Many-to-Many Relationships

[ItsDoot]

Objective

• Closes Support Many-to-Many relationships #18121

Solution

• Relationships now have their own RelationshipCollection as well (previously named RelationshipSourceCollection).

Testing

Added additional unit tests.

---

Showcase

Many-to-many relationships are now supported:

#[derive(Component, PartialEq, Debug)]
#[relationship(relationship_target = LikedBy)]
struct Likes(pub Vec<Entity>);

#[derive(Component)]
#[relationship_target(relationship = Likes)]
struct LikedBy(Vec<Entity>);

[github-actions]

It looks like your PR is a breaking change, but you didn't provide a migration guide.

Please review the instructions for writing migration guides, then expand or revise the content in the migration guides directory to reflect your changes.

[github-actions]

Your PR caused a change in the graphical output of an example or rendering test. This might be intentional, but it could also mean that something broke!
You can review it at https://pixel-eagle.com/project/B04F67C0-C054-4A6F-92EC-F599FEC2FD1D?filter=PR-18657

If it's expected, please add the M-Deliberate-Rendering-Change label.

If this change seems unrelated to your PR, you can consider updating your PR to target the latest main branch, either by rebasing or merging main into it.

[github-actions]

Your PR caused a change in the graphical output of an example or rendering test. This might be intentional, but it could also mean that something broke!
You can review it at https://pixel-eagle.com/project/B04F67C0-C054-4A6F-92EC-F599FEC2FD1D?filter=PR-18657

If it's expected, please add the M-Deliberate-Rendering-Change label.

If this change seems unrelated to your PR, you can consider updating your PR to target the latest main branch, either by rebasing or merging main into it.

[github-actions]

Your PR caused a change in the graphical output of an example or rendering test. This might be intentional, but it could also mean that something broke!
You can review it at https://pixel-eagle.com/project/B04F67C0-C054-4A6F-92EC-F599FEC2FD1D?filter=PR-18657

If it's expected, please add the M-Deliberate-Rendering-Change label.

If this change seems unrelated to your PR, you can consider updating your PR to target the latest main branch, either by rebasing or merging main into it.

[homebrewmellow]

I'm praying for you brother

[hukasu]

do you have an example of how insertion and deletions will work?
insertion and deletion of items on the Vecs, not the Component