Federation: requiring a field with a list of objects generates invalid code

[arnemolland]

What happened?

When extending a federated entity with a field of the array type containing object (not primitives/scalars) and adding a field that requires the array field, gqlgen generate generates invalid code. It looks like the execution context does not have any unmarshaler for the specific type. I'm not sure if this kind of relation is valid in GraphQL or if it's missing in gqlgen.

What did you expect?

When extending a federated entity with a field of the array type containing object (not primitives/scalars) and adding a field that requires the array field, gqlgen generate generates valid code.

Minimal graphql.schema and models to reproduce

type Bar {
  id: Int!
}

extend type Foo @key(fields: "id") {
  id: Int!
  arr: [Bar!]! @external
  xyz: Int! @requires(fields: "arr")
}

Logs

gofmt failed on federation.go: /Users/arne/dev/orgs/gameflow/backend/graph-template-go/graph/generated/federation.go:105:33: expected ')', found ',' (and 1 more errors)
validation failed: packages.Load: /Users/arne/dev/orgs/gameflow/backend/graph-template-go/graph/generated/federation.go:105:33: expected ')', found ','
/Users/arne/dev/orgs/gameflow/backend/graph-template-go/graph/generated/federation.go:105:35: expected ';', found rep
/Users/arne/dev/orgs/gameflow/backend/graph-template-go/graph/generated/federation.go:105:26: invalid operation: ec (variable of type *executionContext) is not an interface

Invalid code

entity.Arr, err = ec.(ctx, rep["arr"])

versions

• gqlgen version? v0.14.0-dev
• go version? go version go1.17.6 darwin/arm64
• dep or go modules ? modules

[bpteam]

Still actual for versions

• gqlgen version? v0.17.2
• go version? go version go1.17.6 darwin/arm64

[dariuszkuc]

fixed in #2884