Mixpanel Mock

March 12, 2014

tl;dr

A tiny CoffeeScript MixpanelMock class stands in for the real mixpanel object and logs each track call to the console. A Rails layout loads the real library only in production and the mock everywhere else.

Key takeaway: Keep analytics events out of development and QA by loading a console-logging mock outside production.

Mixpanel is great for tracking and analyzing user behavior within your application. Here, I will show how to mock out the JavaScript agent to keep from sending events during local development.

When using Mixpanel it’s best not to send events while in development, staging, demo, or QA environments. I created a class to load a mock that will simply log to the console for tracking events.

class MixpanelMock
  track: () ->
      console.log("mixpanel.track", arguments)

window.mixpanel = new MixpanelMock()

You can get the updated source of MixpanelMock on GitHub.

Using in Rails

I usually save the Mixpanel JavaScript Library to a file in vendor/assets/javascripts/mixpanel.js.

Then I place MixpanelMock in vendor/assets/javascripts/mixpanel-mock.coffee.

I use the code below to conditionally load the real or fake Mixpanel library.

- if Rails.env.production?
  = javascript_include_tag "mixpanel"
- else
  = javascript_include_tag "mixpanel-mock"

This way, when not in production, all of your Mixpanel tracking events will simply be printed to the console. This also makes it super simple, as a developer, to know when certain events are being sent to Mixpanel.