Question: I'm using magento 2.0.7, and what I'm trying to do is to popup the cart(the top right cart ajax minicart) when I add a product to it, Basically trigger it. I have tried to add the "showcart" class to my add to cart button classes, but if I do so, the button just opens the cart, and doesn't add the product anymore..

Answer: 
This is my first answer on this site. I've been struggling trying to make this work for the past two days and I was finally able to make it work, so I though it would be nice to share it.

First of all you need to create a module:

* registration.php
* etc/module.xml
* view/frontend/layout/default.xml
* view/frontend/templates/minicart\_open.phtml
* view/frontend/web/js/view/minicart\_open.js

**Step 1.** You need to add a template to the site. The way to do that is by using the default.xml

```
<referenceContainer name="content">
  <block class="Magento\Framework\View\Element\Template" name="minicart.autoopen" template="Company_ModuleName::minicart_open.phtml"/>
</referenceContainer>

```

**Step 2.** Then inside minicart\_open.phtml we need to call our js file (component) by attaching it to the parent div of the minicart. In this case, [data-block='minicart']. See [this link](http://devdocs.magento.com/guides/v2.0/javascript-dev-guide/javascript/js_init.html) for more details.

```
<script type="text/x-magento-init">
{
     "[data-block='minicart']" : {
        "Company_ModuleName/js/view/minicart_open" : {}
     }
}
</script>

```

**Step 3.** And finally, inside minicart\_open.js, the magic code:

```
define(["jquery/ui","jquery"], function(Component, $){
    return function(config, element){
        var minicart = $(element);
        minicart.on('contentLoading', function () {
            minicart.on('contentUpdated', function () {
                minicart.find('[data-role="dropdownDialog"]').dropdownDialog("open");
            });
        });
    }
});

```

Basically this code extends the functionality of the file `vendor/magento/module-checkout/view/frontend/web/js/view/minicart.js`, and it says that once the AJAX call is completed (contentUpdated), the minicart should be opened.

And that's it, a simple task with a lot of theory behind. Hope it helps.
It is working for Magento 2.3?

I have done the module as suggested but it still not opening the minicart.