Propose to make node data NOT optional

The current data type for Node is

This means even when you assign T such as Node<ElementData> and know in your program all Nodes would have T. it will still show the data as possibly being undefined.

Because T defaults to any which could be undefined.

Changing data?: T to data: T would still allow setting data: undefined on new element objects if needed.

Side note, I think the default renderer for nodes actually requires the data to be { label: 'string } so setting undefined on Nodes might crash application which means this is another reason it should not be typed as optional since it’s actually required.

[moklick]

Good point. I think we should make data of an Edge non-optional, too.

[tisoap]

@moklick On a project I faced an issue where nodes needed to have a certain data shape, but even if the external interface to my component consuming React Flow did make it required, I still had to do type casting since <ReactFlow> callbacks assume data is optional, even if I’m enforcing it to not be from the outside