From 07c1f954386edb072fd6d5dbc6d55ee5acd83217 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Thu, 3 Jan 2019 16:04:16 +0100
Subject: [PATCH 01/34] Set TS base url based on node_path

---
 packages/react-scripts/config/webpack.config.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index 3696597fb44..fd23e4b6829 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -629,6 +629,8 @@ module.exports = function(webpackEnv) {
             isolatedModules: true,
             noEmit: true,
             jsx: 'preserve',
+            // Typescript expects the baseUrl to be relative from the root directory (e.g. src)
+            baseUrl: process.env.NODE_PATH.replace(paths.appPath + '/', ''),
           },
           reportFiles: [
             '**',

From ec03a780dc79a059037d6ef7ebcc60058544acc4 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Thu, 3 Jan 2019 17:05:53 +0100
Subject: [PATCH 02/34] Remove TS messages for now

---
 .../react-scripts/scripts/utils/verifyTypeScriptSetup.js   | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js b/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
index d8da57a3509..7467a7016c6 100644
--- a/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
+++ b/packages/react-scripts/scripts/utils/verifyTypeScriptSetup.js
@@ -121,13 +121,6 @@ function verifyTypeScriptSetup() {
       value: 'preserve',
       reason: 'JSX is compiled by Babel',
     },
-    // We do not support absolute imports, though this may come as a future
-    // enhancement
-    baseUrl: {
-      value: undefined,
-      reason: 'absolute imports are not supported (yet)',
-    },
-    paths: { value: undefined, reason: 'aliased imports are not supported' },
   };
 
   const formatDiagnosticHost = {

From ebd765076f3c466c4154a7aabd191da9dcaa3f87 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Thu, 3 Jan 2019 17:15:34 +0100
Subject: [PATCH 03/34] Resole baseUrl for tsconfig/jsconfig.json

---
 packages/react-scripts/config/config.js       | 81 +++++++++++++++++++
 packages/react-scripts/config/paths.js        |  3 +
 .../react-scripts/config/webpack.config.js    |  9 +--
 3 files changed, 87 insertions(+), 6 deletions(-)
 create mode 100644 packages/react-scripts/config/config.js

diff --git a/packages/react-scripts/config/config.js b/packages/react-scripts/config/config.js
new file mode 100644
index 00000000000..24e8e08b1cc
--- /dev/null
+++ b/packages/react-scripts/config/config.js
@@ -0,0 +1,81 @@
+// @remove-on-eject-begin
+/**
+ * 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.
+ */
+// @remove-on-eject-end
+'use strict';
+
+const fs = require('fs');
+const chalk = require('chalk');
+const paths = require('./paths');
+
+/**
+ * Get the baseUrl of a compilerOptions object.
+ *
+ * @param {Object} options
+ */
+function getBaseUrl(options = {}) {
+  const baseUrl = options.baseUrl;
+
+  if (!baseUrl) {
+    return null;
+  }
+
+  if (baseUrl !== 'src' && baseUrl !== './src') {
+    console.error(
+      chalk.red.bold(
+        "You tried to set baseUrl to anything other than 'src'. This is not supported in create-react-app and will be ignored."
+      )
+    );
+
+    return null;
+  }
+
+  return 'src';
+}
+
+/**
+ * Get the paths of a compilerOptions object.
+ *
+ * @param {Object} options
+ */
+function getPaths(options = {}) {
+  const paths = options.paths;
+
+  if (!paths) {
+    return [];
+  }
+}
+
+function getConfig() {
+  // Check if TypeScript is setup
+  const useTypeScript = fs.existsSync(paths.appTsConfig);
+  const hasJsConfig = fs.existsSync(paths.appJsConfig);
+
+  let config;
+
+  // If there's a tsconfig.json we assume it's a
+  // Typescript project and set up the config
+  // based on tsconfig.json
+  if (useTypeScript) {
+    config = require(paths.appTsConfig);
+    // Otherwise we'll check if there is jsconfig.json
+    // for non TS projects.
+  } else if (hasJsConfig) {
+    config = require(paths.appJsConfig);
+  }
+
+  config = config || {};
+  const options = config.compilerOptions || {};
+
+  return {
+    paths: getPaths(options),
+    baseUrl: getBaseUrl(options),
+    useTypeScript,
+  };
+}
+
+module.exports = getConfig();
diff --git a/packages/react-scripts/config/paths.js b/packages/react-scripts/config/paths.js
index b719054583b..e5a3e0b5374 100644
--- a/packages/react-scripts/config/paths.js
+++ b/packages/react-scripts/config/paths.js
@@ -84,6 +84,7 @@ module.exports = {
   appPackageJson: resolveApp('package.json'),
   appSrc: resolveApp('src'),
   appTsConfig: resolveApp('tsconfig.json'),
+  appJsConfig: resolveApp('jsconfig.json'),
   yarnLockFile: resolveApp('yarn.lock'),
   testsSetup: resolveModule(resolveApp, 'src/setupTests'),
   proxySetup: resolveApp('src/setupProxy.js'),
@@ -106,6 +107,7 @@ module.exports = {
   appPackageJson: resolveApp('package.json'),
   appSrc: resolveApp('src'),
   appTsConfig: resolveApp('tsconfig.json'),
+  appJsConfig: resolveApp('jsconfig.json'),
   yarnLockFile: resolveApp('yarn.lock'),
   testsSetup: resolveModule(resolveApp, 'src/setupTests'),
   proxySetup: resolveApp('src/setupProxy.js'),
@@ -140,6 +142,7 @@ if (
     appPackageJson: resolveOwn('package.json'),
     appSrc: resolveOwn('template/src'),
     appTsConfig: resolveOwn('template/tsconfig.json'),
+    appJsConfig: resolveOwn('template/jsconfig.json'),
     yarnLockFile: resolveOwn('template/yarn.lock'),
     testsSetup: resolveModule(resolveOwn, 'template/src/setupTests'),
     proxySetup: resolveOwn('template/src/setupProxy.js'),
diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index fd23e4b6829..bc59410fc34 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -30,6 +30,7 @@ const paths = require('./paths');
 const getClientEnvironment = require('./env');
 const ModuleNotFoundPlugin = require('react-dev-utils/ModuleNotFoundPlugin');
 const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin-alt');
+const config = require('./config');
 const typescriptFormatter = require('react-dev-utils/typescriptFormatter');
 // @remove-on-eject-begin
 const getCacheIdentifier = require('react-dev-utils/getCacheIdentifier');
@@ -258,10 +259,7 @@ module.exports = function(webpackEnv) {
       // 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/facebook/create-react-app/issues/253
-      modules: ['node_modules'].concat(
-        // It is guaranteed to exist because we tweak it in `env.js`
-        process.env.NODE_PATH.split(path.delimiter).filter(Boolean)
-      ),
+      modules: ['node_modules'].concat(config.baseUrl ? [config.baseUrl] : []),
       // 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:
@@ -629,8 +627,7 @@ module.exports = function(webpackEnv) {
             isolatedModules: true,
             noEmit: true,
             jsx: 'preserve',
-            // Typescript expects the baseUrl to be relative from the root directory (e.g. src)
-            baseUrl: process.env.NODE_PATH.replace(paths.appPath + '/', ''),
+            baseUrl: config.baseUrl,
           },
           reportFiles: [
             '**',

From 4de79d5e23ee08a9c7780ef6577434a499478d89 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Thu, 3 Jan 2019 18:43:44 +0100
Subject: [PATCH 04/34] Add baseUrl test

---
 .../kitchensink/integration/config.test.js    | 19 +++++++++++++++++++
 .../src/features/config/BaseUrl.test.js       | 19 +++++++++++++++++++
 2 files changed, 38 insertions(+)
 create mode 100644 packages/react-scripts/fixtures/kitchensink/integration/config.test.js
 create mode 100644 packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.test.js

diff --git a/packages/react-scripts/fixtures/kitchensink/integration/config.test.js b/packages/react-scripts/fixtures/kitchensink/integration/config.test.js
new file mode 100644
index 00000000000..6d09b56c481
--- /dev/null
+++ b/packages/react-scripts/fixtures/kitchensink/integration/config.test.js
@@ -0,0 +1,19 @@
+/**
+ * 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.
+ */
+
+import initDOM from './initDOM';
+
+describe('Integration', () => {
+  describe('jsconfig.json/tsconfig.json', () => {
+    it('Supports setting baseUrl to src', async () => {
+      const doc = await initDOM('base-url');
+
+      expect(doc.getElementById('feature-base-url').childElementCount).toBe(4);
+      doc.defaultView.close();
+    });
+  });
+});
diff --git a/packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.test.js b/packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.test.js
new file mode 100644
index 00000000000..378ec9d2fa9
--- /dev/null
+++ b/packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.test.js
@@ -0,0 +1,19 @@
+/**
+ * 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.
+ */
+
+import React from 'react';
+import ReactDOM from 'react-dom';
+import BaseUrl from './BaseUrl';
+
+describe('baseUrl', () => {
+  it('renders without crashing', () => {
+    const div = document.createElement('div');
+    return new Promise(resolve => {
+      ReactDOM.render(<BaseUrl onReady={resolve} />, div);
+    });
+  });
+});

From 839a2a33241863960e188c6414a14c8f9f56328e Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Thu, 3 Jan 2019 19:29:47 +0100
Subject: [PATCH 05/34] Add jsconfig.json to kitchensink

---
 packages/react-scripts/fixtures/kitchensink/jsconfig.json | 5 +++++
 tasks/e2e-kitchensink.sh                                  | 6 +-----
 2 files changed, 6 insertions(+), 5 deletions(-)
 create mode 100644 packages/react-scripts/fixtures/kitchensink/jsconfig.json

diff --git a/packages/react-scripts/fixtures/kitchensink/jsconfig.json b/packages/react-scripts/fixtures/kitchensink/jsconfig.json
new file mode 100644
index 00000000000..ec2332eb49c
--- /dev/null
+++ b/packages/react-scripts/fixtures/kitchensink/jsconfig.json
@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "baseUrl": "src"
+  }
+}
diff --git a/tasks/e2e-kitchensink.sh b/tasks/e2e-kitchensink.sh
index 2b886a1791a..e38da60c8df 100755
--- a/tasks/e2e-kitchensink.sh
+++ b/tasks/e2e-kitchensink.sh
@@ -122,7 +122,6 @@ npm link "$temp_module_path/node_modules/test-integrity"
 
 # Test the build
 REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
-  NODE_PATH=src \
   PUBLIC_URL=http://www.example.org/spa/ \
   yarn build
 
@@ -134,7 +133,6 @@ exists build/static/js/main.*.js
 # https://facebook.github.io/jest/docs/en/troubleshooting.html#tests-are-extremely-slow-on-docker-and-or-continuous-integration-ci-server
 REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
   CI=true \
-  NODE_PATH=src \
   NODE_ENV=test \
   yarn test --no-cache --runInBand --testPathPattern=src
 
@@ -142,21 +140,19 @@ REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
 tmp_server_log=`mktemp`
 PORT=3001 \
   REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
-  NODE_PATH=src \
   nohup yarn start &>$tmp_server_log &
 grep -q 'You can now view' <(tail -f $tmp_server_log)
 
 # Test "development" environment
 E2E_URL="http://localhost:3001" \
   REACT_APP_SHELL_ENV_MESSAGE=fromtheshell \
-  CI=true NODE_PATH=src \
+  CI=true \
   NODE_ENV=development \
   BABEL_ENV=test \
   node_modules/.bin/jest --no-cache --runInBand --config='jest.integration.config.js'
 # Test "production" environment
 E2E_FILE=./build/index.html \
   CI=true \
-  NODE_PATH=src \
   NODE_ENV=production \
   BABEL_ENV=test \
   PUBLIC_URL=http://www.example.org/spa/ \

From 91f7794deb4b23d17595c0a8fbe9a4190cf26c94 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Thu, 3 Jan 2019 20:05:15 +0100
Subject: [PATCH 06/34] Add BaseUrl component

---
 .../src/features/config/BaseUrl.js            | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.js

diff --git a/packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.js b/packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.js
new file mode 100644
index 00000000000..c17c750be6a
--- /dev/null
+++ b/packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.js
@@ -0,0 +1,41 @@
+i;
+/**
+ * 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.
+ */
+
+import React, { Component } from 'react';
+import PropTypes from 'prop-types';
+import load from 'absoluteLoad';
+
+export default class extends Component {
+  static propTypes = {
+    onReady: PropTypes.func.isRequired,
+  };
+
+  constructor(props) {
+    super(props);
+    this.state = { users: [] };
+  }
+
+  async componentDidMount() {
+    const users = load();
+    this.setState({ users });
+  }
+
+  componentDidUpdate() {
+    this.props.onReady();
+  }
+
+  render() {
+    return (
+      <div id="feature-base-url">
+        {this.state.users.map(user => (
+          <div key={user.id}>{user.name}</div>
+        ))}
+      </div>
+    );
+  }
+}

From be875380b249636910e09ccf475b25db22fe410f Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Thu, 3 Jan 2019 20:55:55 +0100
Subject: [PATCH 07/34] Add baseUrl as modulePath for jest

---
 packages/react-scripts/scripts/utils/createJestConfig.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/packages/react-scripts/scripts/utils/createJestConfig.js b/packages/react-scripts/scripts/utils/createJestConfig.js
index 58c2ad48812..1bd5725a4e5 100644
--- a/packages/react-scripts/scripts/utils/createJestConfig.js
+++ b/packages/react-scripts/scripts/utils/createJestConfig.js
@@ -10,6 +10,7 @@
 const fs = require('fs');
 const chalk = require('chalk');
 const paths = require('../../config/paths');
+const jsConfig = require('../../config/config');
 
 module.exports = (resolve, rootDir, isEjecting) => {
   // Use this instead of `paths.testsSetup` to avoid putting
@@ -57,6 +58,7 @@ module.exports = (resolve, rootDir, isEjecting) => {
       '[/\\\\]node_modules[/\\\\].+\\.(js|jsx|ts|tsx)$',
       '^.+\\.module\\.(css|sass|scss)$',
     ],
+    modulePaths: jsConfig.baseUrl ? ['<rootDir>/' + jsConfig.baseUrl] : [],
     moduleNameMapper: {
       '^react-native$': 'react-native-web',
       '^.+\\.module\\.(css|sass|scss)$': 'identity-obj-proxy',

From e0d3ebf84242bafc468f5cc6655f1110c9539f70 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 19:49:24 +0100
Subject: [PATCH 08/34] =?UTF-8?q?Remove=20NODE=5FPATH=20resolving=20and=20?=
 =?UTF-8?q?inform=20user=20about=20it=E2=80=99s=20deprecation.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 packages/react-scripts/config/env.js | 21 +++++++--------------
 1 file changed, 7 insertions(+), 14 deletions(-)

diff --git a/packages/react-scripts/config/env.js b/packages/react-scripts/config/env.js
index 7565cecd001..61e2992cc2d 100644
--- a/packages/react-scripts/config/env.js
+++ b/packages/react-scripts/config/env.js
@@ -48,21 +48,14 @@ dotenvFiles.forEach(dotenvFile => {
   }
 });
 
-// We support resolving modules according to `NODE_PATH`.
+// We used to support resolving modules according to `NODE_PATH`.
+// This now has been deprecated in favor of jsconfig/tsconfig.json
 // This lets you use absolute paths in imports inside large monorepos:
-// https://github.com/facebook/create-react-app/issues/253.
-// It works similar to `NODE_PATH` in Node itself:
-// https://nodejs.org/api/modules.html#modules_loading_from_the_global_folders
-// Note that unlike in Node, only *relative* paths from `NODE_PATH` are honored.
-// Otherwise, we risk importing Node.js core modules into an app instead of Webpack shims.
-// https://github.com/facebook/create-react-app/issues/1023#issuecomment-265344421
-// We also resolve them to make sure all tools using them work consistently.
-const appDirectory = fs.realpathSync(process.cwd());
-process.env.NODE_PATH = (process.env.NODE_PATH || '')
-  .split(path.delimiter)
-  .filter(folder => folder && !path.isAbsolute(folder))
-  .map(folder => path.resolve(appDirectory, folder))
-  .join(path.delimiter);
+if (process.env.NODE_PATH) {
+  console.log(
+    'Setting NODE_PATH to resolves modules absolutely has been deprecated in favor of setting baseUrl in jsconfig.json (or tsconfig.json if you are using Typescript) to achieve the same behaviour.'
+  );
+}
 
 // Grab NODE_ENV and REACT_APP_* environment variables and prepare them to be
 // injected into the application via DefinePlugin in Webpack configuration.

From 5d67018bdaff4f68da1fff3f40e43e03a6f388a7 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 20:01:03 +0100
Subject: [PATCH 09/34] Remove unused variable

---
 packages/react-scripts/config/env.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/react-scripts/config/env.js b/packages/react-scripts/config/env.js
index 61e2992cc2d..4c0fd54656a 100644
--- a/packages/react-scripts/config/env.js
+++ b/packages/react-scripts/config/env.js
@@ -9,7 +9,6 @@
 'use strict';
 
 const fs = require('fs');
-const path = require('path');
 const paths = require('./paths');
 
 // Make sure that including paths.js after env.js will read .env variables.

From bb49cf351a7f3bbe02b13d72207163f5d99fceb0 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 20:08:58 +0100
Subject: [PATCH 10/34] Remove accident typo

---
 .../fixtures/kitchensink/src/features/config/BaseUrl.js          | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.js b/packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.js
index c17c750be6a..818d4db271b 100644
--- a/packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.js
+++ b/packages/react-scripts/fixtures/kitchensink/src/features/config/BaseUrl.js
@@ -1,4 +1,3 @@
-i;
 /**
  * Copyright (c) 2015-present, Facebook, Inc.
  *

From f5821c21785eda13586f61c3349c9df2c49f8f4e Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 20:27:00 +0100
Subject: [PATCH 11/34] Remove unused tests & properly load baseUrl test

---
 .../kitchensink/integration/env.test.js       |  7 ----
 .../fixtures/kitchensink/src/App.js           |  4 +-
 .../kitchensink/src/features/env/NodePath.js  | 40 -------------------
 .../src/features/env/NodePath.test.js         | 19 ---------
 4 files changed, 2 insertions(+), 68 deletions(-)
 delete mode 100644 packages/react-scripts/fixtures/kitchensink/src/features/env/NodePath.js
 delete mode 100644 packages/react-scripts/fixtures/kitchensink/src/features/env/NodePath.test.js

diff --git a/packages/react-scripts/fixtures/kitchensink/integration/env.test.js b/packages/react-scripts/fixtures/kitchensink/integration/env.test.js
index 79de16706dc..90e0e631e88 100644
--- a/packages/react-scripts/fixtures/kitchensink/integration/env.test.js
+++ b/packages/react-scripts/fixtures/kitchensink/integration/env.test.js
@@ -37,13 +37,6 @@ describe('Integration', () => {
       doc.defaultView.close();
     });
 
-    it('NODE_PATH', async () => {
-      const doc = await initDOM('node-path');
-
-      expect(doc.getElementById('feature-node-path').childElementCount).toBe(4);
-      doc.defaultView.close();
-    });
-
     it('PUBLIC_URL', async () => {
       const doc = await initDOM('public-url');
 
diff --git a/packages/react-scripts/fixtures/kitchensink/src/App.js b/packages/react-scripts/fixtures/kitchensink/src/App.js
index 380a49fc639..66387d0397a 100644
--- a/packages/react-scripts/fixtures/kitchensink/src/App.js
+++ b/packages/react-scripts/fixtures/kitchensink/src/App.js
@@ -149,8 +149,8 @@ class App extends Component {
           this.setFeature(f.default)
         );
         break;
-      case 'node-path':
-        import('./features/env/NodePath').then(f => this.setFeature(f.default));
+      case 'base-url':
+        import('./features/env/BaseUrl').then(f => this.setFeature(f.default));
         break;
       case 'no-ext-inclusion':
         import('./features/webpack/NoExtInclusion').then(f =>
diff --git a/packages/react-scripts/fixtures/kitchensink/src/features/env/NodePath.js b/packages/react-scripts/fixtures/kitchensink/src/features/env/NodePath.js
deleted file mode 100644
index e89228e20b0..00000000000
--- a/packages/react-scripts/fixtures/kitchensink/src/features/env/NodePath.js
+++ /dev/null
@@ -1,40 +0,0 @@
-/**
- * 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.
- */
-
-import React, { Component } from 'react';
-import PropTypes from 'prop-types';
-import load from 'absoluteLoad';
-
-export default class extends Component {
-  static propTypes = {
-    onReady: PropTypes.func.isRequired,
-  };
-
-  constructor(props) {
-    super(props);
-    this.state = { users: [] };
-  }
-
-  async componentDidMount() {
-    const users = load();
-    this.setState({ users });
-  }
-
-  componentDidUpdate() {
-    this.props.onReady();
-  }
-
-  render() {
-    return (
-      <div id="feature-node-path">
-        {this.state.users.map(user => (
-          <div key={user.id}>{user.name}</div>
-        ))}
-      </div>
-    );
-  }
-}
diff --git a/packages/react-scripts/fixtures/kitchensink/src/features/env/NodePath.test.js b/packages/react-scripts/fixtures/kitchensink/src/features/env/NodePath.test.js
deleted file mode 100644
index 1de025d2f2f..00000000000
--- a/packages/react-scripts/fixtures/kitchensink/src/features/env/NodePath.test.js
+++ /dev/null
@@ -1,19 +0,0 @@
-/**
- * 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.
- */
-
-import React from 'react';
-import ReactDOM from 'react-dom';
-import NodePath from './NodePath';
-
-describe('NODE_PATH', () => {
-  it('renders without crashing', () => {
-    const div = document.createElement('div');
-    return new Promise(resolve => {
-      ReactDOM.render(<NodePath onReady={resolve} />, div);
-    });
-  });
-});

From 832cad2d6408be4f62f0ac820e19643d702a8c7c Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 20:44:57 +0100
Subject: [PATCH 12/34] Fix wrong path to BaseUrl test

---
 packages/react-scripts/fixtures/kitchensink/src/App.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/react-scripts/fixtures/kitchensink/src/App.js b/packages/react-scripts/fixtures/kitchensink/src/App.js
index 66387d0397a..76a4a79fe4b 100644
--- a/packages/react-scripts/fixtures/kitchensink/src/App.js
+++ b/packages/react-scripts/fixtures/kitchensink/src/App.js
@@ -150,7 +150,9 @@ class App extends Component {
         );
         break;
       case 'base-url':
-        import('./features/env/BaseUrl').then(f => this.setFeature(f.default));
+        import('./features/config/BaseUrl').then(f =>
+          this.setFeature(f.default)
+        );
         break;
       case 'no-ext-inclusion':
         import('./features/webpack/NoExtInclusion').then(f =>

From 401b500e7543b529219763eb97b7bca7336082c2 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 22:38:18 +0100
Subject: [PATCH 13/34] Add support for aliasing @ to src

---
 packages/react-scripts/config/config.js       | 43 ++++++++++++++++---
 .../react-scripts/config/webpack.config.js    |  1 +
 .../fixtures/kitchensink/jsconfig.json        |  5 ++-
 .../fixtures/kitchensink/src/App.js           |  3 ++
 .../kitchensink/src/features/config/Alias.js  | 40 +++++++++++++++++
 .../src/features/config/Alias.test.js         | 19 ++++++++
 6 files changed, 103 insertions(+), 8 deletions(-)
 create mode 100644 packages/react-scripts/fixtures/kitchensink/src/features/config/Alias.js
 create mode 100644 packages/react-scripts/fixtures/kitchensink/src/features/config/Alias.test.js

diff --git a/packages/react-scripts/config/config.js b/packages/react-scripts/config/config.js
index 24e8e08b1cc..f80c3e0cdfb 100644
--- a/packages/react-scripts/config/config.js
+++ b/packages/react-scripts/config/config.js
@@ -9,9 +9,12 @@
 'use strict';
 
 const fs = require('fs');
+const path = require('path');
 const chalk = require('chalk');
 const paths = require('./paths');
 
+const appDirectory = fs.realpathSync(process.cwd());
+
 /**
  * Get the baseUrl of a compilerOptions object.
  *
@@ -34,20 +37,46 @@ function getBaseUrl(options = {}) {
     return null;
   }
 
-  return 'src';
+  return path.resolve(appDirectory, 'src');
 }
 
 /**
- * Get the paths of a compilerOptions object.
+ * Get the alias of a compilerOptions object.
  *
  * @param {Object} options
  */
-function getPaths(options = {}) {
-  const paths = options.paths;
+function getAlias(options = {}) {
+  const paths = options.paths || {};
+
+  const alias = paths['@'];
+
+  const others = Object.keys(paths).filter(function(value) {
+    return value !== '@';
+  });
+
+  if (others.length) {
+    console.error(
+      chalk.red.bold(
+        'You tried to set one or more paths with an alias other than "@", this is currently not supported in create-react-app and will be ignored.'
+      )
+    );
+  }
 
-  if (!paths) {
-    return [];
+  if (!alias) {
+    return {};
   }
+
+  if (alias.toString() !== 'src') {
+    console.error(
+      chalk.red.bold(
+        "You tried to set a path with alias '@' to anything other than ['src']. This is not supported in create-react-app and will be ignored."
+      )
+    );
+  }
+
+  return {
+    '@': path.resolve(appDirectory, 'src'),
+  };
 }
 
 function getConfig() {
@@ -72,7 +101,7 @@ function getConfig() {
   const options = config.compilerOptions || {};
 
   return {
-    paths: getPaths(options),
+    alias: getAlias(options),
     baseUrl: getBaseUrl(options),
     useTypeScript,
   };
diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index bc59410fc34..21d3d2d8412 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -273,6 +273,7 @@ module.exports = function(webpackEnv) {
         // 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',
+        ...config.alias,
       },
       plugins: [
         // Adds support for installing with Plug'n'Play, leading to faster installs and adding
diff --git a/packages/react-scripts/fixtures/kitchensink/jsconfig.json b/packages/react-scripts/fixtures/kitchensink/jsconfig.json
index ec2332eb49c..f0d9b148297 100644
--- a/packages/react-scripts/fixtures/kitchensink/jsconfig.json
+++ b/packages/react-scripts/fixtures/kitchensink/jsconfig.json
@@ -1,5 +1,8 @@
 {
   "compilerOptions": {
-    "baseUrl": "src"
+    "baseUrl": "src",
+    "paths": {
+      "@": ["src"]
+    }
   }
 }
diff --git a/packages/react-scripts/fixtures/kitchensink/src/App.js b/packages/react-scripts/fixtures/kitchensink/src/App.js
index 76a4a79fe4b..82fe9da3779 100644
--- a/packages/react-scripts/fixtures/kitchensink/src/App.js
+++ b/packages/react-scripts/fixtures/kitchensink/src/App.js
@@ -154,6 +154,9 @@ class App extends Component {
           this.setFeature(f.default)
         );
         break;
+      case 'alias':
+        import('./features/config/Alias').then(f => this.setFeature(f.default));
+        break;
       case 'no-ext-inclusion':
         import('./features/webpack/NoExtInclusion').then(f =>
           this.setFeature(f.default)
diff --git a/packages/react-scripts/fixtures/kitchensink/src/features/config/Alias.js b/packages/react-scripts/fixtures/kitchensink/src/features/config/Alias.js
new file mode 100644
index 00000000000..f803de8ef6c
--- /dev/null
+++ b/packages/react-scripts/fixtures/kitchensink/src/features/config/Alias.js
@@ -0,0 +1,40 @@
+/**
+ * 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.
+ */
+
+import React, { Component } from 'react';
+import PropTypes from 'prop-types';
+import load from '@/absoluteLoad';
+
+export default class extends Component {
+  static propTypes = {
+    onReady: PropTypes.func.isRequired,
+  };
+
+  constructor(props) {
+    super(props);
+    this.state = { users: [] };
+  }
+
+  async componentDidMount() {
+    const users = load();
+    this.setState({ users });
+  }
+
+  componentDidUpdate() {
+    this.props.onReady();
+  }
+
+  render() {
+    return (
+      <div id="feature-alias">
+        {this.state.users.map(user => (
+          <div key={user.id}>{user.name}</div>
+        ))}
+      </div>
+    );
+  }
+}
diff --git a/packages/react-scripts/fixtures/kitchensink/src/features/config/Alias.test.js b/packages/react-scripts/fixtures/kitchensink/src/features/config/Alias.test.js
new file mode 100644
index 00000000000..94288459b25
--- /dev/null
+++ b/packages/react-scripts/fixtures/kitchensink/src/features/config/Alias.test.js
@@ -0,0 +1,19 @@
+/**
+ * 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.
+ */
+
+import React from 'react';
+import ReactDOM from 'react-dom';
+import Alias from './Alias';
+
+describe('alias', () => {
+  it('renders without crashing', () => {
+    const div = document.createElement('div');
+    return new Promise(resolve => {
+      ReactDOM.render(<Alias onReady={resolve} />, div);
+    });
+  });
+});

From 234e361eb2fb8f8c70e5b897a68a42e96a35b0cc Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 22:51:43 +0100
Subject: [PATCH 14/34] Add integration test for alias

---
 .../fixtures/kitchensink/integration/config.test.js        | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/packages/react-scripts/fixtures/kitchensink/integration/config.test.js b/packages/react-scripts/fixtures/kitchensink/integration/config.test.js
index 6d09b56c481..07831724aa4 100644
--- a/packages/react-scripts/fixtures/kitchensink/integration/config.test.js
+++ b/packages/react-scripts/fixtures/kitchensink/integration/config.test.js
@@ -15,5 +15,12 @@ describe('Integration', () => {
       expect(doc.getElementById('feature-base-url').childElementCount).toBe(4);
       doc.defaultView.close();
     });
+
+    it('Supports setting @ as alias to src', async () => {
+      const doc = await initDOM('alias');
+
+      expect(doc.getElementById('feature-alias').childElementCount).toBe(4);
+      doc.defaultView.close();
+    });
   });
 });

From 97ea8541a605d2db806aed68a54a8a3424667ab3 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 23:09:31 +0100
Subject: [PATCH 15/34] Log to debug tests

---
 packages/react-scripts/config/webpack.config.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index 21d3d2d8412..c35e4833f04 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -31,6 +31,7 @@ const getClientEnvironment = require('./env');
 const ModuleNotFoundPlugin = require('react-dev-utils/ModuleNotFoundPlugin');
 const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin-alt');
 const config = require('./config');
+console.log(JSON.stringify(config));
 const typescriptFormatter = require('react-dev-utils/typescriptFormatter');
 // @remove-on-eject-begin
 const getCacheIdentifier = require('react-dev-utils/getCacheIdentifier');

From 2aa5605ec3f11858c9f9732bf1fb3aa88e57a87c Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 23:34:17 +0100
Subject: [PATCH 16/34] Allow setting the baseUrl to node_modules

---
 packages/react-scripts/config/config.js | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/packages/react-scripts/config/config.js b/packages/react-scripts/config/config.js
index f80c3e0cdfb..2b8fd123b47 100644
--- a/packages/react-scripts/config/config.js
+++ b/packages/react-scripts/config/config.js
@@ -13,7 +13,12 @@ const path = require('path');
 const chalk = require('chalk');
 const paths = require('./paths');
 
-const appDirectory = fs.realpathSync(process.cwd());
+function isValidPath(path) {
+  return (
+    paths.relative(paths.appSrc, path) === '.' ||
+    paths.relative(paths.appNodeModules, path) === '.'
+  );
+}
 
 /**
  * Get the baseUrl of a compilerOptions object.
@@ -27,17 +32,19 @@ function getBaseUrl(options = {}) {
     return null;
   }
 
-  if (baseUrl !== 'src' && baseUrl !== './src') {
+  const baseUrlResolved = path.resolve(appDirectory, baseUrl);
+
+  if (!isValidPath) {
     console.error(
       chalk.red.bold(
-        "You tried to set baseUrl to anything other than 'src'. This is not supported in create-react-app and will be ignored."
+        "You tried to set baseUrl to anything other than 'src' or 'node_modules'.This is not supported in create-react-app and will be ignored."
       )
     );
 
     return null;
   }
 
-  return path.resolve(appDirectory, 'src');
+  return path.resolve(paths.appDirectory, 'src');
 }
 
 /**
@@ -48,8 +55,6 @@ function getBaseUrl(options = {}) {
 function getAlias(options = {}) {
   const paths = options.paths || {};
 
-  const alias = paths['@'];
-
   const others = Object.keys(paths).filter(function(value) {
     return value !== '@';
   });

From a0ed8582c44c5bfff1548ec7e80f5c34c4eb3a48 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 23:35:18 +0100
Subject: [PATCH 17/34] Remove unnecessary prefix for Jest module paths

---
 packages/react-scripts/scripts/utils/createJestConfig.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/react-scripts/scripts/utils/createJestConfig.js b/packages/react-scripts/scripts/utils/createJestConfig.js
index 1bd5725a4e5..a4570a3421b 100644
--- a/packages/react-scripts/scripts/utils/createJestConfig.js
+++ b/packages/react-scripts/scripts/utils/createJestConfig.js
@@ -58,7 +58,7 @@ module.exports = (resolve, rootDir, isEjecting) => {
       '[/\\\\]node_modules[/\\\\].+\\.(js|jsx|ts|tsx)$',
       '^.+\\.module\\.(css|sass|scss)$',
     ],
-    modulePaths: jsConfig.baseUrl ? ['<rootDir>/' + jsConfig.baseUrl] : [],
+    modulePaths: jsConfig.baseUrl ? [jsConfig.baseUrl] : [],
     moduleNameMapper: {
       '^react-native$': 'react-native-web',
       '^.+\\.module\\.(css|sass|scss)$': 'identity-obj-proxy',

From e52182dd17774a40e6cad844f29eddc1a38d8110 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 23:37:56 +0100
Subject: [PATCH 18/34] Whoops.

---
 packages/react-scripts/config/config.js | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/packages/react-scripts/config/config.js b/packages/react-scripts/config/config.js
index 2b8fd123b47..3d4be0ebf1f 100644
--- a/packages/react-scripts/config/config.js
+++ b/packages/react-scripts/config/config.js
@@ -55,6 +55,8 @@ function getBaseUrl(options = {}) {
 function getAlias(options = {}) {
   const paths = options.paths || {};
 
+  const alias = paths['@'];
+
   const others = Object.keys(paths).filter(function(value) {
     return value !== '@';
   });

From bf5329f837a531b0b01695a54f4b47c5b18207e8 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 23:39:41 +0100
Subject: [PATCH 19/34] Call isValidPath method to check if the baseUrl is
 valid

---
 packages/react-scripts/config/config.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/react-scripts/config/config.js b/packages/react-scripts/config/config.js
index 3d4be0ebf1f..4e254819973 100644
--- a/packages/react-scripts/config/config.js
+++ b/packages/react-scripts/config/config.js
@@ -32,9 +32,9 @@ function getBaseUrl(options = {}) {
     return null;
   }
 
-  const baseUrlResolved = path.resolve(appDirectory, baseUrl);
+  const baseUrlResolved = path.resolve(paths.appDirectory, baseUrl);
 
-  if (!isValidPath) {
+  if (!isValidPath(baseUrlResolved)) {
     console.error(
       chalk.red.bold(
         "You tried to set baseUrl to anything other than 'src' or 'node_modules'.This is not supported in create-react-app and will be ignored."

From 2c19adc5e67953c7bb5c67f1c79d5862a394fa7a Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 23:40:05 +0100
Subject: [PATCH 20/34] Use appDirectory from paths

---
 packages/react-scripts/config/config.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/react-scripts/config/config.js b/packages/react-scripts/config/config.js
index 4e254819973..7e30130ec26 100644
--- a/packages/react-scripts/config/config.js
+++ b/packages/react-scripts/config/config.js
@@ -82,7 +82,7 @@ function getAlias(options = {}) {
   }
 
   return {
-    '@': path.resolve(appDirectory, 'src'),
+    '@': path.resolve(paths.appDirectory, 'src'),
   };
 }
 

From ac8dd39019ddcdc841c663cf2c35201780ea6f7a Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Sun, 6 Jan 2019 23:42:30 +0100
Subject: [PATCH 21/34] Throw error if there are both a tsconfig.json and
 jsconfig.json file

---
 packages/react-scripts/config/config.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/packages/react-scripts/config/config.js b/packages/react-scripts/config/config.js
index 7e30130ec26..ba9d8c02842 100644
--- a/packages/react-scripts/config/config.js
+++ b/packages/react-scripts/config/config.js
@@ -91,6 +91,12 @@ function getConfig() {
   const useTypeScript = fs.existsSync(paths.appTsConfig);
   const hasJsConfig = fs.existsSync(paths.appJsConfig);
 
+  if (useTypeScript && hasJsConfig) {
+    throw new Error(
+      'You have both a tsconfig.json and a jsconfig.json. If you are using Typescript please remove your jsconfig.json file.'
+    );
+  }
+
   let config;
 
   // If there's a tsconfig.json we assume it's a

From a9b60b11c1c6e30b19b71875cef9e83884b1e27a Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 09:27:26 +0100
Subject: [PATCH 22/34] Add better path checking & add support for different
 aliases for src

---
 packages/react-scripts/config/config.js       | 123 ++++++++++--------
 .../react-scripts/config/webpack.config.js    |   6 +-
 .../scripts/utils/createJestConfig.js         |   5 +-
 3 files changed, 80 insertions(+), 54 deletions(-)

diff --git a/packages/react-scripts/config/config.js b/packages/react-scripts/config/config.js
index ba9d8c02842..f16f69643f7 100644
--- a/packages/react-scripts/config/config.js
+++ b/packages/react-scripts/config/config.js
@@ -13,38 +13,40 @@ const path = require('path');
 const chalk = require('chalk');
 const paths = require('./paths');
 
-function isValidPath(path) {
-  return (
-    paths.relative(paths.appSrc, path) === '.' ||
-    paths.relative(paths.appNodeModules, path) === '.'
-  );
-}
-
 /**
  * Get the baseUrl of a compilerOptions object.
  *
  * @param {Object} options
  */
-function getBaseUrl(options = {}) {
+function getAdditionalModulePath(options = {}) {
   const baseUrl = options.baseUrl;
 
-  if (!baseUrl) {
+  // We need to explicitly check for null and undefined (and not a falsy value) because
+  // TypeScript treats an empty string as `.`.
+  if (baseUrl == null) {
     return null;
   }
 
-  const baseUrlResolved = path.resolve(paths.appDirectory, baseUrl);
-
-  if (!isValidPath(baseUrlResolved)) {
-    console.error(
-      chalk.red.bold(
-        "You tried to set baseUrl to anything other than 'src' or 'node_modules'.This is not supported in create-react-app and will be ignored."
-      )
-    );
+  const baseUrlResolved = path.resolve(paths.appPath, baseUrl);
 
+  // We don't need to do anything if `baseUrl` is set to `node_modules`. This is
+  // the default behavior.
+  if (path.relative(paths.appNodeModules, baseUrlResolved) === '') {
     return null;
   }
 
-  return path.resolve(paths.appDirectory, 'src');
+  // Allow the user set the `baseUrl` to `appSrc`.
+  if (path.relative(paths.appSrc, baseUrlResolved) === '') {
+    return paths.appSrc;
+  }
+
+  // Otherwise, throw an error.
+  throw new Error(
+    chalk.red.bold(
+      "Your project's `baseUrl` can only be set to `src` or `node_modules`." +
+        ' Create React App does not support other values at this time.'
+    )
+  );
 }
 
 /**
@@ -52,38 +54,52 @@ function getBaseUrl(options = {}) {
  *
  * @param {Object} options
  */
-function getAlias(options = {}) {
-  const paths = options.paths || {};
-
-  const alias = paths['@'];
-
-  const others = Object.keys(paths).filter(function(value) {
-    return value !== '@';
-  });
-
-  if (others.length) {
-    console.error(
-      chalk.red.bold(
-        'You tried to set one or more paths with an alias other than "@", this is currently not supported in create-react-app and will be ignored.'
-      )
-    );
-  }
-
-  if (!alias) {
-    return {};
-  }
-
-  if (alias.toString() !== 'src') {
-    console.error(
-      chalk.red.bold(
-        "You tried to set a path with alias '@' to anything other than ['src']. This is not supported in create-react-app and will be ignored."
-      )
-    );
-  }
+function getAliases(options = {}) {
+  // This is an object with the alias as key
+  // and an array of paths as value.
+  // e.g. '@': ['src']
+  const aliases = options.paths || {};
+
+  return Object.keys(aliases).reduce(function(prev, alias) {
+    // Value contains the paths of the alias.
+    const value = aliases[alias];
+
+    // The value should be an array but we have to verify
+    // that because it's user input.
+    if (!Array.isArray(value) || value.length > 1) {
+      throw new Error(
+        chalk.red.bold(
+          "Your project's `alias` can only be set to an array containing `src`." +
+            ' Create React App does not support other values at this time.'
+        )
+      );
+    }
+
+    const aliasPath = value[0];
+    const resolvedAliasPath = path.resolve(paths.appPath, aliasPath);
+
+    if (path.relative(paths.appSrc, resolvedAliasPath) !== '') {
+      throw new Error(
+        chalk.red.bold(
+          "Your project's `alias` can only be set to ['src']." +
+            ' Create React App does not support other values at this time.'
+        )
+      );
+    }
+
+    prev[alias] = resolvedAliasPath;
+    return prev;
+  }, {});
+}
 
-  return {
-    '@': path.resolve(paths.appDirectory, 'src'),
-  };
+function getJestAliases(aliases) {
+  return Object.keys(aliases).reduce(function(prev, alias) {
+    const aliasPath = aliases[alias];
+    const relativeAliasPath = path.relative(paths.appPath, aliasPath);
+    const match = alias + '(.*)$';
+    const target = '<rootDir>/' + relativeAliasPath + '/$1';
+    prev[match] = target;
+  }, {});
 }
 
 function getConfig() {
@@ -113,9 +129,14 @@ function getConfig() {
   config = config || {};
   const options = config.compilerOptions || {};
 
+  const aliases = getAliases(options);
+  const jestAliases = getJestAliases(aliases);
+  const additionalModulePath = getAdditionalModulePath(options);
+
   return {
-    alias: getAlias(options),
-    baseUrl: getBaseUrl(options),
+    aliases,
+    jestAliases,
+    additionalModulePath,
     useTypeScript,
   };
 }
diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index c35e4833f04..219bd5ce537 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -260,7 +260,9 @@ module.exports = function(webpackEnv) {
       // 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/facebook/create-react-app/issues/253
-      modules: ['node_modules'].concat(config.baseUrl ? [config.baseUrl] : []),
+      modules: ['node_modules'].concat(
+        config.additionalModulePath ? [config.additionalModulePath] : []
+      ),
       // 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:
@@ -274,7 +276,7 @@ module.exports = function(webpackEnv) {
         // 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',
-        ...config.alias,
+        ...config.aliases,
       },
       plugins: [
         // Adds support for installing with Plug'n'Play, leading to faster installs and adding
diff --git a/packages/react-scripts/scripts/utils/createJestConfig.js b/packages/react-scripts/scripts/utils/createJestConfig.js
index a4570a3421b..28c5cbf0a03 100644
--- a/packages/react-scripts/scripts/utils/createJestConfig.js
+++ b/packages/react-scripts/scripts/utils/createJestConfig.js
@@ -58,10 +58,13 @@ module.exports = (resolve, rootDir, isEjecting) => {
       '[/\\\\]node_modules[/\\\\].+\\.(js|jsx|ts|tsx)$',
       '^.+\\.module\\.(css|sass|scss)$',
     ],
-    modulePaths: jsConfig.baseUrl ? [jsConfig.baseUrl] : [],
+    modulePaths: jsConfig.additionalModulePath
+      ? [jsConfig.additionalModulePath]
+      : [],
     moduleNameMapper: {
       '^react-native$': 'react-native-web',
       '^.+\\.module\\.(css|sass|scss)$': 'identity-obj-proxy',
+      ...config.jestAliases,
     },
     moduleFileExtensions: [...paths.moduleFileExtensions, 'node'].filter(
       ext => !ext.includes('mjs')

From 637e404b7cc021556b372d64347f5c45c2282424 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 10:12:00 +0100
Subject: [PATCH 23/34] Rename config to modules

---
 packages/react-scripts/config/{config.js => modules.js}  | 4 ++--
 packages/react-scripts/config/webpack.config.js          | 7 +++----
 packages/react-scripts/scripts/utils/createJestConfig.js | 6 +++---
 3 files changed, 8 insertions(+), 9 deletions(-)
 rename packages/react-scripts/config/{config.js => modules.js} (98%)

diff --git a/packages/react-scripts/config/config.js b/packages/react-scripts/config/modules.js
similarity index 98%
rename from packages/react-scripts/config/config.js
rename to packages/react-scripts/config/modules.js
index f16f69643f7..44baf1dd633 100644
--- a/packages/react-scripts/config/config.js
+++ b/packages/react-scripts/config/modules.js
@@ -102,7 +102,7 @@ function getJestAliases(aliases) {
   }, {});
 }
 
-function getConfig() {
+function getModules() {
   // Check if TypeScript is setup
   const useTypeScript = fs.existsSync(paths.appTsConfig);
   const hasJsConfig = fs.existsSync(paths.appJsConfig);
@@ -141,4 +141,4 @@ function getConfig() {
   };
 }
 
-module.exports = getConfig();
+module.exports = getModules();
diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index 219bd5ce537..21cc50e61d5 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -30,8 +30,7 @@ const paths = require('./paths');
 const getClientEnvironment = require('./env');
 const ModuleNotFoundPlugin = require('react-dev-utils/ModuleNotFoundPlugin');
 const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin-alt');
-const config = require('./config');
-console.log(JSON.stringify(config));
+const modules = require('./modules');
 const typescriptFormatter = require('react-dev-utils/typescriptFormatter');
 // @remove-on-eject-begin
 const getCacheIdentifier = require('react-dev-utils/getCacheIdentifier');
@@ -261,7 +260,7 @@ module.exports = function(webpackEnv) {
       // if there are any conflicts. This matches Node resolution mechanism.
       // https://github.com/facebook/create-react-app/issues/253
       modules: ['node_modules'].concat(
-        config.additionalModulePath ? [config.additionalModulePath] : []
+        modules.additionalModulePath ? [modules.additionalModulePath] : []
       ),
       // These are the reasonable defaults supported by the Node ecosystem.
       // We also include JSX as a common component filename extension to support
@@ -276,7 +275,7 @@ module.exports = function(webpackEnv) {
         // 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',
-        ...config.aliases,
+        ...modules.aliases,
       },
       plugins: [
         // Adds support for installing with Plug'n'Play, leading to faster installs and adding
diff --git a/packages/react-scripts/scripts/utils/createJestConfig.js b/packages/react-scripts/scripts/utils/createJestConfig.js
index 28c5cbf0a03..272d22fb74d 100644
--- a/packages/react-scripts/scripts/utils/createJestConfig.js
+++ b/packages/react-scripts/scripts/utils/createJestConfig.js
@@ -10,7 +10,7 @@
 const fs = require('fs');
 const chalk = require('chalk');
 const paths = require('../../config/paths');
-const jsConfig = require('../../config/config');
+const modules = require('../../config/modules');
 
 module.exports = (resolve, rootDir, isEjecting) => {
   // Use this instead of `paths.testsSetup` to avoid putting
@@ -58,13 +58,13 @@ module.exports = (resolve, rootDir, isEjecting) => {
       '[/\\\\]node_modules[/\\\\].+\\.(js|jsx|ts|tsx)$',
       '^.+\\.module\\.(css|sass|scss)$',
     ],
-    modulePaths: jsConfig.additionalModulePath
+    modulePaths: modules.additionalModulePath
       ? [jsConfig.additionalModulePath]
       : [],
     moduleNameMapper: {
       '^react-native$': 'react-native-web',
       '^.+\\.module\\.(css|sass|scss)$': 'identity-obj-proxy',
-      ...config.jestAliases,
+      ...modules.jestAliases,
     },
     moduleFileExtensions: [...paths.moduleFileExtensions, 'node'].filter(
       ext => !ext.includes('mjs')

From 830415a6425bec9a3e99e4fd153fb553dab255c3 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 10:35:44 +0100
Subject: [PATCH 24/34] Fix old reference

---
 packages/react-scripts/scripts/utils/createJestConfig.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/react-scripts/scripts/utils/createJestConfig.js b/packages/react-scripts/scripts/utils/createJestConfig.js
index 272d22fb74d..cf4e86495cd 100644
--- a/packages/react-scripts/scripts/utils/createJestConfig.js
+++ b/packages/react-scripts/scripts/utils/createJestConfig.js
@@ -59,7 +59,7 @@ module.exports = (resolve, rootDir, isEjecting) => {
       '^.+\\.module\\.(css|sass|scss)$',
     ],
     modulePaths: modules.additionalModulePath
-      ? [jsConfig.additionalModulePath]
+      ? [modules.additionalModulePath]
       : [],
     moduleNameMapper: {
       '^react-native$': 'react-native-web',

From 09d98456bff6c01196fac48ff84ef5c8aa2c0976 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 10:57:58 +0100
Subject: [PATCH 25/34] Update baseUrl in Typescript compiler options

---
 packages/react-scripts/config/webpack.config.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index 21cc50e61d5..6b42e17906f 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -630,7 +630,7 @@ module.exports = function(webpackEnv) {
             isolatedModules: true,
             noEmit: true,
             jsx: 'preserve',
-            baseUrl: config.baseUrl,
+            baseUrl: modules.baseUrl,
           },
           reportFiles: [
             '**',

From db01cb99a778ea2cf78b5d5ff04ae43c3d7e22ca Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 11:22:49 +0100
Subject: [PATCH 26/34] Log modules to debug

---
 packages/react-scripts/config/webpack.config.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index 6b42e17906f..0619442907b 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -31,6 +31,7 @@ const getClientEnvironment = require('./env');
 const ModuleNotFoundPlugin = require('react-dev-utils/ModuleNotFoundPlugin');
 const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin-alt');
 const modules = require('./modules');
+console.log(modules);
 const typescriptFormatter = require('react-dev-utils/typescriptFormatter');
 // @remove-on-eject-begin
 const getCacheIdentifier = require('react-dev-utils/getCacheIdentifier');

From 47b7099a1c8d6f3cb9691381a71fb20d1ea07f74 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 11:48:16 +0100
Subject: [PATCH 27/34] Correctly return prev in reducer

---
 packages/react-scripts/config/modules.js | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/packages/react-scripts/config/modules.js b/packages/react-scripts/config/modules.js
index 44baf1dd633..17566aa40d9 100644
--- a/packages/react-scripts/config/modules.js
+++ b/packages/react-scripts/config/modules.js
@@ -99,6 +99,7 @@ function getJestAliases(aliases) {
     const match = alias + '(.*)$';
     const target = '<rootDir>/' + relativeAliasPath + '/$1';
     prev[match] = target;
+    return prev;
   }, {});
 }
 
@@ -134,9 +135,9 @@ function getModules() {
   const additionalModulePath = getAdditionalModulePath(options);
 
   return {
-    aliases,
-    jestAliases,
-    additionalModulePath,
+    aliases: aliases,
+    jestAliases: jestAliases,
+    additionalModulePath: additionalModulePath,
     useTypeScript,
   };
 }

From 50e9c6043a15670afda236320dff528ce3351565 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 12:57:51 +0100
Subject: [PATCH 28/34] Suffix alias with a forward slash to prevent conflicts
 with node_modules vendors

---
 packages/react-scripts/config/modules.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/react-scripts/config/modules.js b/packages/react-scripts/config/modules.js
index 17566aa40d9..f4277ee3edb 100644
--- a/packages/react-scripts/config/modules.js
+++ b/packages/react-scripts/config/modules.js
@@ -96,7 +96,7 @@ function getJestAliases(aliases) {
   return Object.keys(aliases).reduce(function(prev, alias) {
     const aliasPath = aliases[alias];
     const relativeAliasPath = path.relative(paths.appPath, aliasPath);
-    const match = alias + '(.*)$';
+    const match = alias + '/(.*)$';
     const target = '<rootDir>/' + relativeAliasPath + '/$1';
     prev[match] = target;
     return prev;

From 229457abe0a4dac062a26ebaecb5b00843df75a9 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 13:40:10 +0100
Subject: [PATCH 29/34] Remove console.log

---
 packages/react-scripts/config/webpack.config.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index 0619442907b..6b42e17906f 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -31,7 +31,6 @@ const getClientEnvironment = require('./env');
 const ModuleNotFoundPlugin = require('react-dev-utils/ModuleNotFoundPlugin');
 const ForkTsCheckerWebpackPlugin = require('fork-ts-checker-webpack-plugin-alt');
 const modules = require('./modules');
-console.log(modules);
 const typescriptFormatter = require('react-dev-utils/typescriptFormatter');
 // @remove-on-eject-begin
 const getCacheIdentifier = require('react-dev-utils/getCacheIdentifier');

From 216eaff0cf34af85214692c793d3439a7695b822 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 14:55:32 +0100
Subject: [PATCH 30/34] Attempt to test baseUrl for Typescript

---
 test/fixtures/typescript/src/App.test.ts     | 10 ++++++++++
 test/fixtures/typescript/src/App.ts          |  3 +++
 test/fixtures/typescript/src/absoluteLoad.ts | 13 +++++++++++++
 test/fixtures/typescript/tsconfig.json       |  4 ++++
 4 files changed, 30 insertions(+)
 create mode 100644 test/fixtures/typescript/src/absoluteLoad.ts

diff --git a/test/fixtures/typescript/src/App.test.ts b/test/fixtures/typescript/src/App.test.ts
index f02c462b553..636c014031b 100644
--- a/test/fixtures/typescript/src/App.test.ts
+++ b/test/fixtures/typescript/src/App.test.ts
@@ -13,3 +13,13 @@ it('supports decorators', () => {
   const app = new App();
   expect(app.decorated).toBe(42);
 });
+
+it('supports loading modules with baseUrl', () => {
+  const app = new App();
+  expect(app.users).toEqual([
+    { id: 1, name: '1' },
+    { id: 2, name: '2' },
+    { id: 3, name: '3' },
+    { id: 4, name: '4' },
+  ]);
+});
diff --git a/test/fixtures/typescript/src/App.ts b/test/fixtures/typescript/src/App.ts
index d803c92d199..f7c9f63f225 100644
--- a/test/fixtures/typescript/src/App.ts
+++ b/test/fixtures/typescript/src/App.ts
@@ -1,3 +1,5 @@
+import absoluteLoad from 'absoluteLoad';
+
 interface MyType {
   foo: number;
   bar: boolean;
@@ -12,6 +14,7 @@ class App {
   n = App.foo.baz!.n;
   @propertyDecorator
   decorated = 5;
+  users = absoluteLoad;
 }
 
 function annotation(target: any) {
diff --git a/test/fixtures/typescript/src/absoluteLoad.ts b/test/fixtures/typescript/src/absoluteLoad.ts
new file mode 100644
index 00000000000..5c4f7842e28
--- /dev/null
+++ b/test/fixtures/typescript/src/absoluteLoad.ts
@@ -0,0 +1,13 @@
+/**
+ * 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.
+ */
+
+export default () => [
+  { id: 1, name: '1' },
+  { id: 2, name: '2' },
+  { id: 3, name: '3' },
+  { id: 4, name: '4' },
+];
diff --git a/test/fixtures/typescript/tsconfig.json b/test/fixtures/typescript/tsconfig.json
index 504cd646e14..3c894ccf627 100644
--- a/test/fixtures/typescript/tsconfig.json
+++ b/test/fixtures/typescript/tsconfig.json
@@ -1,5 +1,9 @@
 {
   "compilerOptions": {
+    "baseUrl": "src",
+    "paths": {
+      "@": ["src"]
+    },
     "experimentalDecorators": true
   }
 }

From 26d6bdb745f0575b36ac1e51afd6d6312e559bd3 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 15:45:55 +0100
Subject: [PATCH 31/34] Add test to verify aliases work in TypeScript as well

---
 test/fixtures/typescript/src/App.test.ts | 10 ++++++++++
 test/fixtures/typescript/src/App.ts      |  4 +++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/test/fixtures/typescript/src/App.test.ts b/test/fixtures/typescript/src/App.test.ts
index 636c014031b..41958542474 100644
--- a/test/fixtures/typescript/src/App.test.ts
+++ b/test/fixtures/typescript/src/App.test.ts
@@ -23,3 +23,13 @@ it('supports loading modules with baseUrl', () => {
     { id: 4, name: '4' },
   ]);
 });
+
+it('supports loading modules with alias', () => {
+  const app = new App();
+  expect(app.usersWithAlias).toEqual([
+    { id: 1, name: '1' },
+    { id: 2, name: '2' },
+    { id: 3, name: '3' },
+    { id: 4, name: '4' },
+  ]);
+});
diff --git a/test/fixtures/typescript/src/App.ts b/test/fixtures/typescript/src/App.ts
index f7c9f63f225..f04166f9453 100644
--- a/test/fixtures/typescript/src/App.ts
+++ b/test/fixtures/typescript/src/App.ts
@@ -1,4 +1,5 @@
 import absoluteLoad from 'absoluteLoad';
+import absoluteLoadWithAlias from '@/absoluteLoad';
 
 interface MyType {
   foo: number;
@@ -14,7 +15,8 @@ class App {
   n = App.foo.baz!.n;
   @propertyDecorator
   decorated = 5;
-  users = absoluteLoad;
+  users = absoluteLoad();
+  usersWithAlias = absoluteLoadWithAlias();
 }
 
 function annotation(target: any) {

From 74ad80aaddafdea9327759bd15a29fb1ddbb2a90 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 16:52:39 +0100
Subject: [PATCH 32/34] Remove baseUrl overwrite

---
 packages/react-scripts/config/webpack.config.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index 6b42e17906f..3ec62626f0a 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -630,7 +630,6 @@ module.exports = function(webpackEnv) {
             isolatedModules: true,
             noEmit: true,
             jsx: 'preserve',
-            baseUrl: modules.baseUrl,
           },
           reportFiles: [
             '**',

From 116c9c8ba66372e3eb2db964cf17b38dc3908905 Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Mon, 7 Jan 2019 17:11:38 +0100
Subject: [PATCH 33/34] Allow setting the path of an alias to a subfolder of
 src

---
 packages/react-scripts/config/modules.js | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/packages/react-scripts/config/modules.js b/packages/react-scripts/config/modules.js
index f4277ee3edb..ef25e3e8bf0 100644
--- a/packages/react-scripts/config/modules.js
+++ b/packages/react-scripts/config/modules.js
@@ -69,7 +69,7 @@ function getAliases(options = {}) {
     if (!Array.isArray(value) || value.length > 1) {
       throw new Error(
         chalk.red.bold(
-          "Your project's `alias` can only be set to an array containing `src`." +
+          "Your project's `alias` can only be set to an array containing `src` or a subfolder of `src`." +
             ' Create React App does not support other values at this time.'
         )
       );
@@ -78,10 +78,15 @@ function getAliases(options = {}) {
     const aliasPath = value[0];
     const resolvedAliasPath = path.resolve(paths.appPath, aliasPath);
 
-    if (path.relative(paths.appSrc, resolvedAliasPath) !== '') {
+    const relativePath = path.relative(paths.appSrc, resolvedAliasPath);
+    const isSrc = relativePath === '';
+    const isSubfolderOfSrc =
+      !relativePath.startsWith('../') && !relativePath.startsWith('..\\');
+
+    if (!isSrc && !isSubfolderOfSrc) {
       throw new Error(
         chalk.red.bold(
-          "Your project's `alias` can only be set to ['src']." +
+          "Your project's `alias` can only be set to ['src'] or a subfolder of `src`." +
             ' Create React App does not support other values at this time.'
         )
       );

From ccc6b894740c764274c4dd273d215e72a23fafcb Mon Sep 17 00:00:00 2001
From: Robert van Steen <hello@rovansteen.nl>
Date: Wed, 9 Jan 2019 23:13:29 +0100
Subject: [PATCH 34/34] Work on matching jsconfig path behavior with
 webpack/jest

---
 packages/react-scripts/config/modules.js      | 43 ++++++++++++++++---
 .../react-scripts/config/webpack.config.js    |  2 +-
 .../fixtures/kitchensink/jsconfig.json        |  2 +-
 test/fixtures/typescript/tsconfig.json        |  2 +-
 4 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/packages/react-scripts/config/modules.js b/packages/react-scripts/config/modules.js
index ef25e3e8bf0..b9147cb2855 100644
--- a/packages/react-scripts/config/modules.js
+++ b/packages/react-scripts/config/modules.js
@@ -76,8 +76,15 @@ function getAliases(options = {}) {
     }
 
     const aliasPath = value[0];
-    const resolvedAliasPath = path.resolve(paths.appPath, aliasPath);
 
+    // Alias paths are relative to the baseurl.
+    // If there is no baseUrl set, it will default to the root of the app.
+    const baseUrl = options.baseUrl
+      ? path.resolve(paths.appPath, options.baseUrl)
+      : paths.appPath;
+    const resolvedAliasPath = path.resolve(baseUrl, aliasPath);
+
+    // We then check if the resolved alias path is src or a sub folder of src.
     const relativePath = path.relative(paths.appSrc, resolvedAliasPath);
     const isSrc = relativePath === '';
     const isSubfolderOfSrc =
@@ -97,13 +104,37 @@ function getAliases(options = {}) {
   }, {});
 }
 
+function getWebpackAliases(aliases) {
+  return Object.keys(aliases).reduce(function(prev, alias) {
+    let aliasPath = aliases[alias];
+    const endsWithWilcard = alias.endsWith('*');
+    // Remove trailing wildcards (/*)
+    alias = alias.replace(/\/?\*$/, '');
+    aliasPath = aliasPath.replace(/\/\*$/, '');
+    // Webpack aliases work a little bit different than jsconfig/tsconfig.json paths
+    // By default webpack aliases act as a wildcard and for an exact match you have
+    // to suffix it with a dollar sign.
+    // tsconfig/jsconfig.json work the other way around and are an exact match unless
+    // suffixed by a wildcard.
+    const webpackAlias = endsWithWilcard ? alias : alias + '$';
+    prev[webpackAlias] = aliasPath;
+    return prev;
+  }, {});
+}
+
 function getJestAliases(aliases) {
   return Object.keys(aliases).reduce(function(prev, alias) {
-    const aliasPath = aliases[alias];
+    const endsWithWilcard = alias.endsWith('*');
+    let aliasPath = aliases[alias];
+
+    alias = alias.replace(/\/?\*$/, '');
+    const match = endsWithWilcard ? alias + '(.*)$' : alias;
+
+    aliasPath = aliasPath.replace(/\*$/, '');
     const relativeAliasPath = path.relative(paths.appPath, aliasPath);
-    const match = alias + '/(.*)$';
-    const target = '<rootDir>/' + relativeAliasPath + '/$1';
-    prev[match] = target;
+    const target = '<rootDir>/' + relativeAliasPath;
+
+    prev[match] = target + (endsWithWilcard ? '/$1' : '');
     return prev;
   }, {});
 }
@@ -137,11 +168,13 @@ function getModules() {
 
   const aliases = getAliases(options);
   const jestAliases = getJestAliases(aliases);
+  const webpackAliases = getWebpackAliases(aliases);
   const additionalModulePath = getAdditionalModulePath(options);
 
   return {
     aliases: aliases,
     jestAliases: jestAliases,
+    webpackAliases: webpackAliases,
     additionalModulePath: additionalModulePath,
     useTypeScript,
   };
diff --git a/packages/react-scripts/config/webpack.config.js b/packages/react-scripts/config/webpack.config.js
index 3ec62626f0a..2c02bbffcf0 100644
--- a/packages/react-scripts/config/webpack.config.js
+++ b/packages/react-scripts/config/webpack.config.js
@@ -275,7 +275,7 @@ module.exports = function(webpackEnv) {
         // 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',
-        ...modules.aliases,
+        ...modules.webpackAliases,
       },
       plugins: [
         // Adds support for installing with Plug'n'Play, leading to faster installs and adding
diff --git a/packages/react-scripts/fixtures/kitchensink/jsconfig.json b/packages/react-scripts/fixtures/kitchensink/jsconfig.json
index f0d9b148297..344028e7fc7 100644
--- a/packages/react-scripts/fixtures/kitchensink/jsconfig.json
+++ b/packages/react-scripts/fixtures/kitchensink/jsconfig.json
@@ -2,7 +2,7 @@
   "compilerOptions": {
     "baseUrl": "src",
     "paths": {
-      "@": ["src"]
+      "@*": ["*"]
     }
   }
 }
diff --git a/test/fixtures/typescript/tsconfig.json b/test/fixtures/typescript/tsconfig.json
index 3c894ccf627..7ce41dc24cb 100644
--- a/test/fixtures/typescript/tsconfig.json
+++ b/test/fixtures/typescript/tsconfig.json
@@ -2,7 +2,7 @@
   "compilerOptions": {
     "baseUrl": "src",
     "paths": {
-      "@": ["src"]
+      "@*": ["*"]
     },
     "experimentalDecorators": true
   }