Add: Cross-sells for the Store API Cart response.

src/StoreApi/SchemaController.php

@@ -38,7 +38,6 @@ public function __construct( ExtendSchema $extend ) {
 				Schemas\V1\BillingAddressSchema::IDENTIFIER => Schemas\V1\BillingAddressSchema::class,
 				Schemas\V1\ShippingAddressSchema::IDENTIFIER => Schemas\V1\ShippingAddressSchema::class,
 				Schemas\V1\CartShippingRateSchema::IDENTIFIER => Schemas\V1\CartShippingRateSchema::class,
-				Schemas\V1\CartShippingRateSchema::IDENTIFIER => Schemas\V1\CartShippingRateSchema::class,
 				Schemas\V1\CartCouponSchema::IDENTIFIER    => Schemas\V1\CartCouponSchema::class,
 				Schemas\V1\CartFeeSchema::IDENTIFIER       => Schemas\V1\CartFeeSchema::class,
 				Schemas\V1\CartItemSchema::IDENTIFIER      => Schemas\V1\CartItemSchema::class,

src/StoreApi/Schemas/V1/CartSchema.php

@@ -40,6 +40,13 @@ class CartSchema extends AbstractSchema {
 	 */
 	public $coupon_schema;
 
+	/**
+	 * Product item schema instance representing cross-sell items.
+	 *
+	 * @var ProductSchema
+	 */
+	public $cross_sells_item_schema;
+
 	/**
 	 * Fee schema instance.
 	 *
@@ -84,6 +91,7 @@ class CartSchema extends AbstractSchema {
 	public function __construct( ExtendSchema $extend, SchemaController $controller ) {
 		parent::__construct( $extend, $controller );
 		$this->item_schema             = $this->controller->get( CartItemSchema::IDENTIFIER );
+		$this->cross_sells_item_schema = $this->controller->get( ProductSchema::IDENTIFIER );
 		$this->coupon_schema           = $this->controller->get( CartCouponSchema::IDENTIFIER );
 		$this->fee_schema              = $this->controller->get( CartFeeSchema::IDENTIFIER );
 		$this->shipping_rate_schema    = $this->controller->get( CartShippingRateSchema::IDENTIFIER );
@@ -155,6 +163,16 @@ public function get_properties() {
 				'context'     => [ 'view', 'edit' ],
 				'readonly'    => true,
 			],
+			'cross_sells'             => [
+				'description' => __( 'List of cross-sells items related to cart items.', 'woo-gutenberg-products-block' ),
+				'type'        => 'array',
+				'context'     => [ 'view', 'edit' ],
+				'readonly'    => true,
+				'items'       => [
+					'type'       => 'object',
+					'properties' => $this->force_schema_readonly( $this->cross_sells_item_schema->get_properties() ),
+				],
+			],
 			'needs_payment'           => [
 				'description' => __( 'True if the cart needs payment. False for carts with only free products and no shipping costs.', 'woo-gutenberg-products-block' ),
 				'type'        => 'boolean',
@@ -323,6 +341,9 @@ public function get_item_response( $cart ) {
 		// Get shipping packages to return in the response from the cart.
 		$shipping_packages = $has_calculated_shipping ? $controller->get_shipping_packages() : [];
 
+		// Get visible cross sells products.
+		$cross_sells = array_filter( array_map( 'wc_get_product', $cart->get_cross_sells() ), 'wc_products_array_filter_visible' );
+
 		return [
 			'coupons'                 => $this->get_item_responses_from_schema( $this->coupon_schema, $cart->get_applied_coupons() ),
 			'shipping_rates'          => $this->get_item_responses_from_schema( $this->shipping_rate_schema, $shipping_packages ),
@@ -331,6 +352,7 @@ public function get_item_response( $cart ) {
 			'items'                   => $this->get_item_responses_from_schema( $this->item_schema, $cart->get_cart() ),
 			'items_count'             => $cart->get_cart_contents_count(),
 			'items_weight'            => wc_get_weight( $cart->get_cart_contents_weight(), 'g' ),
+			'cross_sells'             => $this->get_item_responses_from_schema( $this->cross_sells_item_schema, $cross_sells ),
 			'needs_payment'           => $cart->needs_payment(),
 			'needs_shipping'          => $cart->needs_shipping(),
 			'has_calculated_shipping' => $has_calculated_shipping,

tests/php/StoreApi/Routes/Cart.php

@@ -5,7 +5,6 @@
 
 namespace Automattic\WooCommerce\Blocks\Tests\StoreApi\Routes;
 
-use Automattic\WooCommerce\Blocks\Tests\StoreApi\Routes\ControllerTestCase;
 use Automattic\WooCommerce\Blocks\Tests\Helpers\FixtureData;
 use Automattic\WooCommerce\Blocks\Tests\Helpers\ValidateSchema;
 
@@ -40,8 +39,21 @@ public function setUp() {
 					'weight'        => 10,
 				)
 			),
+
+			$fixtures->get_simple_product(
+				array(
+					'name'          => 'Test Product 3',
+					'stock_status'  => 'instock',
+					'regular_price' => 10,
+					'weight'        => 10,
+				)
+			),
 		);
 
+		// Add product #3 as a cross-sell for product #1.
+		$this->products[0]->set_cross_sell_ids( array( $this->products[2]->get_id() ) );
+		$this->products[0]->save();
+
 		$this->coupon = $fixtures->get_coupon(
 			array(
 				'code'          => 'test_coupon',
@@ -53,7 +65,7 @@ public function setUp() {
 		wc_empty_cart();
 		$this->keys   = array();
 		$this->keys[] = wc()->cart->add_to_cart( $this->products[0]->get_id(), 2 );
-		$this->keys[] = wc()->cart->add_to_cart( $this->products[1]->get_id(), 1 );
+		$this->keys[] = wc()->cart->add_to_cart( $this->products[1]->get_id() );
 		wc()->cart->apply_coupon( $this->coupon->get_code() );
 
 		// Draft order.
@@ -78,6 +90,11 @@ public function test_get_item() {
 				'items'          => function( $value ) {
 					return count( $value ) === 2;
 				},
+				'cross_sells'    => array(
+					array(
+						'id' => $this->products[2]->get_id(),
+					),
+				),
 				'totals'         => array(
 					'currency_code'               => 'USD',
 					'currency_minor_unit'         => 2,
@@ -475,6 +492,7 @@ public function test_prepare_item() {
 		$this->assertArrayHasKey( 'needs_shipping', $data );
 		$this->assertArrayHasKey( 'items_weight', $data );
 		$this->assertArrayHasKey( 'totals', $data );
+		$this->assertArrayHasKey( 'cross_sells', $data );
 	}
 
 	/**
@@ -483,7 +501,6 @@ public function test_prepare_item() {
 	public function test_get_item_schema() {
 		$routes     = new \Automattic\WooCommerce\StoreApi\RoutesController( new \Automattic\WooCommerce\StoreApi\SchemaController( $this->mock_extend ) );
 		$controller = $routes->get( 'cart', 'v1' );
-		$schema     = $controller->get_item_schema();
 		$cart       = wc()->cart;
 		$response   = $controller->prepare_item_for_response( $cart, new \WP_REST_Request() );
 		$schema     = $controller->get_item_schema();