Generate GraphQL resolvers easily with GraphQL Centaur

GraphQL Centaur is a CLI tool with a goal to provide seamless experience creating GraphQL as a service.

GraphQL Centaur generates Mongo/Stucco-js database resolvers in TypeScript from any give GraphQL Schema.

Generate fully-functional basic resolvers with Centaur CLI, customize them the way that suits your project and enjoy your GraphQL based backend.

Installation

If you want to install GraphQL Centaur globally run:

npm i -g graphql-centaur

to install it inside your backend repo performer:

npm i graphql-centaur

then use with npx or as a package.json script.

Database	Support
MongoDB	YES
JavaScript	YES
TypeScript	YES
PostgreSQL	SOON

Resolver generation

First time when you generate a resolver centaur will also generate needed libraries for collections, DB, Utils and [graphql-zeus](https://github.com/graphql-editor/graphql-zeus) definitions, then given the following schema:

type Person{
    firstName: String!
}
type Query{
    people: [Person]!
}
schema{
    query: Query
}

after choosing the following elements:

• Query
• people
• CRUD
• listFilter

GraphQL Centaur should generate TypeScript resolver placed in $src/Query/people.ts directory:

import { FieldResolveInput, FieldResolveOutput } from 'stucco-js';
import { PersonCollection } from '../db/collections';
import { DB } from '../db/mongo';
import { Utils } from '../Utils';
import { Person, ResolverType, ValueTypes } from '../graphql-zeus';

export const handler = async (): Promise<FieldResolveOutput> => {
  const db = await DB();
  const col = await db.collection(PersonCollection);
  return Utils.CursorToGraphQLArray<Person>(await col.find({}));
};

and append correct entries to the stucco.json file:

{
    "resolvers":{
        "Query.people":{
            "resolve":{
                "name":"lib/Query/people"
            }
        }
    }
}

After running Stucco-js, your resolver should work out of the box. Of course, some resolver types, however, might need a little bit of custom code to make them work the way you want, but basically you have just generated your GraphQL Backend!

Available Resolvers

Resolvers are split into the following categories:

Category	Resolver	Desc
CRUD	Create	Create an object in your database and return it
CRUD	Update	Update an object in your database and return it
CRUD	List	List all objects of selected type
CRUD	Get by parameter	Get object by parameter from the database
CRUD	Remove	Remove an object from the database and return true
COMMON	Pipe	Pipe the arguments of the query as the source for the next resolver
COMMON	Resolver	Simple Resolver you need to write
COMMON	Rest	Rest proxy resolvers for pointing to existing REST APIs
COMMON	Source	A Resolver that receives source from the parent resolver
COMMON	SourcedCRUD	The same as CRUD, but also use source

GraphQL Centaur is also compatible with GraphQL Editor projects.