analytics.ts

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/**
 * Document Google Analytics API that is used in the project. These definitions
 * can be updated as more features are used.
 *
 * https://developers.google.com/analytics/devguides/collection/analyticsjs/pages
 */
type GAEvent = {
  hitType: 'event';
  // Specifies the event category. Must not be empty
  eventCategory: string;
  eventAction: string;
  eventLabel?: string;
  eventValue?: number;
};

type GAPageView = {
  hitType: 'pageview';
  page: string;
};

type GATiming = {
  hitType: 'timing';
  timingCategory: string;
  timingVar: string;
  timingValue: number;
  timingLabel?: string;
};

export type GAPayload = GAEvent | GAPageView | GATiming;

export type GAErrorPayload = {
  readonly exDescription: string;
  readonly exFatal: boolean;
};

declare global {
  interface Window {
    // Google Analytics
    ga?: GoogleAnalytics;
  }
}

// Prettier breaks with multiple arrow functions and intersections, so name the arrow
// functions.
type _Send = (command: 'send', payload: GAPayload) => void;
type _Exception = (
  command: 'send',
  type: 'exception',
  payload: GAErrorPayload
) => void;
export type GoogleAnalytics = _Send & _Exception;

export function sendAnalytics(payload: GAPayload) {
  const ga: GoogleAnalytics | undefined = self.ga;
  if (ga) {
    ga('send', payload);
  }
}

export function reportError(errorPayload: GAErrorPayload) {
  const ga: GoogleAnalytics | undefined = self.ga;
  if (ga) {
    ga('send', 'exception', errorPayload);
  }
}