlPlugin');
 const TerserPlugin = require('terser-webpack-plugin');
@@ -204,13 +205,29 @@ module.exports = {
       'react-native': 'react-native-web',
     },
     plugins: [
+      // Adds support for installing with Plug'n'Play, leading to faster installs and adding
+      // guards against forgotten dependencies and such.
+      PnpWebpackPlugin,
       // 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]),
     ],
+    // Plug'n'Play relies on symlink for its virtual paths (ie peer dependencies), which Webpack
+    // always resolve to the absolute path on disk by default.
+    symlinks: false,
+  },
+  resolveLoader: {
+    plugins: [
+      // Also related to Plug'n'Play, but this time it tells Webpack to load its loaders
+      // from the current package.
+      PnpWebpackPlugin.moduleLoader(module),
+    ],
+    // Plug'n'Play relies on symlink for its virtual paths (ie peer dependencies), which Webpack
+    // always resolve to the absolute path on disk by default.
+    symlinks: false,
   },
   module: {
     strictExportPresence: true,

packages/react-scripts/package.json

@@ -49,6 +49,7 @@
     "jest": "23.6.0",
     "mini-css-extract-plugin": "0.4.3",
     "optimize-css-assets-webpack-plugin": "5.0.1",
+    "pnp-webpack-plugin": "1.0.2",
     "postcss-flexbugs-fixes": "4.1.0",
     "postcss-loader": "3.0.0",
     "postcss-preset-env": "6.0.6",