Add Jest typeahead plugin (#5213)

* Add Jest typeahead plugin

* Update jest-watch-typeahead to 0.2.1

Author: gaearon

packages/react-scripts/package.json

@@ -52,6 +52,7 @@
     "jest": "23.6.0",
     "jest-pnp-resolver": "1.0.2",
     "jest-resolve": "23.6.0",
+    "jest-watch-typeahead": "^0.2.1",
     "mini-css-extract-plugin": "0.4.3",
     "optimize-css-assets-webpack-plugin": "5.0.1",
     "pnp-webpack-plugin": "1.2.1",

packages/react-scripts/scripts/utils/createJestConfig.js

@@ -64,6 +64,10 @@ module.exports = (resolve, rootDir, isEjecting) => {
     moduleFileExtensions: [...paths.moduleFileExtensions, 'node'].filter(
       ext => !ext.includes('mjs')
     ),
+    watchPlugins: [
+      require.resolve('jest-watch-typeahead/filename'),
+      require.resolve('jest-watch-typeahead/testname'),
+    ],
   };
   if (rootDir) {
     config.rootDir = rootDir;