LocalizedException is catched and overwritten with a generalized one in placeOrder

[rzinnatullin]

Preconditions

1. Magento 2.1.6
2. Php 7
3. Ubuntu 16.04

Description

I'm creating a module that is subscribed to 'checkout_submit_before' event. In the event handler I'm doing some address validations and in case of issues I'm throwing LocalizedException exception.
However, my exception is catched and overwritten with CouldNotSaveException exception:

As the result, user sees that generalized exception:

I suppose that the catch block should rethrow LocalizedException. There are a lot of places inside placeOrder where LocalizedException could be thrown:

Note that 'Please check the shipping address information' wouldn't be displayed to the user.

If I'm doing this wrong, can you please suggest a good way to show validation errors to the user.

Expected result

I did very simple fix to get what I want:

After that I'm getting exactly the behaviour I wanted:

Any thought?

[YevSent]

Hi, @rzinnatullin, Magento provides the only general error message for exceptions. On the one hand, it allows making an application more secure on the other hand customer can't see useful error details like incorrect address or credit card number.

If I'm doing this wrong, can you please suggest a good way to show validation errors to the user.

You can add own implementation of \Magento\Checkout\Api\PaymentInformationManagementInterface and \Magento\Checkout\Api\GuestPaymentInformationManagementInterface, override preference for them and show error messages at your own risk.

This issue the same as #9003.

[hostep]

I think this duplicates #6795 and #6246
In the second one, you can find a commit where they have it already fixed on the develop branch, but I don't think it's already backported to 2.1.x

[YevSent]

@hostep, the develop branch does not have any fixes for this behavior only logging of original exception was added.

[hostep]

@joni-jones: Ok thanks for the clarification, good to know!

[rzinnatullin]

Hi @joni-jones,

You can add own implementation of \Magento\Checkout\Api\PaymentInformationManagementInterface and \Magento\Checkout\Api\GuestPaymentInformationManagementInterface, override preference for them and show error messages at your own risk.

Is there any other way to do Address validation during Checkout? I don't want to replace Magento's functionality, I want to extend it.

[YevSent]

You can try to use plugins for savePaymentInformationAndPlaceOrder to analyze original exception and process customizations.

[rzinnatullin]

Thanks @joni-jones, I've got your idea.

Regarding the original issue - as I understand Magento 2 developers are not going to do something similar to what I did (rethrow LocalizedException)? I'm asking because I thought that LocalizedException has been introduced specifically to add an ability to send a error message to frontend (a user).