Automated Tests for GTM Data Layer Push Events

Automated Tests or Manual Tests for Your Data Layer Events?

Choosing between manual and automated testing for your Data Layer events depends on your scale and requirements. Let’s explore both approaches to help you make an informed decision.

Manual Testing Methods

Testing via Browser Console

The fastest way to audit your current Data Layer object is to type window.dataLayer in your browser’s DevTools console. This gives you immediate access to all events sent to the Data Layer on the current page.

Note: If you’re using a custom Data Layer name, use window.customDataLayerName instead.

This method provides a quick snapshot but becomes cumbersome when you need to track events across multiple pages or complex user journeys.

Using Chrome Extension Debuggers

Browser extensions like AH Debugger significantly streamline the debugging process. It offers two complementary views:

1. Console Stream: Log Real-time event monitoring as they occur in your console
2. Extension Panel: Access to advanced debugging capabilities including built-in tests and search through events

This dual-view approach makes it much faster to locate and analyze specific events without scrolling through lengthy logs/network request panel.

The Case for Automation

If you’re reading this, you probably understand the time investment required for proper Data Layer regression testing.

Whether you use debugger extensions like AH Debugger or rely on window.dataLayer in your console, manual testing becomes difficult to scale. Consider these challenges:

• Multiple Websites: How do you efficiently test across different properties?
• Event Complexity: What happens when you have dozens of events and numerous user journeys?
• Consistency: How do you ensure testing coverage remains comprehensive as your implementation grows?

Why Not DIY Automation?

If you’re technically inclined, you might consider building your own solution using JavaScript. While possible, this approach has significant drawbacks:

• Each website requires custom implementation
• Maintenance becomes tedious as requirements evolve
• Basic checks (like verifying GTM loads) are relatively simple, but comprehensive event validation is complex

The AI Testing Trap

Using AI for Data Layer testing might seem attractive, but it introduces problems:

• Token Costs: Each event validation requires substantial context, leading to high token consumption and costs that scale with your event count
• Reliability: AI hallucinations can produce false positives or miss critical issues
• Consistency: Results may vary between test runs

Setting Up Automated Tests with AssertionHub

AssertionHub eliminates the need for coding knowledge while providing comprehensive Data Layer testing. You can create reusable tests that work across multiple websites without recreating them for each property.

How to Start Automating Your Data Layer Events

After starting your free trial, follow these steps to record your first user journey:

Think of it like simulating an actual user’s path through your website.

1. Create New User Journey: Click “New User Journey”
2. Record Your Session:
   • Enter the website URL to record
   • Start your recording
   • The right panel displays detected Google Tag Manager Data Layer push events
3. Select Events to Monitor:
   • Choose the events you want to track
   • Click to create a test for each event
4. Configure Tests:
   • Choose the metrics you want to validate
   • Save your configuration
5. Finalize Recording:
   • Complete your recording
   • Add the test for each Data Layer event on the step where you expect it to fire
6. Run and Review:
   • Execute your user journey
   • Review the test results

Optional: Continuous Monitoring

For ongoing validation, you can:

• Schedule user journeys to run daily
• Add your email for notifications
• Integrate with Slack for team alerts

This ensures your Data Layer implementation remains reliable as your website evolves, without manual intervention.