Merge pull request #14 from Coobaha/patch-1

Fixes HMR when used as a global decorator

src/__tests__/index.tsx

@@ -56,4 +56,22 @@ describe("Background Decorator", () => {
 
     expect(spy).toBeCalled();
   });
+
+  it("should update story on change", () => {
+    const SpiedChannel = new EventEmitter();
+    const nextStory = jest.fn(() => <p>I am next story!</p>);
+    const backgroundDecorator = shallow(<BackgroundDecorator story={testStory} channel={SpiedChannel} />);
+
+    backgroundDecorator.setProps({ story: nextStory });
+    expect(nextStory).toBeCalled();
+  });
+
+  it("should not update story on other props change", () => {
+    const SpiedChannel = new EventEmitter();
+    const story = jest.fn(() => <p>I am the only one!</p>);
+    const backgroundDecorator = shallow(<BackgroundDecorator story={story} channel={SpiedChannel} />);
+
+    backgroundDecorator.setProps({ randomProp: true });
+    expect(story.mock.calls.length).toBe(1);
+  });
 });

src/index.tsx

@@ -41,6 +41,12 @@ export class BackgroundDecorator extends React.Component<any, any> {
     this.channel.emit("background-set", this.props.backgrounds);
   }
 
+  componentWillReceiveProps(nextProps) {
+    if (nextProps.story !== this.props.story) {
+      this.story = nextProps.story();
+    }
+  }
+
   componentWillUnmount() {
     this.channel.removeListener("background", this.setBackground);
     this.channel.emit("background-unset");