Add Enzyme to www and add a test for the NextStepButton. This takes our enzyme helpers from gui and copies them here. It also requires a babel plugin to play nicely with jest.

.babelrc

@@ -1,6 +1,7 @@
 {
     "plugins": [
-        "transform-object-rest-spread"
+        "transform-object-rest-spread",
+        "transform-require-context"
     ],
     "presets": ["es2015", "react"],
 }

package.json

@@ -61,6 +61,7 @@
     "babel-eslint": "10.0.2",
     "babel-loader": "7.1.0",
     "babel-plugin-transform-object-rest-spread": "6.26.0",
+    "babel-plugin-transform-require-context": "^0.1.1",
     "babel-preset-es2015": "6.22.0",
     "babel-preset-react": "6.22.0",
     "bowser": "1.9.4",
@@ -71,6 +72,8 @@
     "copy-webpack-plugin": "0.2.0",
     "create-react-class": "15.6.2",
     "css-loader": "0.23.1",
+    "enzyme": "3.10.0",
+    "enzyme-adapter-react-16": "1.14.0",
     "eslint": "5.16.0",
     "eslint-config-scratch": "5.0.0",
     "eslint-plugin-cypress": "^2.0.1",
@@ -133,6 +136,16 @@
     "webpack-dev-middleware": "2.0.4",
     "xhr": "2.2.0"
   },
+  "jest": {
+    "setupFiles": [
+      "<rootDir>/test/helpers/enzyme-setup.js"
+  ],
+
+      "moduleNameMapper": {
+        "\\.(jpg|jpeg|png|gif|eot|otf|webp|svg|ttf|woff|woff2|mp4|webm|wav|mp3|m4a|aac|oga)$": "<rootDir>/test/__mocks__/fileMock.js",
+        "\\.(css|less|scss)$": "<rootDir>/test/__mocks__/styleMock.js"
+      }
+  },
   "nyc": {
     "include": [
       "bin/**/*.js",

test/__mocks__/fileMock.js

@@ -0,0 +1,3 @@
+// __mocks__/fileMock.js
+
+module.exports = 'test-file-stub';

test/__mocks__/styleMock.js

@@ -0,0 +1,3 @@
+// __mocks__/styleMock.js
+
+module.exports = {};

test/helpers/enzyme-setup.js

@@ -0,0 +1,4 @@
+import Enzyme from 'enzyme';
+import Adapter from 'enzyme-adapter-react-16';
+
+Enzyme.configure({adapter: new Adapter()});

test/helpers/intl-helpers.jsx

@@ -0,0 +1,39 @@
+/*
+ * Helpers for using enzyme and react-test-renderer with react-intl
+ * Directly from https://github.com/yahoo/react-intl/wiki/Testing-with-React-Intl
+ */
+import React from 'react';
+import renderer from 'react-test-renderer';
+import {IntlProvider, intlShape} from 'react-intl';
+import {mount, shallow} from 'enzyme';
+
+const intlProvider = new IntlProvider({locale: 'en'}, {});
+const {intl} = intlProvider.getChildContext();
+
+const nodeWithIntlProp = node => React.cloneElement(node, {intl});
+
+const shallowWithIntl = (node, {context} = {}) => shallow(
+    nodeWithIntlProp(node),
+    {
+        context: Object.assign({}, context, {intl})
+    }
+);
+
+const mountWithIntl = (node, {context, childContextTypes} = {}) => mount(
+    nodeWithIntlProp(node),
+    {
+        context: Object.assign({}, context, {intl}),
+        childContextTypes: Object.assign({}, {intl: intlShape}, childContextTypes)
+    }
+);
+
+// react-test-renderer component for use with snapshot testing
+const componentWithIntl = (children, props = {locale: 'en'}) => renderer.create(
+    <IntlProvider {...props}>{children}</IntlProvider>
+);
+
+export {
+    componentWithIntl,
+    shallowWithIntl,
+    mountWithIntl
+};

test/unit/components/next-step-button.test.js

@@ -0,0 +1,32 @@
+import React from 'react';
+import {mountWithIntl} from '../../helpers/intl-helpers.jsx';
+import NextStepButton from '../../../src/components/join-flow/next-step-button';
+import Spinner from '../../../src/components/spinner/spinner.jsx';
+
+describe('NextStepButton', () => {
+    const defaultProps = () => ({
+        text: 'I am a button',
+        waiting: false
+
+    });
+    test('testing spinner does not show and button enabled', () => {
+        const component = mountWithIntl(
+            <NextStepButton
+                {...defaultProps()}
+            />
+        );
+        expect(component.find(Spinner).exists()).toEqual(false);
+        expect(component.find('button[type="submit"]').prop('disabled')).toBe(false);
+
+    });
+    test('testing spinner does show and button disabled', () => {
+        const component = mountWithIntl(
+            <NextStepButton
+                {...defaultProps()}
+            />
+        );
+        component.setProps({waiting: true});
+        expect(component.find(Spinner).exists()).toEqual(true);
+        expect(component.find('button[type="submit"]').prop('disabled')).toBe(true);
+    });
+});