Add new useTracking react hook

README.md

@@ -111,6 +111,24 @@ export default track({
 })(FooPage);
 ```
 
+### Usage with React Hooks
+
+Following the example above, once a component is wrapped with `track` we can access a `tracking` object via the `useTracking` hook from anywhere in the sub-tree:
+
+```js
+import { useTracking } from 'react-tracking'
+
+const SomeChild = props => {
+  const tracking = useTracking()
+
+  <div
+    onClick={() => {
+      tracking.trackEvent({ action: 'click' });
+    }}
+  />
+}
+```
+
 This is also how you would use this module without `@decorators`, although this is obviously awkward and the decorator syntax is recommended.
 
 ### Custom `options.dispatch()` for tracking data

package.json

@@ -54,7 +54,7 @@
   },
   "peerDependencies": {
     "core-js": "2.x",
-    "react": "^16.3",
+    "react": "^16.8",
     "prop-types": "^15.x"
   },
   "devDependencies": {

src/__tests__/e2e.test.js

@@ -1,5 +1,5 @@
 /* eslint-disable react/destructuring-assignment,react/no-multi-comp,react/prop-types,react/prefer-stateless-function  */
-import React from 'react';
+import React, { useContext } from 'react';
 import { mount } from 'enzyme';
 
 const dispatchTrackingEvent = jest.fn();
@@ -12,13 +12,13 @@ const testState = { booleanState: true };
 
 describe('e2e', () => {
   // eslint-disable-next-line global-require
-  const track = require('../').default;
+  const { default: track, useTracking, ReactTrackingContext } = require('../');
 
   beforeEach(() => {
     jest.clearAllMocks();
   });
 
-  it('defaults moslty everything', () => {
+  it('defaults mostly everything', () => {
     @track(null, { process: () => null })
     class TestDefaults extends React.Component {
       render() {
@@ -584,4 +584,60 @@ describe('e2e', () => {
       page: 'Page',
     });
   });
+
+  it('root context items are accessible to children', () => {
+    const App = track()(() => {
+      return <Child />;
+    });
+
+    const Child = () => {
+      const trackingContext = useContext(ReactTrackingContext);
+      expect(Object.keys(trackingContext.tracking)).toEqual([
+        'data',
+        'dispatch',
+        'process',
+      ]);
+      return <div />;
+    };
+
+    mount(<App />);
+  });
+
+  it('dispatches tracking events from a useTracking hook tracking object', () => {
+    const outerTrackingData = {
+      page: 'Page',
+    };
+
+    const Page = track(outerTrackingData, { dispatch })(props => {
+      return props.children;
+    });
+
+    const Child = () => {
+      const tracking = useTracking();
+
+      expect(tracking.getTrackingData()).toEqual(outerTrackingData);
+
+      return (
+        <button
+          type="button"
+          onClick={() => {
+            tracking.trackEvent({ event: 'buttonClick' });
+          }}
+        />
+      );
+    };
+
+    const wrappedApp = mount(
+      <Page>
+        <Child />
+      </Page>
+    );
+
+    wrappedApp.find('button').simulate('click');
+
+    expect(dispatch).toHaveBeenCalledWith({
+      ...outerTrackingData,
+      event: 'buttonClick',
+    });
+  });
 });

src/__tests__/useTracking.test.js

@@ -0,0 +1,55 @@
+import { mount } from 'enzyme';
+import React from 'react';
+import { renderToString } from 'react-dom/server';
+import track from '../withTrackingComponentDecorator';
+import useTracking from '../useTracking';
+
+describe('useTracking', () => {
+  it('throws error if tracking context not present', () => {
+    const ThrowMissingContext = () => {
+      useTracking();
+      return <div>hi</div>;
+    };
+    try {
+      renderToString(<ThrowMissingContext />);
+    } catch (error) {
+      expect(error.message).toContain(
+        'Attempting to call `useTracking` without a ReactTrackingContext present'
+      );
+    }
+  });
+
+  it('dispatches tracking events from a useTracking hook tracking object', () => {
+    const outerTrackingData = {
+      page: 'Page',
+    };
+
+    const dispatch = jest.fn();
+
+    const App = track(outerTrackingData, { dispatch })(() => {
+      const tracking = useTracking();
+
+      expect(tracking.getTrackingData()).toEqual({
+        page: 'Page',
+      });
+
+      return (
+        <button
+          type="button"
+          onClick={() =>
+            tracking.trackEvent({
+              event: 'buttonClick',
+            })
+          }
+        />
+      );
+    });
+
+    const wrapper = mount(<App />);
+    wrapper.simulate('click');
+    expect(dispatch).toHaveBeenCalledWith({
+      ...outerTrackingData,
+      event: 'buttonClick',
+    });
+  });
+});

src/index.js

@@ -5,4 +5,5 @@ export {
 } from './withTrackingComponentDecorator';
 export { default as trackEvent } from './trackEventMethodDecorator';
 export { default as TrackingPropType } from './TrackingPropType';
+export { default as useTracking } from './useTracking';
 export { default } from './trackingHoC';

src/useTracking.js

@@ -0,0 +1,29 @@
+import merge from 'deepmerge';
+import { useContext, useCallback } from 'react';
+import { ReactTrackingContext } from './withTrackingComponentDecorator';
+
+export default function useTracking() {
+  const trackingContext = useContext(ReactTrackingContext);
+
+  if (!(trackingContext && trackingContext.tracking)) {
+    throw new Error(
+      'Attempting to call `useTracking` ' +
+        'without a ReactTrackingContext present. Did you forget to wrap the top of ' +
+        'your component tree with `track`?'
+    );
+  }
+
+  const trackEvent = useCallback(
+    data => {
+      return trackingContext.tracking.dispatch(
+        merge(trackingContext.tracking.data, data)
+      );
+    },
+    [trackingContext.tracking.data]
+  );
+
+  return {
+    getTrackingData: () => trackingContext.tracking.data,
+    trackEvent,
+  };
+}