amplify-codegen add a way to config GraphQL Codegen

Is this related to a new or existing framework?

No response

Is this related to a new or existing API?

No response

Is this related to another service?

No response

Describe the feature you'd like to request

I want to remove __typename from the api.ts, with the raw GraphQL Codegen, I could config this by the skipTypename option, but how to config this in Amplify CLI ?

Additional context

No response

Is this something that you'd be interested in working on?

[ ] 👋 I may be able to implement this feature request
[ ] ⚠️ This feature might incur a breaking change

May 24 '21 11:05 yaquawa

Hi @yaquawa :wave:, thanks for raising. I'm going to transfer to the Codegen repo to get some more eyes on it.

May 24 '21 14:05 siegerts

Hi @yaquawa. The __typename is a meta field provided by GraphQL server [refer]. Unfortunately there is not way you can omit generating it currently. What is your use-case for omitting it? Can you work around it by ignoring that field?

Jun 02 '21 18:06 phani-srikar

@phani-srikar I use the generated types fo DTO objects, but the generated type mark the __typename as a required field, which is not true in DTO objects because the __typename field will be auto generated even if you don't give a value to it.

Jun 03 '21 10:06 yaquawa

To hook into this discussion: the generated types are also all nullable for optional properties, which means that every single connection (for example) could be null, or an array of nulls (lol).

This makes the generated types practically useless in a front-end, because you have to either start casting things to the "real" types or add all kinds of condition checks that never should exist anyway.

To illustrate: a query for Assets:

export type ListAssetsQuery = {
  listAssets?:  {
    __typename: "ModelAssetsConnection",
    items?:  Array< {
      __typename: "Asset",
      id: string,
      createdAt: string,
      updatedAt: string,
    } | null > | null,
    nextToken?: string | null,
  } | null,
};

Questions I have about this:

Why is listAssets optional, it's the point of the query?
Why is items optional, it's an array at all times
Why is items possibly an array of nulls?
Why is items possibly null? It should just be an empty array if there's no data

All of this leads to incredibly (and overly) difficult FE implementation and there's no way around it, except for manually creating types (which defeats the whole point of generating them).

To further illustrate my point, here's a quick example of how improper these types are: https://www.typescriptlang.org/play?#code/C4TwDgpgBAYg9nKBeKBvAUFKAzBB+ALigEEAnUgQxAB4BnYUgSwDsBzAPgG50BfddUJCgAhCqWRpMUAEZjCJclToMWrKAB8ozAK4AbXew1a9u7n3QBjOM3o4AjEXiIUGLLjhEd+gDS9+Vm2AcACZHBAlXHAQiAG0AXV9zANtsAGYw50k3aKgYr10Ev0trFIAWDIipd1iAcncawqSSoOkHETFKrFlSTxNE-2aZUPbxFylu2MaBwJl0kc6ZMVj8qeKZ6XL5sa6l3JrdOF0GxKA

Optional properties shouldn't be nullable, they're either there or not and it leads to a whole host of nested problems, including strange arrays of nulls being possible.

Aug 31 '21 00:08 TheDutchCoder

@TheDutchCoder Thanks for putting this out. It looks like a bug for the type generation of graphql operations. I will look into this and make a fix soon