Improve badge for click tracking and links

src/components/Badge.js

@@ -1,13 +1,27 @@
 import React from 'react';
 import PropTypes from 'prop-types';
-import {omit} from 'ramda';
 import {Badge as RSBadge} from 'reactstrap';
+import Link from '../private/Link';
 
 const Badge = props => {
-  const {children, loading_state, ...otherProps} = props;
+  const {children, href, loading_state, setProps, ...otherProps} = props;
+
+  const incrementClicks = () => {
+    if (setProps) {
+      setProps({
+        n_clicks: props.n_clicks + 1,
+        n_clicks_timestamp: Date.now()
+      });
+    }
+  };
+
+  otherProps[href ? 'preOnClick' : 'onClick'] = incrementClicks;
+
   return (
     <RSBadge
-      {...omit(['setProps'], otherProps)}
+      tag={href && Link}
+      href={href}
+      {...otherProps}
       data-dash-is-loading={
         (loading_state && loading_state.is_loading) || undefined
       }
@@ -17,6 +31,11 @@ const Badge = props => {
   );
 };
 
+Badge.defaultProps = {
+  n_clicks: 0,
+  n_clicks_timestamp: -1
+};
+
 Badge.propTypes = {
   /**
    * The ID of this component, used to identify dash components
@@ -84,7 +103,30 @@ Badge.propTypes = {
      * Holds the name of the component that is loading
      */
     component_name: PropTypes.string
-  })
+  }),
+
+  /**
+   * If true, the browser will treat this as an external link,
+   * forcing a page refresh at the new location. If false,
+   * this just changes the location without triggering a page
+   * refresh. Use this if you are observing dcc.Location, for
+   * instance. Defaults to true for absolute URLs and false
+   * otherwise.
+   */
+  external_link: PropTypes.bool,
+
+  /**
+   * An integer that represents the number of times
+   * that this element has been clicked on.
+   */
+  n_clicks: PropTypes.number,
+
+  /**
+   * An integer that represents the time (in ms since 1970)
+   * at which n_clicks changed. This can be used to tell
+   * which button was changed most recently.
+   */
+  n_clicks_timestamp: PropTypes.number
 };
 
 export default Badge;

src/components/__tests__/Badge.test.js

@@ -0,0 +1,25 @@
+import React from 'react';
+import {mount, shallow} from 'enzyme';
+
+import Badge from '../Badge';
+
+describe('Badge', () => {
+  it('should track clicks', () => {
+    const mockSetProps = jest.fn();
+    const wrapper = shallow(<Badge setProps={mockSetProps}>Badge</Badge>);
+    wrapper.simulate('click');
+    expect(mockSetProps.mock.calls).toHaveLength(1);
+    expect(mockSetProps.mock.calls[0][0].n_clicks).toBe(1);
+    expect(typeof mockSetProps.mock.calls[0][0].n_clicks_timestamp).toBe(
+      'number'
+    );
+  });
+
+  it('should render as link when href is set', () => {
+    const href = '#href';
+    const wrapper = mount(<Badge href={href}>Badge</Badge>);
+    const linkComponent = wrapper.find('a');
+    expect(linkComponent.exists()).toBe(true);
+    expect(linkComponent.prop('href')).toEqual(href);
+  });
+});