Support hoisting react-scripts and add require.resolve() to loaders (#2166)

* Support hoisting react-scripts

* require.resolve() loaders and configs

This makes it so that loaders and configs are resolved relative to the config rather than to the app. This seems to make more sense to me.

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

@@ -98,17 +98,6 @@ module.exports = {
       'react-native': 'react-native-web',
     },
   },
-  // @remove-on-eject-begin
-  // Resolve loaders (webpack plugins for CSS, images, transpilation) from the
-  // directory of `react-scripts` itself rather than the project directory.
-  resolveLoader: {
-    modules: [
-      paths.ownNodeModules,
-      // Lerna hoists everything, so we need to look in our app directory
-      paths.appNodeModules,
-    ],
-  },
-  // @remove-on-eject-end
   module: {
     strictExportPresence: true,
     rules: [
@@ -125,13 +114,13 @@ module.exports = {
               formatter: eslintFormatter,
               // @remove-on-eject-begin
               baseConfig: {
-                extends: ['react-app'],
+                extends: [require.resolve('eslint-config-react-app')],
               },
               ignore: false,
               useEslintrc: false,
               // @remove-on-eject-end
             },
-            loader: 'eslint-loader',
+            loader: require.resolve('eslint-loader'),
           },
         ],
         include: paths.appSrc,
@@ -156,7 +145,7 @@ module.exports = {
           /\.jpe?g$/,
           /\.png$/,
         ],
-        loader: 'file-loader',
+        loader: require.resolve('file-loader'),
         options: {
           name: 'static/media/[name].[hash:8].[ext]',
         },
@@ -166,7 +155,7 @@ module.exports = {
       // A missing `test` is equivalent to a match.
       {
         test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
-        loader: 'url-loader',
+        loader: require.resolve('url-loader'),
         options: {
           limit: 10000,
           name: 'static/media/[name].[hash:8].[ext]',
@@ -176,7 +165,7 @@ module.exports = {
       {
         test: /\.(js|jsx)$/,
         include: paths.appSrc,
-        loader: 'babel-loader',
+        loader: require.resolve('babel-loader'),
         options: {
           // @remove-on-eject-begin
           babelrc: false,
@@ -196,15 +185,15 @@ module.exports = {
       {
         test: /\.css$/,
         use: [
-          'style-loader',
+          require.resolve('style-loader'),
           {
-            loader: 'css-loader',
+            loader: require.resolve('css-loader'),
             options: {
               importLoaders: 1,
             },
           },
           {
-            loader: 'postcss-loader',
+            loader: require.resolve('postcss-loader'),
             options: {
               ident: 'postcss', // https://webpack.js.org/guides/migrating/#complex-options
               plugins: () => [

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

@@ -95,17 +95,6 @@ module.exports = {
       'react-native': 'react-native-web',
     },
   },
-  // @remove-on-eject-begin
-  // Resolve loaders (webpack plugins for CSS, images, transpilation) from the
-  // directory of `react-scripts` itself rather than the project directory.
-  resolveLoader: {
-    modules: [
-      paths.ownNodeModules,
-      // Lerna hoists everything, so we need to look in our app directory
-      paths.appNodeModules,
-    ],
-  },
-  // @remove-on-eject-end
   module: {
     strictExportPresence: true,
     rules: [
@@ -124,13 +113,13 @@ module.exports = {
               // TODO: consider separate config for production,
               // e.g. to enable no-console and no-debugger only in production.
               baseConfig: {
-                extends: ['react-app'],
+                extends: [require.resolve('eslint-config-react-app')],
               },
               ignore: false,
               useEslintrc: false,
               // @remove-on-eject-end
             },
-            loader: 'eslint-loader',
+            loader: require.resolve('eslint-loader'),
           },
         ],
         include: paths.appSrc,
@@ -154,7 +143,7 @@ module.exports = {
           /\.jpe?g$/,
           /\.png$/,
         ],
-        loader: 'file-loader',
+        loader: require.resolve('file-loader'),
         options: {
           name: 'static/media/[name].[hash:8].[ext]',
         },
@@ -163,7 +152,7 @@ module.exports = {
       // assets smaller than specified size as data URLs to avoid requests.
       {
         test: [/\.bmp$/, /\.gif$/, /\.jpe?g$/, /\.png$/],
-        loader: 'url-loader',
+        loader: require.resolve('url-loader'),
         options: {
           limit: 10000,
           name: 'static/media/[name].[hash:8].[ext]',
@@ -173,7 +162,7 @@ module.exports = {
       {
         test: /\.(js|jsx)$/,
         include: paths.appSrc,
-        loader: 'babel-loader',
+        loader: require.resolve('babel-loader'),
         // @remove-on-eject-begin
         options: {
           babelrc: false,
@@ -198,17 +187,17 @@ module.exports = {
         loader: ExtractTextPlugin.extract(
           Object.assign(
             {
-              fallback: 'style-loader',
+              fallback: require.resolve('style-loader'),
               use: [
                 {
-                  loader: 'css-loader',
+                  loader: require.resolve('css-loader'),
                   options: {
                     importLoaders: 1,
                     minimize: true,
                   },
                 },
                 {
-                  loader: 'postcss-loader',
+                  loader: require.resolve('postcss-loader'),
                   options: {
                     ident: 'postcss', // https://webpack.js.org/guides/migrating/#complex-options
                     plugins: () => [