✅ CommandHandlers_Should_FollowRules
✅ QueryHandlers_Should_FollowRules

✅ CommandHandlers_May_UseReadRepositories
✅ CommandHandlers_Should_UpdateCache
✅ CommandHandlers_Should_UseWriteRepositories
✅ Commands_Should_ImplementICommand
✅ Queries_Should_ImplementIQuery
✅ QueryHandlers_Should_NotUseWriteRepositories
✅ QueryHandlers_Should_UseReadRepositories

✅ AggregateRoots_Should_FollowRules

✅ DomainEvents_Should_FollowRules
✅ Entities_Should_FollowRules
✅ ValueObjects_Should_BeImmutable

✅ ApplicationSpecifications_Should_ImplementISpecification
✅ DomainSpecifications_Should_ImplementISpecification
✅ DomainSpecifications_Should_NotReferenceReadModels
✅ EntitySpecifications_Should_BeInDomainNamespace
✅ EvaluatorSpecifications_Should_BeInInfrastructureLayer
✅ ReadModelSpecifications_Should_BeInApplicationNamespace
✅ Specifications_Should_BeSealed
✅ SpecificationsForDomainEntities_Should_NotBeInApplicationLayer

✅ CacheInterfaces_Should_BeInApplicationLayer
✅ CacheInterfaces_Should_SpecifyReadModels
✅ Caches_Should_BeInInfrastructureLayer
✅ Caches_Should_BeSealed
✅ Caches_Should_DependOnReadModels
✅ Caches_Should_NotDependOnDomainEntities

✅ ApplicationReadDbContext_Should_DependOnReadModels
✅ ApplicationWriteDbContext_Should_DependOnDomainEntities
✅ ReadDbContext_Should_BeSealed
✅ ReadDbContext_Should_InheritFromBaseDbContext
✅ ReadDbContext_Should_NotDependOnDomainEntities
✅ WriteDbContext_Should_InheritFromBaseDbContext
✅ WriteDbContext_Should_NotDependOnReadModels

✅ ApplicationSpecifications_Should_BeInApplicationLayer
✅ DomainSpecifications_Should_BeInDomainLayer
✅ ReadRepositories_Should_BeInReadRepositoriesNamespace
✅ ReadRepositories_Should_ImplementCorrectInterface
✅ ReadRepositories_Should_NotDependOnWriteDbContext
✅ ReadRepositories_Should_NotUseAppDbContext
✅ ReadRepositories_Should_UseApplicationReadDbContext
✅ Repositories_Should_BeSealed
✅ WriteRepositories_Should_BeInWriteRepositoriesNamespace
✅ WriteRepositories_Should_ImplementCorrectInterface
✅ WriteRepositories_Should_NotDependOnReadDbContext
✅ WriteRepositories_Should_NotUseAppDbContext
✅ WriteRepositories_Should_UseApplicationWriteDbContext

✅ ApplicationLayer_ShouldNot_HaveDependencyOn_InfrastructureLayer
✅ ApplicationLayer_ShouldNot_HaveDependencyOn_PresentationLayer
✅ DomainLayer_ShouldNot_HaveDependencyOn_ApplicationLayer
✅ DomainLayer_ShouldNot_HaveDependencyOn_InfrastructureLayer
✅ InfrastructureLayer_ShouldNot_HaveDependencyOn_PresentationLayer

✅ CommandHandlers_Should_BeSealed
✅ CommandHandlers_Should_UseWriteRepositories
✅ QueryHandlers_Should_BeSealed
✅ QueryHandlers_Should_NotUseWriteRepositories
✅ QueryHandlers_Should_UseReadRepositories

✅ ReadRepositories_Should_UseReadModels
✅ WriteRepositories_Should_UseEntitiesImplementingIAggregateRoot

✅ Cache_Should_StoreAndRetrieveReadModels
✅ CacheShouldReflectChangesWhenEntityIsUpdated
✅ CacheShouldReturnNullAfterEntityIsDeleted
✅ ExpireAsync_Should_ExpireBrandFromCache
✅ GetOrSetByIdAsync_Should_ReturnNull_When_BrandDoesNotExist
✅ GetOrSetByIdAsyncShouldReturnBrandReadModelWhenBrandExists
✅ RemoveAsync_Should_RemoveBrandFromCache
✅ SetAsync_Should_StoreBrandReadModelInCache

✅ AnyAsync_Should_ReturnFalseWhenBrandDoesNotExist
✅ AnyAsync_Should_ReturnTrueWhenBrandExists
✅ CountAsync_Should_ReturnCorrectCount
✅ FirstOrDefaultAsync_Should_ReturnBrandBySpecification
✅ GetByIdAsync_Should_ReturnCorrectBrandReadModel
✅ ListAsync_Should_ReturnAllBrands
✅ ListAsync_WithPaginationSpecification_Should_ReturnPagedResults

✅ AddAndFindById_Should_WorkCorrectly
✅ Delete_Should_RemoveBrand
✅ ExistsWithName_Should_ReturnFalseForNonExistentName
✅ ExistsWithName_Should_ReturnTrueForExistingName
✅ FindByName_Should_ReturnCorrectBrand
✅ FindBySpecification_Should_ReturnCorrectBrand
✅ Update_Should_PersistChanges

✅ GetAllCategories_Should_ReturnAllCategories
✅ GetById_ReadModel_ReturnsCategory

✅ AddAndGetCategory_Works
✅ GetByName_Should_ReturnCategory
✅ Update_Should_PersistChanges

✅ GetAllProductPriceTypes_Should_ReturnAllTypes

✅ AddAndGetProductPriceType_Works
✅ Update_Should_PersistChanges

✅ GetAllAsyncShouldReturnAllProducts
✅ GetByIdAsyncShouldReturnCorrectProductReadModel
✅ GetBySkuAsyncShouldReturnCorrectProduct

✅ AddAndFindByIdShouldWorkCorrectly
✅ DeleteShouldRemoveProduct
✅ FindBySkuShouldReturnCorrectProduct
✅ UpdateShouldPersistChanges

✅ ReadModel_GetById_ReturnsSeededModel

✅ AddAndGetPromotion_Works
✅ GetActivePromotions_Should_ReturnOnlyActivePromotions
✅ GetByName_Should_ReturnPromotion
✅ Update_Should_PersistChanges

✅ GetAllAsyncShouldReturnAllSuppliers
✅ GetByIdAsyncShouldReturnCorrectSupplierReadModel

✅ AddAndGetSupplier_Works
✅ GetAllSuppliers_Should_ReturnAllSuppliers
✅ GetByName_Should_ReturnSupplier
✅ Update_Should_PersistChanges

✅ BrandToBrandResponse_Maps_All_Properties
✅ PagedBrandToPagedBrandResponse_Maps_All_Properties

✅ HandleShouldReturnErrorWhenBrandIsInvalidAsync
✅ HandleShouldReturnSuccessResultWhenBrandIsUniqueAsync

✅ Handle_Should_ReturnDeletedResult_WhenBrandIsDeleted_Async
✅ Handle_Should_ReturnNotFoundResult_WhenBrandIsNotFound_Async
✅ Handle_Should_Throw_WhenCacheThrows_Async
✅ Handle_Should_Throw_WhenRepositoryThrows_Async
✅ Handle_Should_Throw_WhenUnitOfWorkThrows_Async

✅ Handle_Should_ReturnDeletedResult_WhenBrandsIsDeleted_Async

✅ Handle_Should_ReturnNotFoundResult_WhenBrandIsNull_Async
✅ Handle_Should_ReturnSuccessResult_WhenBrandIsNotNull_Async

✅ Handle_Should_ReturnEmptyBrandResponseList_WhenBrandsIsFound_Async

✅ BrandResponseAllowsNulls
✅ BrandResponseCanSetAllProperties
✅ BrandResponseDefaultsAreCorrect

✅ Handle_Should_ReturnNotFoundResult_WhenBrandIsNotFound_Async
✅ Handle_Should_ReturnSuccessResult_WhenBrandIsUpdated_Async

✅ CategoryResponse_Allows_Nulls
✅ CategoryResponse_CanSet_All_Properties
✅ CategoryResponse_Defaults_Are_Correct

✅ ProductPriceResponse_Allows_Nulls
✅ ProductPriceResponse_CanSet_All_Properties
✅ ProductPriceResponse_Defaults_Are_Correct

✅ Handle_Should_ReturnError_WhenProductNameIsEmpty
✅ Handle_Should_ReturnError_WhenProductSkuIsEmpty
✅ Handle_Should_ReturnNotCreated_WhenSaveChangesReturnsZero
✅ Handle_Should_ReturnProductResponse_WhenProductIsCreated

✅ Handle_Should_ReturnNotFound_WhenProductDoesNotExist
✅ Handle_Should_ReturnProductResponse_WhenProductExists

✅ ProductToProductResponse_Maps_All_Properties

✅ CreateProductRequest_CanSetProperties
✅ CreateProductRequest_Default_Properties
✅ GetProductByIdRequest_CanSetProductId
✅ GetProductByIdRequest_Default_Properties

✅ ProductResponse_Allows_Nulls_And_Empty_Collections
✅ ProductResponse_CanSet_All_Properties
✅ ProductResponse_Defaults_Are_Correct

✅ CreateProductValidator_Should_Fail_On_Empty_ProductSku
✅ CreateProductValidator_Should_Fail_When_ProductSku_Already_Exists
✅ GetProductByIdValidator_Should_Fail_On_Default_Guid
✅ GetProductByIdValidator_Should_Fail_On_Empty_ProductId
✅ GetProductByIdValidator_Should_Pass_On_Valid_ProductId

✅ PromotionResponse_CanSet_All_Properties
✅ PromotionResponse_Defaults_Are_Correct

✅ EmptyDescription_Should_Have_Correct_Code_And_Description
✅ EmptyName_Should_Have_Correct_Code_And_Description
✅ EmptyWebsite_Should_Have_Correct_Code_And_Description
✅ InvalidWebsite_Should_Have_Correct_Code_And_Description
✅ NotFound_Should_Have_Correct_Code_And_Description

✅ Create_MultipleFields_Invalid(name: " ", description: " ", website: "not-a-url", expectError: True, errorCount: 3)
✅ Create_MultipleFields_Invalid(name: null, description: null, website: "https://example.com", expectError: True, errorCount: 2)
✅ Create_MultipleFields_Invalid(name: null, description: null, website: null, expectError: True, errorCount: 2)
✅ Create_Name_Description_Validation(name: "   ", description: "   ", expectError: True)
✅ Create_Name_Description_Validation(name: "   ", description: "Desc", expectError: True)
✅ Create_Name_Description_Validation(name: "Name", description: "   ", expectError: True)
✅ Create_Name_Description_Validation(name: "Name", description: null, expectError: True)
✅ Create_Name_Description_Validation(name: null, description: "Desc", expectError: True)
✅ Create_Name_Description_Validation(name: null, description: null, expectError: True)
✅ Create_Should_Fail_When_AllFieldsNullOrEmpty
✅ Create_Should_ReturnAllErrors_When_MultipleFieldsInvalid
✅ Create_Should_ReturnError_When_DescriptionIsInvalid(invalidDescription: "   ")
✅ Create_Should_ReturnError_When_DescriptionIsInvalid(invalidDescription: "")
✅ Create_Should_ReturnError_When_DescriptionIsInvalid(invalidDescription: null)
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: "   ")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: "")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: null)
✅ Create_Should_ReturnError_When_WebsiteIsMalformed(badWebsite: "ftp://badurl")
✅ Create_Should_ReturnError_When_WebsiteIsMalformed(badWebsite: "http:/missing-slash.com")
✅ Create_Should_ReturnError_When_WebsiteIsMalformed(badWebsite: "not-a-url")
✅ Create_Should_ReturnMultipleErrors_When_MultipleFieldsInvalid
✅ Create_Should_SetCorrectProperties
✅ Create_Should_Succeed_When_WebsiteIsNull
✅ Create_Should_Succeed_With_Uppercase_Http_Or_Https
✅ Create_WithNullWebsite_Should_SetWebsiteToNull
✅ Create_WithOnlyWebsite_Should_ReturnErrorsForNameAndDescription
✅ Create_WithValidWebsite_Should_SetWebsite
✅ Products_Should_Always_BeInitialized
✅ Products_Should_BeSameInstance_AfterUpdate
✅ Update_AllFieldsToWhitespace_Should_ReturnAllErrors
✅ Update_FromNullWebsite_ToValidWebsite_Should_SetWebsite
✅ Update_FromWebsite_ToNull_Should_ReturnError_And_NotChangeWebsite
✅ Update_Name_Description_Website_Various(updateName: "", updateDescription: null, updateWebsite: null, expectedName: "Name", expectedDescription: "Desc", expectedWebsiteResult: "https://example.com", expectError: True)
✅ Update_Name_Description_Website_Various(updateName: null, updateDescription: "", updateWebsite: null, expectedName: "Name", expectedDescription: "Desc", expectedWebsiteResult: "https://example.com", expectError: True)
✅ Update_Name_Description_Website_Various(updateName: null, updateDescription: "NewName", updateWebsite: null, expectedName: "Name", expectedDescription: "NewName", expectedWebsiteResult: "https://example.com", expectError: False)
✅ Update_Name_Description_Website_Various(updateName: null, updateDescription: null, updateWebsite: "https://newsite.com", expectedName: "Name", expectedDescription: "Desc", expectedWebsiteResult: "https://newsite.com", expectError: False)
✅ Update_Name_Description_Website_Various(updateName: null, updateDescription: null, updateWebsite: "NewDesc", expectedName: "Name", expectedDescription: "Desc", expectedWebsiteResult: "https://example.com", expectError: True)
✅ Update_Should_NotAddEvents
✅ Update_Should_NotAddEvents_When_ValuesChanged
✅ Update_Should_NotChange_Properties_When_ValuesAreNull
✅ Update_Should_NotChange_When_ValuesAreSame
✅ Update_Should_OnlyModifyChangedProperties
✅ Update_Should_RemoveDescription_When_EmptyString
✅ Update_Should_RemoveWebsite_When_EmptyString
✅ Update_Should_ReturnAllErrors_When_MultipleFieldsInvalid
✅ Update_Should_ReturnError_When_WebsiteIsInvalid
✅ Update_Should_ReturnMultipleErrors_When_MultipleFieldsInvalid
✅ Update_Should_Succeed_When_AllFieldsNull
✅ Update_Should_UpdateAllFields_When_AllProvided
✅ Update_Website_VariousCases(initialWebsite: "https://example.com", updateWebsite: "   ", expectedWebsite: "https://example.com", expectError: True)
✅ Update_Website_VariousCases(initialWebsite: "https://example.com", updateWebsite: "", expectedWebsite: "https://example.com", expectError: True)
✅ Update_Website_VariousCases(initialWebsite: "https://example.com", updateWebsite: "https://example.com", expectedWebsite: "https://example.com", expectError: False)
✅ Update_Website_VariousCases(initialWebsite: "https://example.com", updateWebsite: "not-a-url", expectedWebsite: "https://example.com", expectError: True)
✅ Update_Website_VariousCases(initialWebsite: "https://example.com", updateWebsite: null, expectedWebsite: "https://example.com", expectError: False)
✅ Update_Website_VariousCases(initialWebsite: null, updateWebsite: "   ", expectedWebsite: null, expectError: True)
✅ Update_Website_VariousCases(initialWebsite: null, updateWebsite: "https://newsite.com", expectedWebsite: "https://newsite.com", expectError: False)
✅ Update_WithAllValuesUnchanged_Should_NotAlterState_OrAddEvents
✅ Update_WithEmptyDescription_Should_ReturnError_And_NotChangeDescription
✅ Update_WithEmptyName_Should_ReturnError_And_NotChangeName
✅ Update_WithInvalidWebsite_Should_ReturnError_And_NotChangeWebsite
✅ Update_WithNullWebsite_Should_NotChangeWebsite
✅ Update_WithOnlyDescriptionChanged_Should_OnlyUpdateDescription
✅ Update_WithOnlyNameChanged_Should_OnlyUpdateName
✅ Update_WithOnlyWebsiteChanged_Should_OnlyUpdateWebsite
✅ Update_WithSameWebsite_Should_NotChangeWebsite
✅ Update_WithValidWebsite_Should_SetWebsite
✅ Update_WithWhitespaceWebsite_Should_ReturnError
✅ Update_WithWhitespaceWebsite_When_WebsiteIsNotNull_Should_ReturnError_And_NotChange
✅ Update_WithWhitespaceWebsite_When_WebsiteIsNull_Should_ReturnError_And_NotChange
✅ Website_Should_ReturnError_When_InvalidUrl

✅ Create_Should_ReturnEmptyError_When_NullOrWhitespace(value: "   ")
✅ Create_Should_ReturnEmptyError_When_NullOrWhitespace(value: "")
✅ Create_Should_ReturnEmptyError_When_NullOrWhitespace(value: null)
✅ Create_Should_ReturnInvalidError_When_NotValidUrl(value: "ftp://example.com")
✅ Create_Should_ReturnInvalidError_When_NotValidUrl(value: "http:/missing-slash.com")
✅ Create_Should_ReturnInvalidError_When_NotValidUrl(value: "not-a-url")
✅ Create_Should_ReturnInvalidError_When_NotValidUrl(value: "www.example.com")
✅ Create_Should_Succeed_When_ValidUrl(value: "http://example.com")
✅ Create_Should_Succeed_When_ValidUrl(value: "https://example.com")
✅ Create_Should_Succeed_When_ValidUrl(value: "HTTPS://EXAMPLE.COM")
✅ Equality_Should_Fail_For_DifferentValue
✅ Equality_Should_Work_For_SameValue
✅ ToString_Should_ReturnValue
✅ WebsiteErrors_Empty_Should_Have_Correct_Code_And_Description
✅ WebsiteErrors_Invalid_Should_Have_Correct_Code_And_Description

✅ EmptyDescription_Should_Have_Correct_Code_And_Description
✅ EmptyName_Should_Have_Correct_Code_And_Description
✅ NotFound_Should_Have_Correct_Code_And_Description

✅ Create_Should_ReturnError_When_DescriptionIsInvalid(invalidDescription: " ")
✅ Create_Should_ReturnError_When_DescriptionIsInvalid(invalidDescription: "")
✅ Create_Should_ReturnError_When_DescriptionIsInvalid(invalidDescription: null)
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: " ")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: "")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: null)
✅ Create_Should_ReturnMultipleErrors_When_MultipleFieldsInvalid
✅ Create_Should_SetCorrectProperties
✅ Update_Should_ChangeBoth_When_BothAreDifferent
✅ Update_Should_NotChange_When_ValuesAreSame
✅ Update_Should_OnlyModifyChangedProperties
✅ Update_Should_ReturnError_When_NameIsEmpty
✅ Update_Should_ReturnMultipleErrors_When_BothFieldsInvalid
✅ Update_Should_Succeed_When_AllFieldsNull

✅ DefaultProductId_Should_Have_Correct_Code_And_Description
✅ DefaultProductPriceTypeId_Should_Have_Correct_Code_And_Description
✅ EmptyCurrencyCode_Should_Have_Correct_Code_And_Description
✅ NegativePrice_Should_Have_Correct_Code_And_Description
✅ NotCreated_Should_Have_Correct_Code_And_Description
✅ NotFound_Should_Have_Correct_Code_And_Description

✅ Create_Should_Allow_ZeroPrice(zeroPrice: 0)
✅ Create_Should_ReturnError_When_CurrencyCodeIsInvalid(invalidCurrency: "   ")
✅ Create_Should_ReturnError_When_CurrencyCodeIsInvalid(invalidCurrency: "")
✅ Create_Should_ReturnError_When_PriceIsNegative(invalidPrice: -1)
✅ Create_Should_ReturnError_When_PriceIsNegative(invalidPrice: -100)
✅ Create_Should_ReturnError_When_ProductIdIsDefault
✅ Create_Should_ReturnError_When_ProductPriceTypeIdIsDefault
✅ Create_Should_ReturnMultipleErrors_When_MultipleFieldsInvalid
✅ Create_Should_SetCorrectProperties
✅ Update_Should_Change_SalePrice_And_CurrencyCode
✅ Update_Should_NotChange_When_ValuesAreSame
✅ Update_Should_ReturnError_When_SalePriceIsNegative
✅ Update_Should_Succeed_When_AllFieldsNull

✅ EmptyName_Should_Have_Correct_Code_And_Description
✅ NegativePriority_Should_Have_Correct_Code_And_Description
✅ NotCreated_Should_Have_Correct_Code_And_Description
✅ NotFound_Should_Have_Correct_Code_And_Description

✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: "   ")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: "")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: null)
✅ Create_Should_ReturnError_When_PriorityIsNegative(invalidPriority: -1)
✅ Create_Should_ReturnError_When_PriorityIsNegative(invalidPriority: -100)
✅ Create_Should_ReturnMultipleErrors_When_MultipleFieldsInvalid
✅ Create_Should_SetCorrectProperties
✅ Create_Should_Succeed_When_Valid
✅ ProductPriceTypeErrors_Should_Have_Correct_Values
✅ Update_Should_ModifyProperties
✅ Update_Should_NotChange_When_ValuesAreSame
✅ Update_Should_ReturnError_When_NameIsEmpty
✅ Update_Should_ReturnError_When_PriorityIsNegative
✅ Update_Should_Succeed_When_AllFieldsNull

✅ EmptyCategories_Should_Have_Correct_Code_And_Description
✅ EmptyDescription_Should_Have_Correct_Code_And_Description
✅ EmptyGTIN_Should_Have_Correct_Code_And_Description
✅ EmptyName_Should_Have_Correct_Code_And_Description
✅ EmptySKU_Should_Have_Correct_Code_And_Description
✅ NoBrand_Should_Have_Correct_Code_And_Description
✅ NoCategories_Should_Have_Correct_Code_And_Description
✅ NotCreated_Should_Have_Correct_Code_And_Description
✅ NotFound_Should_Have_Correct_Code_And_Description
✅ NullBrand_Should_Have_Correct_Code_And_Description

✅ Create_Should_Allow_Optional_GTIN(optionalGtin: "   ")
✅ Create_Should_Allow_Optional_GTIN(optionalGtin: "")
✅ Create_Should_Allow_Optional_GTIN(optionalGtin: null)
✅ Create_Should_GenerateValidSlug
✅ Create_Should_ReturnError_When_DescriptionIsInvalid(invalidDescription: "   ")
✅ Create_Should_ReturnError_When_DescriptionIsInvalid(invalidDescription: "")
✅ Create_Should_ReturnError_When_DescriptionIsInvalid(invalidDescription: null)
✅ Create_Should_ReturnError_When_DescriptionIsWhitespace
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: " ")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: "")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: null)
✅ Create_Should_ReturnError_When_SKUIsInvalid(invalidSku: "   ")
✅ Create_Should_ReturnError_When_SKUIsInvalid(invalidSku: "")
✅ Create_Should_ReturnError_When_SKUIsInvalid(invalidSku: null)
✅ Create_Should_ReturnError_When_SKUIsWhitespace
✅ Create_Should_ReturnMultipleErrors_When_MultipleFieldsInvalid
✅ Create_Should_SetCorrectProperties
✅ GetProductSlug_Should_ProduceExpectedSlug(input: "  ", expected: "")
✅ GetProductSlug_Should_ProduceExpectedSlug(input: "  My Product!  ", expected: "my-product")
✅ GetProductSlug_Should_ProduceExpectedSlug(input: "Product___Name", expected: "product-name")
✅ GetProductSlug_Should_ProduceExpectedSlug(input: "Product--Name", expected: "product-name")
✅ GetProductSlug_Should_ProduceExpectedSlug(input: "Product", expected: "product")
✅ Update_Should_DoNothing_When_NameIsNull
✅ Update_Should_DoNothing_When_NameIsSame
✅ Update_Should_OnlyModifyChangedProperties
✅ Update_Should_ReturnError_When_NameIsEmpty
✅ Update_Should_ReturnError_When_NameIsWhitespace
✅ Update_Should_ReturnMultipleErrors_When_NameIsNullOrWhitespace
✅ Update_Should_Succeed_When_NameIsNull

✅ EmptyName_Should_Have_Correct_Code_And_Description
✅ InvalidDateRange_Should_Have_Correct_Code_And_Description
✅ InvalidDiscount_Should_Have_Correct_Code_And_Description
✅ NoProducts_Should_Have_Correct_Code_And_Description

✅ Categories_Should_Initialize_As_EmptyCollection
✅ Create_Should_Allow_WhitespaceDescription
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: "   ")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: "")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: null)
✅ Create_Should_ReturnError_When_NameIsNull_Explicit
✅ Create_Should_ReturnError_When_ProductsContainNull
✅ Create_Should_ReturnError_When_ProductsIsEmpty
✅ Create_Should_ReturnError_When_ProductsIsNull
✅ Create_Should_ReturnError_When_ProductsIsNull_Explicit
✅ Create_Should_ReturnError_When_StartDateAfterEndDate
✅ Create_Should_ReturnMultipleErrors_When_MultipleFieldsInvalid
✅ Create_Should_ReturnMultipleErrors_When_MultipleFieldsInvalid_Explicit
✅ Create_Should_SetDescription_When_Provided
✅ Create_Should_SetDescriptionToEmptyString_When_EmptyStringProvided
✅ Create_Should_Succeed_When_DescriptionIsNull
✅ Create_Should_Succeed_When_Valid
✅ Create_Should_Succeed_With_SingleProduct
✅ Update_Should_Allow_EmptyProductsList
✅ Update_Should_ChangeProducts_When_ProductsProvided
✅ Update_Should_NotChange_When_AllFieldsAreSame
✅ Update_Should_NotChange_When_AllFieldsNull
✅ Update_Should_NotChange_When_CategoriesIsNotSet
✅ Update_Should_NotChange_When_DescriptionIsNull
✅ Update_Should_NotChange_When_DescriptionIsSame
✅ Update_Should_NotChange_When_ProductsIsNull
✅ Update_Should_NotChange_When_ValidFromIsSame
✅ Update_Should_NotChange_When_ValidToIsSame
✅ Update_Should_NotChange_When_ValuesAreSame
✅ Update_Should_NotChangeProducts_When_ProductsIsNull_And_OriginalIsEmpty
✅ Update_Should_OnlyModifyChangedProperties
✅ Update_Should_ReturnError_When_NameIsEmpty
✅ Update_Should_ReturnError_When_NameIsNullOrWhitespace
✅ Update_Should_ReturnError_When_NameIsWhitespace
✅ Update_Should_ReturnError_When_ValidToBeforeValidFrom
✅ Update_Should_ReturnError_When_ValidToBeforeValidFrom_BothProvided
✅ Update_Should_SetDescriptionToEmptyString_When_EmptyStringProvided
✅ Update_Should_SetDescriptionToNull_When_NullProvided
✅ Update_Should_SetProductsToEmpty_When_EmptyListProvided
✅ Update_Should_SetProductsToNull_When_NullProvided
✅ Update_Should_Succeed_When_AllFieldsNull
✅ Update_Should_UpdateAllFields_When_AllProvided
✅ Update_Should_UpdateValidFrom_Only
✅ Update_Should_UpdateValidTo_Only

✅ EmptyDescription_Should_Have_Correct_Code_And_Description
✅ EmptyName_Should_Have_Correct_Code_And_Description
✅ EmptyWebsite_Should_Have_Correct_Code_And_Description
✅ InvalidWebsite_Should_Have_Correct_Code_And_Description

✅ Create_Should_ReturnError_When_DescriptionIsEmpty(invalidDescription: "   ")
✅ Create_Should_ReturnError_When_DescriptionIsEmpty(invalidDescription: "")
✅ Create_Should_ReturnError_When_DescriptionIsWhitespace
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: "   ")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: "")
✅ Create_Should_ReturnError_When_NameIsInvalid(invalidName: null)
✅ Create_Should_ReturnError_When_NameIsWhitespace
✅ Create_Should_ReturnError_When_WebsiteIsInvalid(invalidWebsite: "   ")
✅ Create_Should_ReturnError_When_WebsiteIsInvalid(invalidWebsite: "")
✅ Create_Should_ReturnError_When_WebsiteIsInvalid(invalidWebsite: null)
✅ Create_Should_ReturnError_When_WebsiteIsMalformed(badWebsite: "ftp://badurl")
✅ Create_Should_ReturnError_When_WebsiteIsMalformed(badWebsite: "http:/missing-slash.com")
✅ Create_Should_ReturnError_When_WebsiteIsMalformed(badWebsite: "not-a-url")
✅ Create_Should_ReturnError_When_WebsiteIsNull
✅ Create_Should_ReturnError_When_WebsiteIsWhitespace
✅ Create_Should_ReturnMultipleErrors_When_AllFieldsInvalid
✅ Create_Should_ReturnMultipleErrors_When_MultipleFieldsInvalid
✅ Create_Should_SetCorrectProperties
✅ Create_Should_Succeed_When_DescriptionIsNull
✅ Create_Should_Succeed_With_Uppercase_Http_Or_Https
✅ Update_Should_ChangeDescription_When_NewValueProvided
✅ Update_Should_NotChange_When_DescriptionIsSame
✅ Update_Should_NotChange_When_ValuesAreSame
✅ Update_Should_NotChange_When_WebsiteIsSame
✅ Update_Should_OnlyModifyChangedProperties
✅ Update_Should_ReturnError_When_DescriptionIsEmpty
✅ Update_Should_ReturnError_When_NameIsEmpty
✅ Update_Should_ReturnError_When_WebsiteIsInvalid
✅ Update_Should_ReturnError_When_WebsiteIsMalformed
✅ Update_Should_ReturnError_When_WebsiteIsWhitespace
✅ Update_Should_ReturnMultipleErrors_When_MultipleFieldsInvalid
✅ Update_Should_SetWebsite_When_PreviouslyNull
✅ Update_Should_SetWebsite_When_ValidUrlProvided
✅ Update_Should_Succeed_When_AllFieldsNull
✅ Update_Should_UpdateAllFields_When_AllProvided