April 21, 2020 by Tomek

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 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.