Update ... Delete operation fails for unions

[angrykoala]

Given the following typedefs:

type Movie @node {
    title: String!
    actors: [Actor!]! @relationship(type: "ACTED_IN", direction: IN)
}

type LeadActor @node {
    name: String!
    actedIn: [Movie!]! @relationship(type: "ACTED_IN", direction: OUT)
}

type Extra @node {
    name: String
    actedIn: [Movie!]! @relationship(type: "ACTED_IN", direction: OUT)
}

union Actor = LeadActor | Extra

The following query:

mutation UpdateMovies {
  updateMovies(
    update: {
      actors: {
        LeadActor: [{ delete: [{ where: { node: { name: "Actor1" } } }] }]
      }
    }
  ) {
    movies {
      title
    }
  }
}

Should delete all LeadActors named "Actor1" connected to a move. However, it fails with the following error:

"Cannot read properties of undefined (reading 'name')"

This seems to be an issue with unions, as the equivalent query with concrete types does not fail

[neo4j-team-graphql]

We've been able to confirm this bug using the steps to reproduce that you provided - many thanks @angrykoala! 🙏 We will now prioritise the bug and address it appropriately.