[typescript] Why is parent/args hardcoded as optional?

Hi there, awesome project to make server-side graphql even more enjoyable.

I just generated some typescript typings

gql-gen --schema ./schema.js --template graphql-codegen-typescript-template --out ./typings/

It generated typings/types.ts as expected:

...
export type Resolver<Result, Parent = any, Context = any, Args = any> = (
  parent?: Parent,
  args?: Args,
  context?: Context,
  info?: GraphQLResolveInfo
) => Promise<Result> | Result;
...

“parent” and “args” are optional, this is hardcoded in:

https://github.com/dotansimha/graphql-code-generator/blob/master/packages/templates/typescript/src/schema.handlebars#L5-L7

AFAIK the “parent” field is only optional for root types Query/Mutation/Subscription.

The “args” field should only be optional if the corresponding graphql field arguments are optional.

Am I doing something wrong?

[kamilkisiela]

@dotansimha @ardatan @jzimmek

[kamilkisiela]

I would make them non optional, because in most cases they are. This will hurt a bit while unit testing:

fooResolver({} as any, {}, context, {} as any)

But.

You can always wrap resolvers with this function in unit tests:

type MockResolver<Result, Args> = (
  parent?: any,
  args?: Args,
  context?: any,
  info?: any
) => Promise<Result> | Result;

export function mockResolver<R, A>(
  resolver: Resolver<R, A>
): MockResolver<R, A> {
  return (parent, args, context, info) => resolver(parent, args, context, info);
}

This will make all arguments optional and TS, that weird mad beast, won’t scream