Add tests for validation errors in the addEakApplication mutation

[seluianova]

Describe the Problem

We have data validity checks in the init blocks of the application class and its fields.
Such as:

    init {
        if (!onlySelectedIsPresent(entitlementByCardType, cardType)) {
            throw InvalidJsonException("The specified entitlement(s) do not match card type.")
        }
        if ((applicationType != null) != (cardType == BavariaCardType.BLUE)) {
            throw InvalidJsonException("Application type must not be null if and only if card type is blue.")
        }
        if (!wantsPhysicalCard && !wantsDigitalCard) {
            throw InvalidJsonException("Does not apply for a physical nor for a digital card.")
        }
        if (!hasAcceptedPrivacyPolicy) {
            throw InvalidJsonException("Has not accepted privacy policy.")
        }
        if (!givenInformationIsCorrectAndComplete) {
            throw InvalidJsonException("Has not confirmed that information is correct and complete.")
        }
    }

Integration tests should be added to check the response when an invalid application is sent.

In the current approach (see Verein360ApplicationTest class) we create an Application object, serialize it, and send in the request.
But it's not possible to create an application object with invalid values, such as givenInformationIsCorrectAndComplete = false because this will throw an exception.

Describe Your Preferred Solution

We need another approach to generate test requests.
For example, build application as a string, instead of an object?
Or create a fake test application class without init blocks?
Or think of better options.

Describe Possible Alternatives

Probably mock or spy objects can be used

Related Issues

Additional Information