adds unit tests for the message component

src/components/Message/Message.test.js

@@ -1,7 +1,56 @@
+import React from 'react';
 import Message from './index';
 
+function Component(props) {
+  return (
+    <Message {...props}>
+      lorem ipsum
+    </Message>
+  );
+}
+
 describe('Message', () => {
-  it('TODO', () => {
-    expect(true).to.equal(true);
+  const infoThemeClass = 'tyk-message--info';
+  const successThemeClass = 'tyk-message--success';
+  const noMarginClass = 'no-margin';
+  const selectors = {
+    message: '.tyk-message',
+    closeIcon: '.tyk-icon.tykon-x',
+  };
+
+  it('renders the component with the info theme by default', () => {
+    cy.mount(<Component />)
+      .get(selectors.message)
+      .should('exist')
+      .and('have.class', infoThemeClass);
+  });
+
+  it('can be rendered with a different theme', () => {
+    cy.mount(<Component theme="success" />)
+      .get(selectors.message)
+      .should('have.class', successThemeClass);
+  });
+
+  it('can be rendered with no margins', () => {
+    cy.mount(<Component noMargin />)
+      .get(selectors.message)
+      .should('have.class', noMarginClass);
+  });
+
+  it('can have custom classes', () => {
+    const myClass = 'foo';
+    cy.mount(<Component className={myClass} />)
+      .get(selectors.message)
+      .should('have.class', myClass);
+  });
+
+  it('renders an icon that calls the onClose callback when clicked', () => {
+    const onClose = cy.stub();
+    cy.mount(<Component onClose={onClose} />)
+      .get(selectors.closeIcon)
+      .click()
+      .then(() => {
+        expect(onClose).to.be.called;
+      });
   });
 });