Prevent firing up the add_to_cart event when clicking in product image

[jorgemd24]

Changes proposed in this Pull Request:

Closes #330

With non-blockified themes, the add_to_cart event's selector is quite broad, leading it to trigger even when a user clicks on the product image.

woocommerce-google-analytics-integration/includes/class-wc-google-gtag-js.php

Line 225 in 487625e

$( '.product.post-" . esc_js( $product->get_id() ) . ' a , .product.post-' . esc_js( $product->get_id() ) . " button' ).on('click', function() {

This PR makes the selector more specific, checking that the link needs to have the class button.

Checks:

• Does your code follow the WordPress coding standards?
• Have you written new tests for your changes, as applicable?
• Have you successfully run tests with your changes locally?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Screenshots:

Detailed test instructions:

1. Use a non-blockified theme, for example store front.
2. Setup the extension with your Google Analytics Tracking ID.
3. Enable all the options of "Enable Enhanced eCommerce" in /wp-admin/admin.php?page=wc-settings&tab=integration&section=google_analytics
4. Install the Google Analytics Chrome extension or use the https://tagassistant.google.com/ to see the events.
5. Open an incognito mode, go to the shop and click the product image. See that the event add_to_cart is not sent.

Additional details:

• PHP unit tests failed but they are fixed here: Update phpunit polyfills to 1.1 #333. Local tests passes if you run composer require --dev yoast/phpunit-polyfills:"^1.1.0" && composer install

Changelog entry

Fix - Prevent firing up the add_to_cart event when clicking in product image

[martynmjones]

Hey @jorgemd24, thanks for your work on this issue.

Tested locally and can confirm the add_to_cart event is only triggered when clicking the add to cart button and unit tests are passing after upgrading the polyfills package so LGTM ✅