fix: resolve CI build failure (facebook#9640)

Author: mrmckeb

packages/eslint-config-react-app/README.md

@@ -36,10 +36,10 @@ That's it! You can override the settings from `eslint-config-react-app` by editi
 
 This config also ships with optional Jest rules for ESLint (based on [`eslint-plugin-jest`](https://github.com/jest-community/eslint-plugin-jest)).
 
-You'll first need to add the plugin.
+You'll first need to add the ESLint plugin for Jest (if you don't already have it installed).
 
 ```sh
-npm install --save-dev  eslint-plugin-jest@24.x
+npm install --save-dev eslint-plugin-jest@^24.0.0
 ```
 
 You can then enable these rules by adding the Jest config to the `extends` array in your ESLint config.

packages/eslint-config-react-app/base.js

@@ -0,0 +1,47 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+'use strict';
+
+// This file contains the minimum ESLint configuration required for Create
+// React App support, and is used as the `baseConfig` for `eslint-loader`
+// to ensure that user-provided configs don't need this boilerplate.
+
+module.exports = {
+  root: true,
+
+  parser: 'babel-eslint',
+
+  plugins: ['react'],
+
+  env: {
+    browser: true,
+    commonjs: true,
+    es6: true,
+    jest: true,
+    node: true,
+  },
+
+  parserOptions: {
+    ecmaVersion: 2018,
+    sourceType: 'module',
+    ecmaFeatures: {
+      jsx: true,
+    },
+  },
+
+  settings: {
+    react: {
+      version: 'detect',
+    },
+  },
+
+  rules: {
+    'react/jsx-uses-react': 'warn',
+    'react/jsx-uses-vars': 'warn',
+  },
+};

packages/eslint-config-react-app/index.js

@@ -24,33 +24,9 @@
 const restrictedGlobals = require('confusing-browser-globals');
 
 module.exports = {
-  root: true,
+  extends: [require.resolve('./base')],
 
-  parser: 'babel-eslint',
-
-  plugins: ['import', 'flowtype', 'jsx-a11y', 'react', 'react-hooks'],
-
-  env: {
-    browser: true,
-    commonjs: true,
-    es6: true,
-    jest: true,
-    node: true,
-  },
-
-  parserOptions: {
-    ecmaVersion: 2018,
-    sourceType: 'module',
-    ecmaFeatures: {
-      jsx: true,
-    },
-  },
-
-  settings: {
-    react: {
-      version: 'detect',
-    },
-  },
+  plugins: ['import', 'flowtype', 'jsx-a11y', 'react-hooks'],
 
   overrides: [
     {
@@ -269,8 +245,6 @@ module.exports = {
         ignore: [],
       },
     ],
-    'react/jsx-uses-react': 'warn',
-    'react/jsx-uses-vars': 'warn',
     'react/no-danger-with-children': 'warn',
     // Disabled because of undesirable warnings
     // See https://github.com/facebook/create-react-app/issues/5204 for

packages/eslint-config-react-app/package.json

@@ -12,7 +12,9 @@
     "url": "https://github.com/facebook/create-react-app/issues"
   },
   "files": [
-    "index.js"
+    "base.js",
+    "index.js",
+    "jest.js"
   ],
   "peerDependencies": {
     "@typescript-eslint/eslint-plugin": "^4.0.0",

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

@@ -362,6 +362,9 @@ module.exports = function (webpackEnv) {
                 formatter: require.resolve('react-dev-utils/eslintFormatter'),
                 eslintPath: require.resolve('eslint'),
                 resolvePluginsRelativeTo: __dirname,
+                baseConfig: {
+                  extends: [require.resolve('eslint-config-react-app/base')],
+                },
               },
               loader: require.resolve('eslint-loader'),
             },