Incorrect graphql validation

[MaximusMcCann]

Compared to GraphiQL

fragment _Pie on Pie {
  __typename
  id
  ... on SystemPie {
    isActive
  }
}

[MaximusMcCann]

SystemPie and UserPie are of the interface type Pie.

The above also works in our current implementation.

[martijnwalraven]

@MaximusMcCann: Could you include the relevant part of your schema?

apollo-codegen uses graphql-js for validation, so the results should be the same as GraphiQL. Validation rules may have changed depending on graphql-js versions however.

When you say this works in your current implementation, what setup are you describing?

[MaximusMcCann]

The parser is incorrectly evaluating the SystemPie to a UserPie here.

Works in the sense that graphiql has no issues with determining the SystemPie has the isActive flag. We also query this in production and the isActive flag is returned when the item is a SystemPie.

Pie = Interface
UserPie implements Pie
SystemPie implements Pie

Unfortunately, cannot copy and paste a schema portion atm.

[martijnwalraven]

I'm not sure what could be going on here, and without something reproducible (like part of a schema) it is difficult to investigate further.

apollo-codegen 0.9 updates graphql-js to the most recent version, so that might solve your issue. Could you give that a try and report back?