feat: add default resolver for relation fields

[lvauvillier]

This is a proposal for default resolver generation:

A new resolvefield is generated in models:

objectType({
  name: User.$name,
  definition(t) {
    t.field(User.posts.name, {
      type: User.posts.type
      resolve: User.posts.resolve
    });
  }
});

or

objectType({
  name: User.$name,
  definition(t) {
    t.field(User.posts.name, User.posts);
  }
});

Need guidance

Current implementation expect to find a prisma instance in context.prisma.
How can we make it configurable?

The old spec (https://gist.github.com/jasonkuhrt/fb5dcb58ba9bf68123460138cb17bc40) suggest to create a new instance and share a singleton across all models, but this is not ideal as a new instance will create a new connexion pool to the db.

Tests are currently broken... I'm waiting for a resolution to start adding tests for this PR

Todo

• Export default resolver
• Customize prisma instance location in context
• Add tests

[jasonkuhrt]

In your example:

t.field(User.posts.name, Model.posts);

I think you meant User.posts?

---

How can we make it configurable?

Let's start by making it not configurable. It is, in many cases, not hard for a developer to add Prisma client to another property on context.

I want features to be shipping in very small increments right now.

I suggest we hardcode looking for .prisma on the context.

---

Later I think we can also consider some singleton settings system.

import { $settings } from 'nexus-prisma'

$settings({
  client: // user passes reference to prisma client instance here
})

Alt API:

import { $set } from 'nexus-prisma'

$set.client = // setter, user passes reference to prisma client instance here

[jasonkuhrt]

Dropped some feedback, didn't have time to go deep on the heart of the implementation, just superficial pass.

[jasonkuhrt]

In my spec about relation resolvers https://gist.github.com/jasonkuhrt/fb5dcb58ba9bf68123460138cb17bc40#relationship-resolver I had imagined trying to use findMany with where as a general solution for all cases.

I'm ok shipping another solution for now if you're doing it, but just wanted to point this out at least.

The thing is, findUnique will not account for all relation cases.

But findMany with where could.

I realize findUnique might be more optimal, but I kind of want/wish to just punt that to Prisma lol, and let the "compiler" figure it out such that it optimizes to a findUnique automatically :D

I see NP usingfindUnique as an optimization. I'm not sure it makes a good starting place. If it is easier for you though, and makes the difference between shipping or not shipping, then ok.

[lvauvillier]

This solution comes from the old plugin too, i'm not sure if this is the more efficient but it solves all relation types without adding specific case to get the first item.

[jasonkuhrt]

How does findUnique work with lists e.g. 1:n relations?

Or is this PR only tackling non-list relations?

[lvauvillier]

here findUnique always retrieve the current root object. Then we let prisma client automatically retrieve related objects using the appropriate prisma client method.
So, Prisma client handle magically for us both 1-1 and 1-n :)

This is the logic implemented in the old plugin

[jasonkuhrt]

Ok this seems like a great start, it has been open long enough, let's keep things moving. Thanks @lvauvillier!

[jasonkuhrt]

@lvauvillier looks like tests are failing on CI, please fix that first 🙏

[lvauvillier]

I dont know how to solve the last CI issues:
e2e test never pass on my mac. When npm installs dependencies, they are not all present in the node_module of the generated project.

I also have no idea how to fix the eslint warnings. As we discussed, adding types to default resolver args is hard to solve...

[codecov-commenter]

Codecov Report

Merging #25 (b4985bb) into main (624c745) will decrease coverage by 0.02%.
The diff coverage is 15.09%.

@@            Coverage Diff             @@
##             main      #25      +/-   ##
==========================================
- Coverage   32.17%   32.15%   -0.03%     
==========================================
  Files          23       24       +1     
  Lines         317      367      +50     
  Branches       59       70      +11     
==========================================
+ Hits          102      118      +16     
- Misses        208      242      +34     
  Partials        7        7              

[jasonkuhrt]

Thanks @lvauvillier!

[rostislav-simonik-nexus-prisma-admin]

🎉 This PR is included in version 1.0.0 🎉

The release is available on:

• npm package (@next-major dist-tag)
• GitHub release

Your semantic-release bot 📦🚀