# Do NOT run a/b tests over builder! Tracking is completely incorrect

**URL:** <https://forum.builder.io/t/do-not-run-a-b-tests-over-builder-tracking-is-completely-incorrect/6820>\
**Category:** Bugs\
**Tags:** shopify\
**Created:** [November 26, 2024, 8:37am UTC](https://forum.builder.io/t/do-not-run-a-b-tests-over-builder-tracking-is-completely-incorrect/6820 "2024-11-26T08:37:42Z")\
**Posts on this page:** 1\
**Showing post:** 3

<div class="post-metadata">

**Author:** ![pandus1s](https://avatars.discourse-cdn.com/v4/letter/p/f4b2a3/32.png) [@pandus1s](https://forum.builder.io/u/pandus1s)\
**Post date:** [November 29, 2024, 1:12pm UTC](https://forum.builder.io/t/do-not-run-a-b-tests-over-builder-tracking-is-completely-incorrect/6820/3 "2024-11-29T13:12:10Z")

</div>

Looks like we found a solid solution to the problem. The problem is the pixel code suggested here:

> [@Shopify custom pixel for builder to work with checkout extensibility](https://forum.builder.io/t/shopify-custom-pixel-for-builder-to-work-with-checkout-extensibility/4862/5):
>
> hey @cranetrain @sebizox apologies for delay, but this is fully available within Shopify pixels and Builder! It is a newer paradigm so we are in the process of updating our docs but you can see a short loom explanation here: And an example snippet below: analytics.subscribe('checkout\_completed', (event) =\> { // Example for accessing event data const checkout = event.data.checkout; function trackConversion({ amountInfo, meta }) { const eventName = 'conversion'; c…

We threw the Code at Claude and got this one back which tracks 99% of all conversions:

```auto
const BUILDER_STORAGE_KEY = 'builderPendingEvents';
const API_KEY = 'Your API Key';
const MAX_RETRIES = 3;
const RETRY_DELAY = 1000;

// Helper function to safely get storage data
const getPendingEvents = () => {
    try {
        const stored = localStorage.getItem(BUILDER_STORAGE_KEY);
        return stored ? JSON.parse(stored) : [];
    } catch (e) {
        console.error('Error reading pending events:', e);
        return [];
    }
};

// Helper function to safely store data
const storePendingEvent = (eventData) => {
    try {
        const events = getPendingEvents();
        events.push(eventData);
        localStorage.setItem(BUILDER_STORAGE_KEY, JSON.stringify(events));
    } catch (e) {
        console.error('Error storing pending event:', e);
    }
};

// Helper function to remove stored events
const removePendingEvents = () => {
    try {
        localStorage.removeItem(BUILDER_STORAGE_KEY);
    } catch (e) {
        console.error('Error removing pending events:', e);
    }
};

// Function to send tracking data to Builder.io
const sendToBuilder = async (eventData, retryCount = 0) => {
    try {
        const response = await fetch(`https://cdn.builder.io/api/v1/track?apiKey=${API_KEY}`, {
            method: 'POST',
            body: JSON.stringify({ events: [eventData] }),
            headers: {
                'content-type': 'application/json',
            },
            mode: 'cors',
            keepalive: true,
        });

        if (!response.ok) {
            throw new Error(`HTTP error! status: ${response.status}`);
        }

        return true;
    } catch (error) {
        console.error('Tracking error:', error);
        
        if (retryCount < MAX_RETRIES) {
            await new Promise(resolve => setTimeout(resolve, RETRY_DELAY * (retryCount + 1)));
            return sendToBuilder(eventData, retryCount + 1);
        }
        
        // If all retries failed, store the event for later
        storePendingEvent(eventData);
        return false;
    }
};

// Main tracking function
const trackConversion = ({ checkout, amountInfo, meta = {} }) => {
    if (!checkout || !checkout.order || !checkout.order.id) {
        console.error('Invalid checkout data received');
        return;
    }

    const sessionId = document.cookie.split('; ')
        .find(row => row.startsWith('builderSessionId='))
        ?.split('=')[1] || null;
    
    const visitorId = localStorage.getItem('builderVisitorId') || null;

    if (!sessionId || !visitorId) {
        console.warn('Missing sessionId or visitorId');
    }

    const eventData = {
        type: 'conversion',
        data: {
            amount: amountInfo.amount,
            metadata: {
                sdkVersion: '3.2.10',
                url: location.href,
                orderId: checkout.order.id,
                currency: checkout.currencyCode,
                timestamp: new Date().toISOString(),
                ...meta,
            },
            ownerId: API_KEY,
            userAttributes: {
                sessionId,
                visitorId,
            },
            sessionId,
            visitorId,
        },
    };

    return sendToBuilder(eventData);
};

// Setup main event listener
analytics.subscribe('checkout_completed', (event) => {
    trackConversion({
        checkout: event.data.checkout,
        amountInfo: event.data.checkout.totalPrice,
        meta: { 
            additionalData: 'Conversion Recorded',
            eventId: event.id,
            clientId: event.clientId
        },
    });
});

// Try to send pending events on page load
window.addEventListener('load', async () => {
    const pendingEvents = getPendingEvents();
    if (pendingEvents.length > 0) {
        const results = await Promise.all(
            pendingEvents.map(event => sendToBuilder(event))
        );
        
        if (results.every(Boolean)) {
            removePendingEvents();
        }
    }
});

// Backup tracking before page unload
window.addEventListener('beforeunload', () => {
    const pendingEvents = getPendingEvents();
    if (pendingEvents.length > 0) {
        // Use synchronous localStorage to ensure data is saved
        try {
            navigator.sendBeacon(
                `https://cdn.builder.io/api/v1/track?apiKey=${API_KEY}`,
                JSON.stringify({ events: pendingEvents })
            );
            removePendingEvents();
        } catch (e) {
            console.error('Error sending beacon:', e);
        }
    }
});

```

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_[View the full topic](https://forum.builder.io/t/do-not-run-a-b-tests-over-builder-tracking-is-completely-incorrect/6820)._