Added test for MediatR/Toponyms

[M1R4MI]

Code reviewers

• @Mult1pers
• @Exlizardium
• @emil720a1
• @TakerTrip
• @skorpionreser
• @Loki22978964
• @Laminate32

Second Level Review

• @DrFaust555

Summary of issue

MediatR/Toponyms handlers did not have unit tests. Their successful, failure, not-found and empty-result execution paths were not covered.

Summary of change

• GetToponymsByStreetcodeIdHandlerTests
• GetToponymByIdHandlerTest
• GetAllToponymItemsHandlerTests

The tests cover:

• successful results;
• missing Toponym and Streetcode entities;
• empty toponym collections;
• repository interactions;
• AutoMapper calls;

Testing approach

Executed all Toponyms unit tests with:

     dotnet test Streetcode.XUnitTest/Streetcode.XUnitTest.csproj \
           --filter "FullyQualifiedName~Streetcode.XUnitTest.MediatRTests.Toponyms"

Closes #27

CHECK LIST

• СI passed
• Сode coverage >=95%
• PR is reviewed manually again (to make sure you have 100% ready code)
• All reviewers agreed to merge the PR
• I've checked new feature as logged in and logged out user if needed
• PR meets all conventions

[DrFaust555]

Handle_WhenTitleProvided_ShouldFilterAndDistinctByStreetName doesn't actually test filtering. The mapper is stubbed with It.IsAny<IEnumerable>() and returns a ready-made single-item list, and the assertions then check that list - so they're checking the mock, not the handler. The test would still pass if FindStreetcodesWithMatchTitle were deleted.

It matters here, because with that data the handler really returns four toponyms, not one: the Where matches "First Street", "first street", "fIrst strEet" and "FirSt StreeT", and then GroupBy(s => s.StreetName) is case-sensitive, so those are four separate keys. Your data was clearly written to check case-insensitive dedup, and that isn't what the handler does.

The commented-out capturedItems/Callback block is exactly the tool for this - worth finishing rather than removing:

IEnumerable<Toponym>? captured = null;
_mapperMock
    .Setup(m => m.Map<IEnumerable<ToponymDTO>>(It.IsAny<IEnumerable<Toponym>>()))
    .Callback<object>(o => captured = ((IEnumerable<Toponym>)o).ToList())
    .Returns(expectedDtos);
...
Assert.Single(captured!);

That will fail, and it's a useful failure - then either adjust the data to the actual behaviour or open a separate task to group by StreetName.ToLower().

[Laminate32]

1. In GetToponymsByStreetcodeIdHandlerTests you mock the mapper for a single Toponym object (It.IsAny<Toponym>()). If your handler maps the collection directly (e.g., _mapper.Map<IEnumerable<ToponymDTO>>(toponyms)), this mock will fail. Change it to mock IEnumerable<Toponym> to IEnumerable<ToponymDTO>, just like you did in the GetAll tests

2. In Handle_WhenToponymRepositoryReturnsNull_ShouldReturnFailure you test for a null return from the repository. Entity Framework Core typically returns an empty list ([]), not null, when no records are found. You should add a test simulating an empty collection and ensure your handler checks !toponyms.Any()

[emil720a1]

A few things still need attention:

Handle_WhenTitleProvided_ShouldFilterAndDistinctByStreetName groups capturedItems again inside the assertion, so the test passes even though the handler sends four differently-cased items to the mapper. Please verify the handler output directly with Assert.Single(capturedItems!), then either adjust the test data or track case-insensitive deduplication separately.
The tests use It.IsAny for repository predicates. Please verify that GetToponymById and GetToponymsByStreetcodeId actually use the requested IDs.
GetAllAsync() returns an empty collection when nothing is found, not null. Please add an empty-collection scenario and clarify whether it should return success or failure.

[sonarqubecloud]

Quality Gate failed

Failed conditions
0.0% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud