Microsoft.VisualStudio.Composition.Analyzers

Analyzers for MEF consumers to help identify common errors in MEF parts.

Analyzer ID	Description
VSMEF001	Ensures that importing properties define a set accessor.
VSMEF002	Detects mixing of MEF v1 and MEF v2 attributes on the same type.
VSMEF003	Ensures that exported types are implemented by the exporting class.
VSMEF004	Ensures exported types have a parameterless constructor or importing constructor.
VSMEF005	Detects multiple constructors marked with [ImportingConstructor].
VSMEF006	Ensures import nullability matches AllowDefault setting.
VSMEF007	Detects when a type imports the same contract multiple times.
VSMEF008	Warns when an import contract type is not assignable to the importing member type.
VSMEF009	Ensures [ImportMany] members use supported collection shapes and can be initialized correctly.
VSMEF010	Ensures constructor-parameter [ImportMany] imports use supported collection types.
VSMEF011	Detects members annotated with both [Import] and [ImportMany].
VSMEF012	Warns when a disallowed MEF attribute version is used.
VSMEF015	Warns when a same-compilation metadata view interface could be source-generated but is not annotated for generation.
VSMEF016	Warns when a referenced metadata view interface should be recompiled with [MetadataView].
VSMEF017	Reports invalid [MetadataView] usage on interfaces that cannot be source-generated.

Diagnostic Suppressors

Suppressor ID	Suppressed Diagnostic	Description
VSMEF013	IDE0044	Suppresses "Make field readonly" for fields decorated with MEF [Import] or [ImportMany] attributes, since such fields are assigned at runtime via reflection.
VSMEF014	CS8618	Suppresses "Non-nullable member must contain a non-null value when exiting constructor" for MEF importing members that are initialized after construction unless AllowDefault = true is specified.
VSMEF018	CS0649	Suppresses "Field is never assigned to, and will always have its default value" for MEF imported fields on exported parts, since composition assigns them at runtime.