Feature Request/Unexpected behaviour: Graphql handlers just return string ids instead of relationships

[mswjs]

Feature Request/Unexpected behaviour: Graphql handlers just return string ids instead of relationships

[phryneas]

I don't really have the time for that as I have tons of open issues to work on myself :/

But if I find one or two hours I'll dig into the code - maybe it's less work than I'm imagining.

But otherwise, if someone else sees this issue and thinks "Hey, I can do this" - take it! :D

I don't really need this right now (although it would be nice in our examples), I just noticed it and wanted to put it here as a suggestion for the roadmap - with whichever priority you give it in the end :)

[kettanaito]

Hey, @phryneas. You're right, the current GraphQL type of a relation would be reduced to a primitive, which doesn't produce a valid GraphQL schema in the end:

factory({
  user: {
    post: oneOf('post')
  },
  post: { ... }
})

type User {
-  post: String
+  post: Post
}

I can't say from the top of my head if the schema generation logic can determine a value being a relational node to infer its type, or we'd have to extend the logic to have access to relational nodes.

Please, would you be interested in tackling this? I'd be happy to help with code reviews in the process.

[kettanaito]

Since a model may reference other models (relational properties), it's no longer possible to generate a complete GraphQL schema from a single given model (it may depend on other models).

In other words, given a factory like this:

const db = factory({
  user: {
    id: primaryKey(datatype.uuid),
    role: oneOf('role'),
  },
  role: {
    id: primaryKey(datatype.uuid),
    name: String,
  },
})

Generating the GraphQL types via db.user.toGraphQLSchema() become a no-op in the current implementation, as in order to type the role field of the User type the library needs to generate the Role type of an unrelated model definition.

As I've suggested above, it looks like the library needs to have access to the entire dictionary to generate a complete GraphQL schema for any given model. At first, I thought about optimizing the generation process by analyzing model dependencies a single dependency has (what models it references, like user above references the role model), but I came to realize that'd be a bad idea. Models may depend on other models, and now we're compiling a model dependency tree and it's likely to be a mess that results in the entire dictionary being converted into a GraphQL schema anyway.

To summarize, it looks like this change implies the internal change:

-generateGraphQLSchema(model): GraphQLSchema
# We'd have to expose the dictionary and generate GraphQL types for all models.
+generateGraphQLSchema(model, dictionary): GraphQLSchema