Field Paths

[magicmark]

Response Position is defined in the spec to refer a position in the response.

Do we / should we have something to refer to a position in ExecutableDefinition (i.e. an operation or fragment)?

The proposed syntax is:

Example

fragment FooFields on Foo {
  bar # field path is `bar`

  aliasedBar: bar # field path is `aliasedBar`

  baz {
    qux # field path is `baz.qux`
  }
}

(array indicators are not part of a Field Path since this information isn't encoded in an operation/fragment definition)

I suspect this might already be used in some places? Curious if anyone has prior art in existing tooling that might uncover any edge cases.

Motivation

Being able to refer a "field path" (without having to first define what a "field path" is would be useful in graphql/gaps#10: (https://github.com/graphql/gaps/pull/10/changes#r2986114701)

Additionally, I could maybe see this being useful in linter tools and such?

[magicmark]

There is an interesting edge case which is that this is a valid document

query {
  fooOrBar {
    qux
    ... on Foo {
      qux
    }
    ... on Bar {
      qux
    }
  }
}

and then there's 3 possible nodes that could be mapped to for fooOrBar.qux 🤔

It would be a nice property to have a 1-1 mapping.

To complicate things, we could encode type conditions and do something like:

• fooOrBar.qux
• fooOrBar[Foo].qux
• fooOrBar[Bar].qux

[benjie]

This might be similar to operation expressions: https://github.com/graphql/graphql-wg/blob/main/rfcs/OperationExpressions.md