Voucher does not redeem any amounts and custom line items doesn't work

[gopeter]

Describe the bug

It seems that there are some incompatibilities between Craft Commerce 5.1 and the Gift Voucher plugin. Adding the voucher to a cart doesn't redeem an amount (it's always 0).

Additionally, I can't add a custom line item (added since Commerce 5.1) once a voucher is applied to the cart:

{
    "name": "Invalid Configuration",
    "message": "Cannot get a purchasable for a custom line item",
    "code": 0,
    "exception": "yii\\base\\InvalidConfigException",
    "file": "/var/www/html/vendor/craftcms/commerce/src/models/LineItem.php",
    "line": 820,
    "trace": [
        {
            "file": "/var/www/html/vendor/verbb/gift-voucher/src/services/Codes.php",
            "line": 245,
            "function": "getPurchasable",
            "class": "craft\\commerce\\models\\LineItem",
            "type": "->"
        },
        {
            "function": "handleValidateLineItem",
            "class": "verbb\\giftvoucher\\services\\Codes",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/base/Event.php",
            "line": 312,
            "function": "call_user_func"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/base/Component.php",
            "line": 650,
            "function": "trigger",
            "class": "yii\\base\\Event",
            "type": "::"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/base/Model.php",
            "line": 386,
            "function": "trigger",
            "class": "yii\\base\\Component",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/base/Model.php",
            "line": 351,
            "function": "beforeValidate",
            "class": "yii\\base\\Model",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/craftcms/commerce/src/elements/traits/OrderValidatorsTrait.php",
            "line": 133,
            "function": "validate",
            "class": "yii\\base\\Model",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/validators/InlineValidator.php",
            "line": 77,
            "function": "validateLineItems",
            "class": "craft\\commerce\\elements\\Order",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/validators/Validator.php",
            "line": 260,
            "function": "validateAttribute",
            "class": "yii\\validators\\InlineValidator",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/base/Model.php",
            "line": 368,
            "function": "validateAttributes",
            "class": "yii\\validators\\Validator",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/craftcms/cms/src/base/Element.php",
            "line": 2666,
            "function": "validate",
            "class": "yii\\base\\Model",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/craftcms/commerce/src/controllers/OrdersController.php",
            "line": 454,
            "function": "validate",
            "class": "craft\\base\\Element",
            "type": "->"
        },
        {
            "function": "actionRefresh",
            "class": "craft\\commerce\\controllers\\OrdersController",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/base/InlineAction.php",
            "line": 57,
            "function": "call_user_func_array"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/base/Controller.php",
            "line": 178,
            "function": "runWithParams",
            "class": "yii\\base\\InlineAction",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/base/Module.php",
            "line": 552,
            "function": "runAction",
            "class": "yii\\base\\Controller",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/craftcms/cms/src/web/Application.php",
            "line": 350,
            "function": "runAction",
            "class": "yii\\base\\Module",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/craftcms/cms/src/web/Application.php",
            "line": 649,
            "function": "runAction",
            "class": "craft\\web\\Application",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/craftcms/cms/src/web/Application.php",
            "line": 312,
            "function": "_processActionRequest",
            "class": "craft\\web\\Application",
            "type": "->"
        },
        {
            "file": "/var/www/html/vendor/yiisoft/yii2/base/Application.php",
            "line": 384,
            "function": "handleRequest",
            "class": "craft\\web\\Application",
            "type": "->"
        },
        {
            "file": "/var/www/html/web/index.php",
            "line": 14,
            "function": "run",
            "class": "yii\\base\\Application",
            "type": "->"
        }
    ]
}

Steps to reproduce

1. Add the voucher to the cart
2. Add a product to the cart
3. Go to the backend and open the cart
4. Click on "add a custom line item"
5. A network error occurs

Craft CMS version

Craft Pro 5.4.4

Plugin version

4.0.3

Multi-site?

Yes

Additional context

Craft Commerce 5.1.1

[engram-design]

Just to clarify - do you mean adding a Gift Voucher to your cart with a custom amount, or do you mean when applying a Gift Voucher Code to your cart? Both are working for me with Commerce 5.1.1.

I'm not surprised a custom line item causes issue though, looking into that.

[gopeter]

Sorry, nevermind the cart thing. Didn't worked because I'm hooking into some recalculation events and broke the gift voucher functionality.

But the custom line item issue still exists. Would be great if could have a look at it! :-)