Add graphql codegen to starwars example

[wKich]

Motivation

GraphQL Yoga example doesn't have codegen config

Approach

Add simple codegen config and use generated types in GraphQL resolvers

Possible Drawbacks or Risks

The example is pretty simple, so it doesn't show potential issues with generated types

[taras]

@cowboyd @wKich This current setup just makes typescript not complain but it doesn't help people writing the resolvers. Is there a better way to type this so we can actually use TypeScript for guidance in parameters?

[wKich]

Yeah, you are right. It's better to declare resolvers:

const resolvers: Resolvers = { /* ... */ }

[cowboyd]

Another option is to wrap createModule() to require the type of resolvers to be Resolvers. Another pattern I've become fond of is to use a function:

function moduleResolvers(): Resolvers {
}

and then invoke it like:

createModule({
  id: "starwars",
  dirname: import.meta.url,
  resolvers: moduleResolvers(),
});

Or as something that can be spread in:

function moduleResolvers(): { resolvers: Resolvers } {
 //....
}

createModule({
  id: "starwars",
  dirname: import.meta.url,
  ...moduleResolvers(),
});

[taras]

I'm happy with the ...moduleResolvers() or moduleResolves() - both work fine.