Replace mocha with jest

.eslintrc.js

@@ -8,14 +8,15 @@ module.exports = {
     'prettier/flowtype',
   ],
 
-  plugins: ['flowtype', 'prettier'],
+  plugins: ['flowtype', 'prettier', 'jest'],
 
   globals: {
     __DEV__: true,
   },
 
   env: {
     browser: true,
+    'jest/globals': true,
   },
 
   rules: {

package.json

@@ -31,6 +31,7 @@
     "babel-cli": "^6.16.0",
     "babel-core": "^6.17.0",
     "babel-eslint": "^7.0.0",
+    "babel-jest": "^20.0.3",
     "babel-plugin-transform-runtime": "^6.15.0",
     "babel-preset-flow": "^6.23.0",
     "babel-preset-latest": "^6.16.0",
@@ -44,21 +45,22 @@
     "eslint-config-prettier": "^2.3.0",
     "eslint-plugin-flowtype": "^2.35.0",
     "eslint-plugin-import": "^2.2.0",
+    "eslint-plugin-jest": "^20.0.3",
     "eslint-plugin-prettier": "^2.1.2",
     "flow-bin": "^0.51.0",
-    "istanbul": "^1.1.0-alpha.1",
+    "jest": "^20.0.4",
     "jest-codemods": "^0.10.2",
-    "mocha": "^3.1.2",
     "prettier": "^1.5.3",
+    "regenerator-runtime": "^0.10.5",
     "rollup": "^0.45.2",
     "rollup-plugin-babel": "^2.6.1",
     "sinon": "^2.0.0-pre.3"
   },
   "scripts": {
     "lint": "eslint src test tools",
-    "test": "mocha --compilers js:babel-register",
-    "test:watch": "mocha --compilers js:babel-register --reporter min --watch",
-    "test:cover": "babel-node ./node_modules/istanbul/lib/cli.js cover ./node_modules/mocha/bin/_mocha",
+    "test": "jest",
+    "test:watch": "jest --watch",
+    "test:cover": "jest --coverage",
     "coveralls": "cat ./coverage/lcov.info | coveralls",
     "build": "node tools/build",
     "prepublish": "npm run build",

test/GreetingSpec.js → src/__tests__/GreetingSpec.js

@@ -7,21 +7,20 @@
  * LICENSE.txt file in the root directory of this source tree.
  */
 
-import { expect } from 'chai';
-import Greeting from '../src/Greeting';
+import Greeting from '../Greeting';
 
 describe('Greeting', () => {
   describe('greeting.hello()', () => {
     it('should return welcome message for a guest user', () => {
       const greeting = new Greeting();
       const message = greeting.hello();
-      expect(message).to.be.equal('Welcome, Guest!');
+      expect(message).toBe('Welcome, Guest!');
     });
 
     it('should return welcome message for a named user', () => {
       const greeting = new Greeting('John');
       const message = greeting.hello();
-      expect(message).to.be.equal('Welcome, John!');
+      expect(message).toBe('Welcome, John!');
     });
   });
 });