SetValue is not invoked in a Dapper custom TypeHandler

[oS-So]

As per THIS question:

Given:

public class GuidHandler : SqlMapper.TypeHandler<Guid>
{
 public override void SetValue(IDbDataParameter parameter, Guid value)
 {
 // My Custom logic
 }

 public override Guid Parse(object value)
 {
 return Guid.Parse(value.ToString());
 }
}
...
SqlMapper.AddTypeHandler(new GuidHandler());

Even though the Parse is correctly invoked when reading from the DB, the SetValue however never gets called when writing the data.

Any idea of what is going on?

[chilversc]

Dapper doesn't support custom type handlers for in-built primitive types at the moment, see #303 #206 and #458

[kwaclaw]

Seems this issue has fallen off the radar. Is there a workaround?

[chilversc]

Not at the moment, the main reason is it could be a breaking change for existing code as the simple solution is to move the check for ITypeHandler earlier in the code.

Another solution would be to have 2 functions to register a type handler, a "late" function (the current one) and an "early" function. The issue with that is it makes the API confusing as you have to explain the difference.

[kwaclaw]

I guess one could add a configuration item like "UseLegacyTypeHandling" which is turned on by default to maintain backwards compatibility.

[andrey-perepelitsyn]

This bug has been living for 6 years so far. 6 years of broken type mapping, just not to break compatibility.
Are there any plans to fix it? Maybe workarounds?