Analyzer Rules

Vogen emits the following diagnostics. Errors (VOGxxx) prevent code generation; warnings advise on configuration that has no effect.

ID	Severity	Description
VOG001	Error	Types cannot be nested
VOG002	Error	Underlying type must not be the same as the value object
VOG003	Error	Underlying type cannot be a collection
VOG004	Error	Validation method must return `Validation`
VOG005	Error	Validate method must be static
VOG006	Error	Instance method cannot have a null argument name
VOG007	Error	Instance method cannot have a null argument value
VOG008	Error	Cannot have user-defined constructors
VOG009	Error	Do not use `default` to create a value object
VOG010	Error	Do not use `new` to create a value object
VOG011	Error	Invalid `Conversions` combination
VOG012	Error	Custom exception must derive from `System.Exception`
VOG013	Error	Custom exception must have a valid constructor
VOG014	Error	NormalizeInput method must be static
VOG015	Error	NormalizeInput method must return the same underlying type
VOG016	Error	NormalizeInput method must take one parameter of the underlying type
VOG017	Error	Types cannot be abstract
VOG019	Error	Invalid `Customizations` combination
VOG020	Error	`ToString` override on a record should be sealed
VOG021	Error	Value object type should be partial
VOG022	Error	Invalid `DeserializationStrictness` combination
VOG023	Error	Instance value cannot be converted to the underlying type
VOG024	Error	Duplicate value object types found
VOG025	Error	Do not use reflection to create a value object
VOG026	Error	Do not derive from Vogen attributes
VOG027	Error	Incorrect use of an instance field
VOG028	Error	Incorrect use of a NormalizeInput method
VOG029	Error	Type must explicitly specify the underlying type in the `ValueObject` attribute
VOG031	Error	Types referenced in a conversion marker must be value objects
VOG032	Error	Do not throw from user validation or normalization code
VOG033	Warning	Prefer `readonly struct` instead of `struct`
VOG034	Warning	Do not compare with primitives in EF Core queries
VOG035	Error	Value object referenced in a conversion marker must explicitly specify its primitive type
VOG036	Error	Both implicit and explicit casts specified
VOG037	Warning	`NumericsGeneration.Generate` has no effect because the underlying type does not implement `INumberBase<T>`

Last modified: 11 May 2026