Preset: near-operation-file `extractAllFieldsToTypes` handling of nested interfaces in type names

[Georgegriff]

Which packages are impacted by your issue?

@graphql-codegen/typescript-operations

Describe the bug

I've been trying to workthrough the hell that is migrating off the apollo codegen, we can get most of the way there with near-operation-file adjusting some imports and using extractAllFieldsToTypes but i think i've found a bug with extractAllFieldsToTypes and how it handles nested interfaces - types that have the same fields present.

I've created a reproduction repo: https://github.com/Georgegriff/graphql-codegen-repro/tree/main

Example query

export const GET_ANIMALS = gql`
  query GetAnimals {
    animals {
      name
      age
      species
      owner {
        name
        license
      }
    }
  }

In this example animal has two types a Cat and Dog (same fields) and Owner has two types Trainer & Veterinarian also with the same fields present.

I am deliberately not using .. on inline fragments to show the issue.

The types generated end up like this

export type GetAnimals_animals_Cat_owner_Trainer = { __typename: 'Trainer', name: string, license: string };

export type GetAnimals_animals_Cat_owner_Veterinarian = { __typename: 'Veterinarian', name: string, license: string };

export type GetAnimals_animals_Cat_owner = GetAnimals_animals_Cat_owner_Trainer | GetAnimals_animals_Cat_owner_Veterinarian;

export type GetAnimals_animals_Cat = { __typename: 'Cat', name: string, age: number, species: string, owner: GetAnimals_animals_Cat_owner };

export type GetAnimals_animals_Dog = { __typename: 'Dog', name: string, age: number, species: string, owner: GetAnimals_animals_Cat_owner };

export type GetAnimals_animals = GetAnimals_animals_Cat | GetAnimals_animals_Dog;

export type GetAnimals_Query = { animals: Array<GetAnimals_animals> | null };

See how GetAnimals_animals_Dog owner field is GetAnimals_animals_Cat_owner this is strange because that type is not specific to Cats its a general owner type that is common between the two.

I wonder if in this case the Interface name should be used in the typename? or no typename at all, i'm not sure.

Your Example Website or App

https://github.com/Georgegriff/graphql-codegen-repro

Steps to Reproduce the Bug or Issue

I've created a reproduction repo: https://github.com/Georgegriff/graphql-codegen-repro/tree/main

Expected behavior

The common types generated don't use one of the child types in their name

Screenshots or Videos

No response

Platform

-OS: macOs

• NodeJS: [22
• graphql version: [e.g. 16.3.0]
• @graphql-codegen/* version(s):
• "@graphql-codegen/cli": "^6.0.2",
  "@graphql-codegen/near-operation-file-preset": "^3.1.0",
  "@graphql-codegen/typescript": "^4.0.1",
  "@graphql-codegen/typescript-operations": "^4.0.1"

Codegen Config File

import type { CodegenConfig } from "@graphql-codegen/cli";

const config: CodegenConfig = {
  schema: "schema.json",
  documents: ["query.ts"],
  config: {
    preResolveTypes: true,
    namingConvention: "keep",
    avoidOptionals: {
      field: true,
    },
    nonOptionalTypename: true,
    skipTypeNameForRoot: true,
    extractAllFieldsToTypes: true,
    skipDocumentsValidation: {
      skipValidationAgainstSchema: true,
      ignoreRules: true,
      skipDuplicateValidation: true,
    },
    omitOperationSuffix: true,
  },
  generates: {
    "types/graphql-global-types.ts": {
      plugins: ["typescript"],
    },
    "types/": {
      preset: "near-operation-file",
      presetConfig: {
        baseTypesPath: "graphql-global-types.ts",
        folder: "./types",
      },
      plugins: ["typescript-operations"],
    },
  },
};

export default config;

Additional context

The issue is likely in packages/plugins/other/visitor-plugin-common/src/selection-set-to-object.ts but i can't see a clean fix, especially not one that might change generated types

[Georgegriff]

A possible fix https://github.com/dotansimha/graphql-code-generator/pull/10503/files

My thinking is if we're not using fragments, and the parent is an interface they we should use the parents type name for the common type object not one of the merged children?

[eddeee888]

Hi @Georgegriff , thank you! I'll have a look at the PR soon

We are working on the next major for client use case here: #10479

extractAllFieldsToTypes is part of the work that we are doing.
I'll include this issue in that issue tracking (maybe this can be done before the major version, I'll have a think).

[Georgegriff]

@eddeee888 Hey, have you had any time to think about this yet?

[eddeee888]

Hi @Georgegriff !
Thanks for that PR, it looks very reasonable! Let me run CI on it.

[Georgegriff]

Thanks, I just took it out of draft