Add failure and exception case test coverage for EstateDomainService

[Copilot]

EstateDomainServiceTests only covered happy paths. Each method in EstateDomainService has multiple early-return failure branches (aggregate fetch failure, domain state validation failure, save failure) and a top-level exception handler that were entirely untested.

New failure case tests

CreateEstate

• GetAggregateOrFailure returns failure
• estateAggregate.Create() fails (empty estate name)
• AggregateService.Save() fails

AddOperatorToEstate

• Get<OperatorAggregate> returns failure
• GetLatest<EstateAggregate> returns failure
• estateAggregate.AddOperator() fails (estate not yet created)
• AggregateService.Save() fails

CreateEstateUser

• GetLatest<EstateAggregate> returns failure
• estateAggregate.AddSecurityUser() fails (estate not yet created)
• AggregateService.Save() fails

RemoveOperatorFromEstate

• GetLatest<EstateAggregate> returns failure
• estateAggregate.RemoveOperator() fails (estate not created / operator not added)
• AggregateService.Save() fails

Each test follows the established pattern — mock the relevant dependency to return Result.Failure() or use an EmptyEstateAggregate to trigger domain validation failure, then assert result.IsFailed.

New exception case tests

Each method also has a catch (Exception ex) block that returns Result.Failure(ex.GetExceptionMessages()). One test per method covers this path by configuring the first dependency call to throw an Exception:

• EstateDomainService_CreateEstate_ExceptionThrown_ResultIsFailed
• EstateDomainService_AddOperatorToEstate_ExceptionThrown_ResultIsFailed
• EstateDomainService_CreateEstateUser_ExceptionThrown_ResultIsFailed
• EstateDomainService_RemoveOperatorFromEstate_ExceptionThrown_ResultIsFailed

Original prompt

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This section details on the original issue you should resolve

<issue_title>Update Test Coverage on Estate Domain service</issue_title>
<issue_description>Each domain service method needs new tests added to cover all failure cases, for example here is the Create Estate method

</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Update Test Coverage on Estate Domain service #910

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[StuartFerguson]

@copilot what about the exception cases ?

[Copilot]

@copilot what about the exception cases ?

Added four exception-case tests in commit a81228e — one per method — each using .ThrowsAsync(new Exception()) on the first dependency to exercise the catch (Exception ex) { return Result.Failure(ex.GetExceptionMessages()); } block in every method.