[IIncrementalGenerator] Multiple files same symbol

[workgroupengineering]

Structure

considering following project structure:

MyProject 
│
├ MyNamespace ┬ MyObject.cs
│             ├ MyObject.Do.cs
│             ├ MyObject.Properties.cs 
┋             ┋

MyObject.*.cs is same symbol, but it is split into more files for better readability.

Use case

I'm trying to create an incremental generator that generates a code when the symbol has an attribute that implements a specific interface.
To do this, I created CreateSyntaxProvider which filters all ClassDeclarationSyntax nodes and in the transformation function obtains the symbol via syntaxContext.SemanticModel.GetDeclaredSymbol(syntaxContext.Node, token) and checks that it has an attribute that implements a specific interface

The Issue

From the tests I have done, I see that the generator is invoked for each file that makes up the symbol, creating duplicate code.
How can I avoid this problem?

[CyrusNajmabadi]

You'll need your incremental generator pipeline to .Collect all the elements and process them in aggregate to know what to merge and what to filter or throw out.

Note:

I'm trying to create an incremental generator that generates a code when the symbol has an attribute

You should use .ForAttributeWithMetadataName for this purpose. It's normally around 100x faster and uses around 100x memory to accomplish the same task. As a bonus, it is symbol (not syntax) based. So you'd only get this symbol a single time, even though it has multiple parts spread across multiple files.