Mocha unexpected identifier

Question

I want to set up a testing environnement for my react app using Mocha+chai+enzyme , the problem is that , many things are missing and i don't know how to fix that since i am a beginner when it comes to use babel or webpack ... etc

So first of all , i have a project that i created with create-react-app i installed all the libraries with npm we already have a default app.test.js file , so i just changed the code

My package.json:

{
  "name": "****",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@babel/core": "7.1.0",
    "@svgr/webpack": "2.4.1",
    "@types/react": "^16.7.20",
    "@types/react-dom": "^16.0.11",
    "apollo-boost": "^0.1.23",
    "babel-core": "7.0.0-bridge.0",
    "babel-eslint": "9.0.0",
    "babel-jest": "23.6.0",
    "babel-loader": "8.0.4",
    "babel-plugin-named-asset-import": "^0.2.3",
    "babel-preset-react-app": "^6.1.0",
    "bfj": "6.1.1",
    "case-sensitive-paths-webpack-plugin": "2.1.2",
    "chalk": "2.4.1",
    "css-loader": "1.0.0",
    "dotenv": "6.0.0",
    "dotenv-expand": "4.2.0",
    "eslint": "5.6.0",
    "eslint-config-react-app": "^3.0.5",
    "eslint-loader": "2.1.1",
    "eslint-plugin-flowtype": "2.50.1",
    "eslint-plugin-import": "2.14.0",
    "eslint-plugin-jsx-a11y": "6.1.2",
    "eslint-plugin-react": "7.11.1",
    "file-loader": "2.0.0",
    "fork-ts-checker-webpack-plugin-alt": "0.4.14",
    "fs-extra": "7.0.0",
    "graphql": "^14.0.2",
    "graphql-tag": "^2.10.0",
    "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": "1.1.0",
    "postcss-flexbugs-fixes": "4.1.0",
    "postcss-loader": "3.0.0",
    "postcss-preset-env": "6.0.6",
    "postcss-safe-parser": "4.0.1",
    "react": "^16.7.0",
    "react-apollo": "^2.3.3",
    "react-app-polyfill": "^0.1.3",
    "react-dev-utils": "^6.1.1",
    "react-dom": "^16.7.0",
    "resolve": "1.8.1",
    "sass-loader": "7.1.0",
    "style-loader": "0.23.0",
    "terser-webpack-plugin": "1.1.0",
    "url-loader": "1.1.1",
    "webpack": "4.19.1",
    "webpack-dev-server": "^3.1.14",
    "webpack-manifest-plugin": "2.0.4",
    "workbox-webpack-plugin": "3.6.3"
  },
  "scripts": {
    "start": "node scripts/start.js",
    "build": "node scripts/build.js",
    "test": "mocha src/App.test.js"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": [
    ">0.2%",
    "not dead",
    "not ie <= 11",
    "not op_mini all"
  ],
  "jest": {
    "collectCoverageFrom": [
      "src/**/*.{js,jsx,ts,tsx}",
      "!src/**/*.d.ts"
    ],
    "resolver": "jest-pnp-resolver",
    "setupFiles": [
      "react-app-polyfill/jsdom"
    ],
    "testMatch": [
      "<rootDir>/src/**/__tests__/**/*.{js,jsx,ts,tsx}",
      "<rootDir>/src/**/?(*.)(spec|test).{js,jsx,ts,tsx}"
    ],
    "testEnvironment": "jsdom",
    "testURL": "http://localhost",
    "transform": {
      "^.+\\.(js|jsx|ts|tsx)$": "<rootDir>/node_modules/babel-jest",
      "^.+\\.css$": "<rootDir>/config/jest/cssTransform.js",
      "^(?!.*\\.(js|jsx|ts|tsx|css|json)$)": "<rootDir>/config/jest/fileTransform.js"
    },
    "transformIgnorePatterns": [
      "[/\\\\]node_modules[/\\\\].+\\.(js|jsx|ts|tsx)$",
      "^.+\\.module\\.(css|sass|scss)$"
    ],
    "moduleNameMapper": {
      "^react-native$": "react-native-web",
      "^.+\\.module\\.(css|sass|scss)$": "identity-obj-proxy"
    },
    "moduleFileExtensions": [
      "web.js",
      "js",
      "web.ts",
      "ts",
      "web.tsx",
      "tsx",
      "json",
      "web.jsx",
      "jsx",
      "node"
    ]
  },
  "babel": {
    "presets": [
      "react-app"
    ]
  },
  "devDependencies": {
    "@babel/preset-env": "^7.3.1",
    "@babel/preset-react": "^7.0.0",
    "@babel/preset-stage-0": "^7.0.0",
    "awesome-typescript-loader": "^5.2.1",
    "babel-preset-env": "^1.7.0",
    "chai": "^4.2.0",
    "enzyme": "^3.8.0",
    "enzyme-adapter-react-16": "^1.9.1",
    "jsdom": "^13.2.0",
    "mocha": "^5.2.0",
    "react-addons-test-utils": "^15.6.2",
    "source-map-loader": "^0.2.4",
    "typescript": "^3.2.2"
  }
}

My App.test.js

import React from 'react';
import { configure , shallow } from 'enzyme'
import { expect } from 'chai'

import Adapter from 'enzyme-adapter-react-16'
configure({ adapter: new Adapter() });

import App from './App';

describe('App', function() {
    it('should work', function() {
        const wrapper = shallow(<App />)
        expect('1').to.equal('1');
    })
});

And my .babelrc : some people told me to install these presets but same problem

{
    "presets": ["@babel/preset-react", "@babel/preset-env"]
}

when i run npm test : i have this :

C:\Users\kino96\Desktop\JavaScript\OurFirstProject\src\App.test.js:1 (function (exports, require, module, __filename, __dirname) { import React from 'react';

SyntaxError: Unexpected identifier at new Script (vm.js:79:7) at createScript (vm.js:251:10) ...

Answer 1

You need to tell Mocha that it should use Babel for your test files. The documentation (here) seems to be out of date, but this should work:

"devDependencies": {
  ...
  "@babel/register"
},
"scripts": {
  ...
  "test": "mocha --require @babel/register src/App.test.js"
}