Upgrade to Jest 26

package.json

@@ -30,7 +30,7 @@
     "get-port": "^5.1.1",
     "globby": "^11.0.0",
     "husky": "^4.2.5",
-    "jest": "25.5.4",
+    "jest": "26.0.1",
     "lerna": "3.20.2",
     "lerna-changelog": "~0.8.2",
     "lint-staged": "^10.2.2",

packages/babel-plugin-named-asset-import/package.json

@@ -20,7 +20,7 @@
   },
   "devDependencies": {
     "babel-plugin-tester": "^8.0.1",
-    "jest": "25.5.4"
+    "jest": "26.0.1"
   },
   "scripts": {
     "test": "jest"

packages/confusing-browser-globals/package.json

@@ -20,6 +20,6 @@
     "index.js"
   ],
   "devDependencies": {
-    "jest": "25.5.4"
+    "jest": "26.0.1"
   }
 }

packages/react-dev-utils/package.json

@@ -79,7 +79,7 @@
   },
   "devDependencies": {
     "cross-env": "^7.0.2",
-    "jest": "25.5.4"
+    "jest": "26.0.1"
   },
   "scripts": {
     "test": "cross-env FORCE_COLOR=true jest"

packages/react-error-overlay/package.json

@@ -38,7 +38,7 @@
     "@babel/core": "7.10.1",
     "anser": "1.4.9",
     "babel-eslint": "10.1.0",
-    "babel-jest": "^25.2.6",
+    "babel-jest": "^26.0.1",
     "babel-loader": "8.1.0",
     "babel-preset-react-app": "^9.1.2",
     "chalk": "2.4.2",
@@ -52,7 +52,7 @@
     "eslint-plugin-react": "7.20.0",
     "flow-bin": "^0.116.0",
     "html-entities": "1.3.1",
-    "jest": "25.5.4",
+    "jest": "26.0.1",
     "jest-fetch-mock": "2.1.2",
     "object-assign": "4.1.1",
     "promise": "8.1.0",

packages/react-scripts/fixtures/kitchensink/template.json

@@ -2,7 +2,7 @@
   "package": {
     "dependencies": {
       "bootstrap": "4.3.1",
-      "jest": "25.5.4",
+      "jest": "26.0.1",
       "node-sass": "4.x",
       "normalize.css": "7.0.0",
       "prop-types": "15.7.2",

packages/react-scripts/package.json

@@ -34,7 +34,7 @@
     "@typescript-eslint/eslint-plugin": "^2.10.0",
     "@typescript-eslint/parser": "^2.10.0",
     "babel-eslint": "10.1.0",
-    "babel-jest": "^25.2.6",
+    "babel-jest": "^26.0.1",
     "babel-loader": "8.1.0",
     "babel-plugin-named-asset-import": "^0.3.6",
     "babel-preset-react-app": "^9.1.2",
@@ -56,9 +56,10 @@
     "fs-extra": "^9.0.0",
     "html-webpack-plugin": "4.3.0",
     "identity-obj-proxy": "3.0.0",
-    "jest": "25.5.4",
-    "jest-resolve": "25.5.1",
-    "jest-watch-typeahead": "0.5.0",
+    "jest": "26.0.1",
+    "jest-circus": "26.0.1",
+    "jest-resolve": "26.0.1",
+    "jest-watch-typeahead": "0.6.0",
     "mini-css-extract-plugin": "0.9.0",
     "optimize-css-assets-webpack-plugin": "5.0.3",
     "pnp-webpack-plugin": "1.6.4",

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

@@ -39,6 +39,7 @@ module.exports = (resolve, rootDir, isEjecting) => {
       '<rootDir>/src/**/*.{spec,test}.{js,jsx,ts,tsx}',
     ],
     testEnvironment: 'jsdom',
+    testRunner: require.resolve('jest-circus/runner'),
     transform: {
       '^.+\\.(js|jsx|mjs|cjs|ts|tsx)$': isEjecting
         ? '<rootDir>/node_modules/babel-jest'

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

@@ -59,9 +59,17 @@ function verifyTypeScriptSetup() {
   // Ensure typescript is installed
   let ts;
   try {
+    // TODO: Remove this hack once `globalThis` issue is resolved
+    // https://github.com/jsdom/jsdom/issues/2961
+    const globalThisWasDefined = !!global.globalThis;
+
     ts = require(resolve.sync('typescript', {
       basedir: paths.appNodeModules,
     }));
+
+    if (!globalThisWasDefined && !!global.globalThis) {
+      delete global.globalThis;
+    }
   } catch (_) {
     console.error(
       chalk.bold.red(

test/fixtures/jsconfig/src/App.js

@@ -32,7 +32,7 @@ export default class App extends Component {
   render() {
     return (
       <div>
-        {this.state.users.map((user) => (
+        {this.state.users.map(user => (
           <div key={user.id}>{user.name}</div>
         ))}
       </div>