Adds configuration for jest

Author: Maël Nison

packages/react-scripts/package.json

@@ -47,6 +47,8 @@
     "html-webpack-plugin": "4.0.0-alpha.2",
     "identity-obj-proxy": "3.0.0",
     "jest": "23.6.0",
+    "jest-pnp-resolver": "^1.0.1",
+    "jest-resolve": "23.6.0",
     "mini-css-extract-plugin": "0.4.3",
     "optimize-css-assets-webpack-plugin": "5.0.1",
     "pnp-webpack-plugin": "1.0.2",

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

@@ -22,7 +22,8 @@ module.exports = (resolve, rootDir, isEjecting) => {
   // in Jest configs. We need help from somebody with Windows to determine this.
   const config = {
     collectCoverageFrom: ['src/**/*.{js,jsx}'],
-    setupFiles: ['react-app-polyfill/jsdom'],
+    resolver: require.resolve('jest-pnp-resolver'),
+    setupFiles: [require.resolve('react-app-polyfill/jsdom')],
     setupTestFrameworkScriptFile: setupTestsFile,
     testMatch: [
       '<rootDir>/src/**/__tests__/**/*.{js,jsx}',