How to create a custom package with optional extensions/modules?

We have a tooling package with some optional extensions/modules.

Like:

<root>

├── package.json

├── README.md

├── CHANGELOG.md

├── LICENSE.md

├── Editor

│   ├── Unity.[YourPackageName].Editor.asmdef

│   └── EditorExample.cs

├── Runtime

│   ├── Unity.[YourPackageName].asmdef

│   └── RuntimeExample.cs

├── Tests

│   ├── Editor

│   │   ├── Unity.[YourPackageName].Editor.Tests.asmdef

│   │   └── EditorExampleTest.cs

│   └── Runtime

├── Demos // This needs to be optional

│   ├── Example 1 

│   └── Example 2

├── Extensions

│   ├── Option 1  // This needs to be optional

│   └── Option 2 // This needs to be optional

│     

├── Unity.[YourPackageName].Tests.asmdef

│        └── RuntimeExampleTest.cs

└── Documentation~

└── [YourPackageName].md

Is there a way to flag a folder as a module? So you the user can be prompted to add that folder for installation. Or do we have to create an extra package - for the particular extension - and add a dependency?

The same goes for Demos. In the Unite's Copenhagen talk there's an example of using a .sample.jason manifest.

Are there any best practices to this?

 

For demos there's this approach: https://forum.unity.com/threads/samples-in-packages-manual-setup.623080/

Is there something available for modules/extensions too?

 

separate packages is the cleanest way (you can add a script to the main package that manages the sub-packages and adds them to the project using UPM API)

that way you can add more extensions without being forced to upgrade the main package

 

Thank you for your response,
Yes I was thinking the same, about the approach you mentioned. Thus separate packages with dependencies to the main package. Or the other way. Will investigate it further.

 

If optional module has a another package as dependency we can use AssemblyDefenition.VersionDefines for this https://docs.unity3d.com/Manual/ScriptCompilationAssemblyDefinitionFiles.html#define-symbols