Help building codegen plugin to replace our usage of apollo client:codegen

[sawilde]

Hi all, we've made extensive use of apollo client:codegen to generate our types that migrating them to using the types generated by graphql-codegen was just too much manual work

I've managed to create a rudimentary spike that shows that what I want to do is feasible(ish) ie

we used to generate

export type UpdateThing_updateThing = ...;

export interface UpdateThing {
  updateThing: UpdateThing_updateThing;
}

but using the typescript + typescript-operations plugins (and the near-operation-file preset) + our codegen plugin we get

import { UpdateThingMutation } from "../mutations.generated";

export interface UpdateThing extends UpdateThingMutation {};

and all is well (ie nothing sulks).

But I am finding testing it against our codebase quite difficult as I keep getting this error when I use yarn link to connect the development space of the plugin to the node_modules of our main application (from where I execute the codegen against some real code and not just tests)

Cannot use GraphQLNonNull "CreateXYZResponse!" from another module or realm.
      Ensure that there is only one instance of "graphql" in the node_modules
      directory. If different versions of "graphql" are the dependencies of other
      relied on modules, use "resolutions" to ensure only one version is installed.
      https://yarnpkg.com/en/docs/selective-version-resolutions
      Duplicate "graphql" modules cannot be used at the same time since different
      versions may have different capabilities and behavior. The data from one
      version used in the function from another could produce confusing and
      spurious results.

I've checked that I only have one flavour of graphql in either repository and it is the same. Any hints or tips on how I can dev/debug this issue?

I am using the workaround as mentioned here but is a bit laborious and I wondered if the advice has since changed
#5779

[sawilde]

I've had another thought over this, whilst cooking, and now have a better way of working that gives me the faster turnaround I am after; I still feel there should be a better way though.

1. create a dev tsconfig.json to output the build to my mainproject folder

{
  "extends": "@tsconfig/recommended/tsconfig.json",
  "compilerOptions": {
    "outDir": "../../../mainproject/apollo-codegen"
  },
  ...
}

2. reference the output folder in the codegen config file rather than my package from node_modules

{
   ...
   preset: 'near-operation-file',
   ...
   plugins: [
        {
        'typescript-operations',
        // '@myorg/graphql-codegen-apollo-operations',
        'apollo-codegen',
      ],
  ...
}

I hope this makes sense...