How to integrate neo4j-graphql-js into nestjs w/Graphql

[mail2michaelenn]

I am experimenting with Nestjs, graphql, and neo4j-graphql with augmented schema. I am interested if anyone doing any work in this area. The main challenge I am having relates to neo4j-graphql-js and the code-first concept. So from my understanding neo4j-graphql-js in based on the Schema-first approach...is this correct? and if this is so what kind of workaround can be done to fit in the code-first approach. If this is not so...are there any available example of how this works.

[david_allen]

I'm not sure what you mean by code first approach, can you clarify?

yes with neo4j-graphql-js, generally you start by coming up with a GraphQL schema / set of typedefs and resolvers. The resolvers can of course be JS code, but the typedefs aren't.

There are a number of folks doing work in this area but it'd help if you could narrow down what you're trying to do, what you've tried, and what you want to do.

[mail2michaelenn]

The Nestjs graphql docs(https://docs.nestjs.com/graphql/quick-start) speaks to Schema First and Code First. The code first (resolver first) approach uses the type-graphql library to generate the schema from the resolvers....apparently this approach was introduced to solve scalability and single-source of truth for the schema. I am looking at Christian Lutz response to a similar question (https://stackoverflow.com/questions/53544876/how-to-integrate-neo4j-database-nestjs-framework-and-gr...) where he suggested using Nest Interceptor with the schema first approach. What I am trying to do is implement the code first approach using type-graphql and neo4j-graphql. In essence I want to go from my standard Nest/REST approach of xyz-controller --> xyz-service-->neo4j-service to a Nest/graphql/neo4j structure using the code first approach.

[david_allen]

I am still not 100% sure I'm following, and I may just not be the right person to answer this.

On the note of generating the schema, this can be done from an existing Neo4j Database: https://blog.grandstack.io/inferring-graphql-type-definitions-from-an-existing-neo4j-database-dadca2... but "generating the schema from the resolvers" doesn't fully parse for me and I can't advise.

[mail2michaelenn]

Thanks David...I agree it's not quite clear what's going on...so I am going to do some trial and error.

-Michael

[William_Lyon]

Hey @mail2michaelennis -

You can do "code first GraphQL" with neo4j-graphql.js by passing a GraphQL schema object to makeAugmentedSchema or augmentSchema. I'm not too familiar with Nest, but if you are using it to create a GraphQL schema object, you can pass that to makeAugmentedSchema from neo4j-graphql.js to add the auto-generated resolvers, instead of SDL type definitions:

const schema = makeAugmentedSchema({schema: mySchema})

In that stackoverflow answer it looks like they are passing augmentSchema to a transformSchema step.

[mail2michaelenn]

Yes....I can see that if we have a schema created we can pass it through the augmentSchema function. The problem is in the Nest version it's not clear how the schema (schema.gql) is created. Apparently the type-graphql library builds it on startup of the app but this is not clear. I will test this view to see it it works....Thanks for the input.

[arnleiftordal]

@mail2michaelennis what solution did you land on?