#24 configure jest and enzyme

__mocks__/fileMock.js

@@ -0,0 +1 @@
+module.exports = 'test-file-stub'

__mocks__/styleMock.js

@@ -0,0 +1 @@
+module.exports = {}

package.json

@@ -17,16 +17,20 @@
   "scripts": {
     "build": "webpack --config webpack.js --mode=production",
     "start": "webpack-dev-server --hot --open --config webpack.js --mode=development",
-    "lint": "eslint src/"
+    "lint": "eslint src/",
+    "test": "jest --watch"
   },
   "devDependencies": {
     "@babel/core": "^7.12.9",
     "@babel/plugin-proposal-class-properties": "^7.8.3",
     "@babel/preset-env": "^7.12.7",
     "@babel/preset-react": "^7.12.7",
+    "babel-jest": "^26.6.3",
     "babel-loader": "^8.2.2",
     "clean-webpack-plugin": "^3.0.0",
     "css-loader": "^5.0.1",
+    "enzyme": "^3.11.0",
+    "enzyme-adapter-react-16": "^1.15.5",
     "eslint": "^6.8.0",
     "eslint-config-react-app": "^5.2.1",
     "eslint-config-standard": "^14.1.1",
@@ -41,6 +45,8 @@
     "file-loader": "^6.2.0",
     "html-loader": "^1.3.2",
     "html-webpack-plugin": "^4.5.0",
+    "jest": "^26.6.3",
+    "jest-enzyme": "^7.1.2",
     "mini-css-extract-plugin": "^1.3.1",
     "node-sass": "^5.0.0",
     "optimize-css-assets-webpack-plugin": "^5.0.4",
@@ -50,5 +56,11 @@
     "webpack": "^4.44.2",
     "webpack-cli": "^4.2.0",
     "webpack-dev-server": "^3.10.3"
+  },
+  "jest": {
+    "moduleNameMapper": {
+      "\\.(css|less|sass|scss)$": "<rootDir>/__mocks__/styleMock.js",
+      "\\.(gif|png|ttf|eot|svg)$": "<rootDir>/__mocks__/fileMock.js"
+    }
   }
-}
+}

src/components/app/app.test.js

@@ -0,0 +1,12 @@
+import React from 'react'
+import Enzyme, { shallow } from 'enzyme'
+import EnzymeAdapter from 'enzyme-adapter-react-16'
+
+import App from './app'
+
+Enzyme.configure({ adapter: new EnzymeAdapter() })
+
+test('renders without error', () => {
+  const wrapper = shallow(<App />)
+  expect(wrapper).toBeTruthy()
+})