src/ShopifyApp/ShopifyApp.php
public function sanitizeShopDomain($domain)
    {
        if (empty($domain)) {
            return;
        }

        $configEndDomain = Config::get('shopify-app.myshopify_domain');
        $domain = strtolower(preg_replace('/https?:\/\//i', '', trim($domain)));

        if (strpos($domain, $configEndDomain) === false && strpos($domain, '.') === false) {
            // No myshopify.com ($configEndDomain) in shop's name
            $domain .= ".{$configEndDomain}";
        }

        // Return the host after cleaned up
        return parse_url("http://{$domain}", PHP_URL_HOST);
    }
public function sanitizeShopDomain($domain)
    {
        if (empty($domain)) {
            return;
        }

        $configEndDomain = Config::get('shopify-app.myshopify_domain');
        $domain = strtolower(preg_replace('/https?:\/\//i', '', trim($domain)));

        if (strpos($domain, $configEndDomain) === false && strpos($domain, '.') === false) {
            // No myshopify.com ($configEndDomain) in shop's name
            $domain .= ".{$configEndDomain}";
        }

        // Return the host after cleaned up
        return parse_url("http://{$domain}", PHP_URL_HOST);
    }
Ensures shop domain meets the specs.

@param string $domain The shopify domain

@return string