analytics.js

const METHODS = {
  TRACK: 'track',
  IDENTIFY: 'identify',
};

class AnalyticsService {

	providers = [];

	idenitify(userId, userData) {
		this.callMethod(METHODS.IDENTIFY, [userId, userData]);
	}

	track(event, properties) {
		this.callMethod(METHODS.TRACK, [event, properties]);
	}

	registerProvider(provider) {
		this.providers.push(provider);
	}

	callMethod(method, args) {
		this.providers.map(p => p.handle(method, args));
	}
}

class BaseAnalyticsProvider {
  constructor() {
    if (typeof this.handle !== 'function') {
      throw new TypeError('Method "handle" must be implemented');
    }
  }
}


class GoogleAnalyticsProvider extends BaseAnalyticsProvider {
	constructor(apiKey) {
		super();
		// do some stuff
	}

	handle(method, args) {
		console.log("GA: ", method, args);
	}
}

class AmplitudeAnalyticsProvider extends BaseAnalyticsProvider {
	handle(method, args) {
		console.log("Amplitude: ", method, args);
	}
}



analyticsService = new AnalyticsService();
analyticsService.registerProvider(new GoogleAnalyticsProvider());
analyticsService.registerProvider(new AmplitudeAnalyticsProvider());