Analyzer diagnostics

Mapperly emits several diagnostics:

Rule ID	Severity	Description
RMG001	Error	A mapping method has an unsupported signature.
RMG002	Error	No accessible parameterless constructor found.
RMG003	Warning	No overlapping enum members found.
RMG004	Warning	Ignored target property not found.
RMG005	Error	Mapping target property not found.
RMG006	Error	Mapping source property not found.
RMG007	Error	Could not map property.
RMG008	Error	Could not create mapping.
RMG009	Info	Cannot map to read only property.
RMG010	Info	Cannot map from write only property.
RMG011	Info	Cannot map to write only property path.
RMG012	Info	Mapping source property not found.
RMG013	Error	No accessible constructor with mappable arguments found
RMG014	Warning	Cannot map to the configured constructor to be used by Mapperly
RMG015	Info	Cannot map to init only property path
RMG016	Error	Init only property cannot handle target paths
RMG017	Warning	An init only property can have one configuration at max
RMG018	Error	Partial static mapping method in an instance mapper
RMG019	Error	Partial instance mapping method in a static mapper
RMG020	Info	Source property is not mapped to any target property
RMG021	Warning	Ignored source property not found
RMG022	Error	Invalid object factory signature
RMG023	Error	Mapping source property for a required target property not found
RMG024	Error	The reference handler parameter is not of the correct type
RMG025	Error	To use reference handling it needs to be enabled on the mapper attribute
RMG026	Info	Cannot map from indexed property
RMG027	Warning	A constructor parameter can have one configuration at max
RMG028	Error	Constructor parameter cannot handle target paths

info

Mapperly only emits updated source code on build. You won't see the updated mapper code or mapper diagnostics until you perform a build.

This is done for performance reasons, otherwise the IDE could become laggy. Improvements are tracked in #72.

Editorconfig

The severity of these diagnostics can be customized via an .editorconfig file:

.editorconfig

dotnet_diagnostic.{RuleID}.severity = error
dotnet_diagnostic.RMG020.severity = error

Strict mappings

To enforce strict mappings (all source properties have to be mapped to a target property and all target properties have to be mapped from a source property) set the following two editorconfig settings:

.editorconfig

dotnet_diagnostic.RMG012.severity = error # Unmapped target property
dotnet_diagnostic.RMG020.severity = error # Unmapped source property