Introduce placeholder express methods

.eslintrc.js

@@ -1,4 +1,5 @@
 module.exports = {
     extends: './vendor/magento/magento-coding-standard/eslint/.eslintrc',
+    ignorePatterns: ['view/frontend/web/js/checkout'],
     root: true
 };

Plugin/CustomerData/AddAdyenExpressMethods.php

@@ -0,0 +1,76 @@
+<?php
+declare(strict_types=1);
+
+namespace BlueFinch\CheckoutAdyen\Plugin\CustomerData;
+
+use Adyen\Payment\Api\AdyenPaymentMethodManagementInterface;
+use Magento\Checkout\CustomerData\Cart as Subject;
+use Magento\Checkout\Model\Session;
+use Magento\Framework\App\Config\ScopeConfigInterface;
+use Magento\Store\Model\ScopeInterface;
+
+class AddAdyenExpressMethods
+{
+    public const PAYMENT_METHODS_KEY = 'bluefinch_adyen_payment_methods';
+
+    /**
+     * @var AdyenPaymentMethodManagementInterface
+     */
+    private $adyenPaymentMethodManagement;
+
+    /**
+     * @var Session
+     */
+    private $checkoutSession;
+
+    /**
+     * @var ScopeConfigInterface
+     */
+    private $scopeConfig;
+
+    /**
+     * Cart constructor
+     *
+     * @param AdyenPaymentMethodManagementInterface $adyenPaymentMethodManagement
+     * @param Session $checkoutSession
+     * @param ScopeConfigInterface $scopeConfig
+     */
+    public function __construct(
+        AdyenPaymentMethodManagementInterface $adyenPaymentMethodManagement,
+        Session $checkoutSession,
+        ScopeConfigInterface $scopeConfig
+    ) {
+        $this->adyenPaymentMethodManagement = $adyenPaymentMethodManagement;
+        $this->checkoutSession = $checkoutSession;
+        $this->scopeConfig = $scopeConfig;
+    }
+
+    /**
+     * Intercept getSectionData and Adyen Payment methods.
+     *
+     * @param Subject $subject
+     * @param array $result
+     * @return array
+     */
+    public function afterGetSectionData(
+        Subject $subject,
+        array $result
+    ): array {
+        $googlePayExpressEnabled = $this->scopeConfig->getValue('payment/adyen_googlepay/express_show_on', ScopeInterface::SCOPE_STORE);
+        $applePayExpressEnabled = $this->scopeConfig->getValue('payment/adyen_applepay/express_show_on', ScopeInterface::SCOPE_STORE);
+        $payPalExpressEnabled = $this->scopeConfig->getValue('payment/adyen_paypal_express/express_show_on', ScopeInterface::SCOPE_STORE);
+
+        // Only run if no Adyen Express methods are enabled otherwise we'd be duplicating the Adyen API request.
+        if (!$googlePayExpressEnabled && !$applePayExpressEnabled && !$payPalExpressEnabled) {
+            $quoteId = $this->checkoutSession->getQuoteId();
+            $paymentMethods = $quoteId ?
+                json_decode(
+                    $this->adyenPaymentMethodManagement->getPaymentMethods($quoteId),
+                    true
+                ) : [];
+            $result[self::PAYMENT_METHODS_KEY] = $paymentMethods;
+        }
+
+        return $result;
+    }
+}

Plugin/CustomerData/Cart.php

@@ -0,0 +1,29 @@
+<?php
+declare(strict_types=1);
+
+namespace BlueFinch\CheckoutAdyen\Plugin\CustomerData;
+
+use BlueFinch\CheckoutAdyen\Plugin\CustomerData\AddAdyenExpressMethods;
+use Adyen\ExpressCheckout\Plugin\CustomerData\Cart as Subject;
+
+class Cart
+{
+    /**
+     * If the Adyen Express has already added the payment methods then we can set use them without having
+     * to call Adyen's API again.
+     *
+     * @param Subject $subject
+     * @param array $result
+     * @return array
+     */
+    public function afterAfterGetSectionData(
+        Subject $subject,
+        array $result
+    ): array {
+        if (isset($result[Subject::PAYMENT_METHODS_KEY])) {
+            $result[AddAdyenExpressMethods::PAYMENT_METHODS_KEY] = $result[Subject::PAYMENT_METHODS_KEY];
+        }
+
+        return $result;
+    }
+}

composer.json

@@ -13,15 +13,17 @@
   },
   "require": {
     "magento/framework": "*",
-    "bluefinchcommerce/module-checkout": "^1.0"
+    "bluefinchcommerce/module-checkout": "^1.0",
+    "adyen/module-payment": ">7.0.0"
   },
   "require-dev": {
-    "magento/magento-coding-standard": "*",
+    "magento/magento-coding-standard": "<=35",
     "phpcompatibility/php-compatibility": "*",
     "phpunit/phpunit": "*",
     "phpstan/phpstan": "^1.9",
     "squizlabs/php_codesniffer": "^3.6",
-    "dealerdirect/phpcodesniffer-composer-installer": "^1.0"
+    "dealerdirect/phpcodesniffer-composer-installer": "^1.0",
+    "adyen/adyen-magento2-expresscheckout": "^2.4"
   },
   "repositories": {
     "magento": {