Resolvers: Add a way to export/import resolvers while preserving type safety

[matthew-salerno]

Description

First mention in #3132. My resolvers are getting quite large. I would to split them out of my openapi-ts.config.ts file. However, I cannot do this without losing type safety:

// Not type checked anymore!
// Type was: (ctx: NumberResolverContext$1) => PipeResult | undefined
// Type is now: (ctx: any) => any
export const myNumberResolver = function number(ctx) {
  ...
}

I would like to be able to provide type info like I can for transformers:

// Nice and easy, I get to reuse TypeTransformer
// Still type checked for correctness
export const myTransformer: TypeTransformer = ({ schema }) => {
  ...
}

This can be marked enhancement, I wanted to be able to link the stackblitz reproducer but couldn't when I used the enhancement template.

Reproducible example or configuration

https://stackblitz.com/edit/ttamttam-heyapi-resolver-imports

OpenAPI specification (optional)

No response

System information (optional)

No response

[bolt-new-by-stackblitz]

Start a new pull request in StackBlitz Codeflow.

• ttamttam-heyapi-resolver-imports (Open reproduction)