Merge pull request #11 from cfaloon/snapshot-tests

We have snapshots!

src/App.test.js

@@ -1,8 +1,50 @@
 import React from 'react';
 import ReactDOM from 'react-dom';
 import App from './App';
+import renderer from 'react-test-renderer';
 
 it('renders without crashing', () => {
  const div = document.createElement('div');
  ReactDOM.render(<App />, div);
 });
+
+// SNAPSHOT TESTS follow link for more details
+// https://facebook.github.io/jest/docs/en/snapshot-testing.html#snapshot-testing-with-jest
+it('enters numbers to display', () => {
+ const app = renderer.create(<App />);
+ expect(app.toJSON()).toMatchSnapshot();
+
+ app.getInstance().handleReceiveInput('4');
+ expect(app.toJSON()).toMatchSnapshot();
+
+ app.getInstance().handleReceiveInput('64');
+ expect(app.toJSON()).toMatchSnapshot();
+});
+
+it('clears screen', () => {
+ const app = renderer.create(<App />);
+ expect(app.toJSON()).toMatchSnapshot();
+
+ app.getInstance().handleReceiveInput('4');
+ expect(app.toJSON()).toMatchSnapshot();
+
+ app.getInstance().handleReceiveInput('0');
+ expect(app.toJSON()).toMatchSnapshot();
+});
+
+it('performs addition', () => {
+ const app = renderer.create(<App />);
+ expect(app.toJSON()).toMatchSnapshot();
+
+ app.getInstance().handleReceiveInput('4');
+ expect(app.toJSON()).toMatchSnapshot();
+
+ app.getInstance().handleReceiveOperator('+');
+ expect(app.toJSON()).toMatchSnapshot();
+
+ app.getInstance().handleReceiveInput('7');
+ expect(app.toJSON()).toMatchSnapshot();
+
+ app.getInstance().handleReceiveOperator('=');
+ expect(app.toJSON()).toMatchSnapshot();
+});