graphErr: A TypeScript repository from Open Source Labs Beta

GraphErr

Descriptive GraphQL error handling for Deno/Oak servers.

Features

Provides additional context to GraphQL's native error messaging for faster debugging.
- Classifies the error type and includes a link to the GraphQL spec for more information about the error.
Gives descriptive error messages to null responses, identifying the cause of the issue.
- Traditionally, GraphQL null responses lack error messaging.
Enables quick development of GraphQL-equipped router.
Generates GraphQL Playground IDE, allowing developers to write and execute queries.

Getting Started with GraphErr

Below is an example of a basic server you can use to run GraphErr. This server will run on http://localhost:3000/graphql by default.

import { applyGraphQL } from "https://deno.land/x/grapherr/applyGQL.ts";
import { Application, Router } from "https://deno.land/x/oak/mod.ts";
import { gql } from 'https://deno.land/x/graphql_tag/mod.ts';

const app = new Application();

// Define the GQL schema using GraphQL-tag (gql). More information on GraphQL-tag below in the README.
const typeDefs = gql`
  type Query {
    allUsers: [User!]!
  }
  type User {
    _id: ID!
    username: String!
    password: String!
  }
`;

// Define resolvers
const resolvers = {
  Query: {
    allUsers: () => {
      return [
      { _id: 1, username: 'JohnDoe', password: 'Password123!' }, 
      { _id: 2, username: 'JaneDoe', password: 'Password1234!!' }
      ]
    },
  },
};

const GraphQLService = await applyGraphQL<Router>({
  Router,
  typeDefs: typeDefs,
  resolvers: resolvers,
})

app.use(GraphQLService.routes(), GraphQLService.allowedMethods());

await app.listen({ port: 3000 });

Please import all necessary 3rd party modules (graphErr, oak, and gql).
- Oak is a middleware framework for handling HTTP requests.
- GraphQL-tag (gql) is a Javascript template literal tag that parses GraphQL query strings into the standard GraphQL AST.
Define typedefs (using GraphQL-tag) and resolvers and pass both into applyGraphQL as shown in the code above.
ApplyGQL accepts four arguments:
- Router: oak Router module
- path?: string
  - A target path that handles the GraphQL post request (*optional: default as /graphql)
- typeDefs: any
  - generated type tags by the gql
- resolvers: any
  - An object that handles the queries and mutations
ApplyGQL utilizes code from the Oak-GraphQL module. For additional information on ApplyGQL, please check out the OakGQL repository.