Merge pull request #4320 from woocommerce/dev/PCP-6285-return-cart-id

CreateCartEndpoint always returns the generated cart ID (6285)

Author: stracker-phil

modules/ppcp-store-sync/src/Response/CartResponse.php

@@ -181,7 +181,9 @@ public function to_array(): array {
 			$data['applied_coupons'] = $this->applied_coupons;
 		}
 
-		$data   = array_merge( $data, $this->cart->to_array() );
+		$data       = array_merge( $data, $this->cart->to_array() );
+		$data['id'] = $this->cart_id;
+
 		$totals = $this->calculate_totals();
 
 		if ( $totals ) {

tests/PHPUnit/StoreSync/Response/CartResponseTest.php

@@ -684,6 +684,26 @@ public function test_create_new_excludes_payment_confirmation(): void {
 	// create_completed — status and payment_confirmation
 	// -------------------------------------------------------------------------
 
+	/**
+	 * @scenario Server-generated cart ID is not overwritten by a caller-supplied ID in the request
+	 *           body
+	 *
+	 * Given a PayPal cart built from request body data that already contains an "id" key
+	 * When the response is built via create_new() with a distinct server-generated cart ID
+	 * Then to_array()['id'] equals the server-generated ID
+	 * And the caller-supplied ID from the request body is ignored
+	 */
+	public function test_create_new_id_is_not_overwritten_by_caller_supplied_id(): void {
+		$cart_data       = $this->make_cart_data();
+		$cart_data['id'] = 'client-supplied-id';
+		$cart            = PayPalCart::from_array( $cart_data );
+		$response        = CartResponse::create_new( $cart, 'server-generated-id', 'tok_test' );
+
+		$result = $response->to_array();
+
+		$this->assertSame( 'server-generated-id', $result['id'] );
+	}
+
 	/**
 	 * @scenario Completed checkout sets status to COMPLETED
 	 *