GraphQL WS

GraphQL Websocket allows you to use the subscription feature of GraphQL using the Websocket transport protocol. This module is based on the graphql-ws (opens new window) package. It pre-configures the socket server and GraphQL server to work together.

Feature

• Support multiple GraphQL server
• Enable subscription feature of GraphQL

Installation

This module need to be used with @tsed/apollo module. So, you must install it before (see here).

import {Configuration} from "@tsed/common";
import "@tsed/platform-express";
import "@tsed/apollo";
import "@tsed/graphql-ws";
import {join} from "path";

@Configuration({
  apollo: {
    server1: {
      // GraphQL server configuration
      path: "/",
      playground: true, // enable playground GraphQL IDE. Set false to use Apollo Studio
      plugins: [], // Apollo plugins

      wsServerOptions: {
        // See options descriptions on
      },
      wsUseServerOptions: {
        // See options descriptions on GraphQL WS
      }

      // Give custom server instance
      // server?: (config: Config) => ApolloServer;

      // ApolloServer options
      // ...
      // See options descriptions on https://www.apollographql.com/docs/apollo-server/api/apollo-server.html
    }
  },
  graphqlWs: {
    // global options
    wsServerOptions: {
      // See options descriptions on
    },
    wsUseServerOptions: {
      // See options descriptions on
    }
  }
})
export class Server {}

Register plugins

You can register plugins with the plugins property. The plugins are executed in the order of declaration.

import {Configuration} from "@tsed/common";
import "@tsed/platform-express";
import "@tsed/apollo";
import {join} from "path";

@Configuration({
  apollo: {
    server1: {
      plugins: [] // Apollo plugins
    }
  }
})
export class Server {}

But if you need to register and access to the injector, you can use the $alterApolloServerPlugins hook. For example, you can register the graphql-ws necessary to support the subscription feature of GraphQL like this:

import {Constant, Inject, InjectorService, Module} from "@tsed/di";
import {useServer} from "graphql-ws/lib/use/ws";
import Http from "http";
import Https from "https";
import {WebSocketServer} from "ws";
import {GraphQLWSOptions} from "./GraphQLWSOptions";

@Module()
export class GraphQLWSModule {
  @Constant("graphqlWs", {})
  private settings: GraphQLWSOptions;

  @Inject(Http.Server)
  private httpServer: Http.Server | null;

  @Inject(Https.Server)
  private httpsServer: Https.Server | null;

  @Inject()
  private injector: InjectorService;

  createWSServer(settings: GraphQLWSOptions) {
    const wsServer = new WebSocketServer({
      ...(this.settings.wsServerOptions || {}),
      ...settings.wsServerOptions,
      server: this.httpsServer || this.httpServer!,
      path: settings.path
    });

    return useServer(
      {
        ...(this.settings.wsUseServerOptions || {}),
        ...settings.wsUseServerOptions,
        schema: settings.schema
      },
      wsServer
    );
  }

  async $alterApolloServerPlugins(plugins: any[], settings: GraphQLWSOptions) {
    const wsServer = await this.createWSServer(settings);

    this.injector.logger.info(`Create GraphQL WS server on: ${settings.path}`);

    return plugins.concat({
      serverWillStart() {
        return {
          async drainServer() {
            await wsServer.dispose();
          }
        };
      }
    } as any);
  }
}

Note

Ts.ED provide a @tsed/graphql-ws package to support the subscription feature of GraphQL. See here (opens new window) for more details.

Nexus

Installation

Now, we can configure the Ts.ED server by importing @tsed/apollo in your Server:

import {Configuration} from "@tsed/common";
import "@tsed/platform-express";
import "@tsed/apollo";
import {schema} from "./schema";
import {join} from "path";

@Configuration({
  apollo: {
    server1: {
      // GraphQL server configuration
      path: "/",
      playground: true, // enable playground GraphQL IDE. Set false to use Apollo Studio
      schema,
      plugins: [] // Apollo plugins

      // Give custom server instance
      // server?: (config: Config) => ApolloServer;

      // ApolloServer options
      // ...
      // See options descriptions on https://www.apollographql.com/docs/apollo-server/api/apollo-server.html
    }
  }
})
export class Server {}

Then create schema/index.ts:

import {makeSchema} from "nexus";
import {join} from "path";

export const schema = makeSchema({
  types: [], // 1
  outputs: {
    typegen: join(process.cwd(), "..", "..", "nexus-typegen.ts"), // 2
    schema: join(process.cwd(), "..", "..", "schema.graphql") // 3
  }
});

TypeGraphQL

Installation

To begin, install the @tsed/typegraphql package:

Now, we can configure the Ts.ED server by importing @tsed/typegraphql in your Server:

Types

We want to get the equivalent of this type described in SDL:

type Recipe {
  id: ID!
  title: String!
  description: String
  creationDate: Date!
  ingredients: [String!]!
}

So we create the Recipe class with all properties and types:

class Recipe {
  id: string;
  title: string;
  description?: string;
  creationDate: Date;
  ingredients: string[];
}

Then we decorate the class and its properties with decorators:

import {Field, ID, ObjectType} from "type-graphql";

@ObjectType()
export class Recipe {
  @Field((type) => ID)
  id: string;

  @Field()
  title: string;

  @Field({nullable: true})
  description?: string;

  @Field()
  creationDate: Date;

  @Field((type) => [String])
  ingredients: string[];
}

The detailed rules for when to use nullable, array and others are described in fields and types docs (opens new window).

Resolvers

After that we want to create typical crud queries and mutation. To do that we create the resolver (controller) class that will have injected RecipeService in the constructor:

import {Inject} from "@tsed/di";
import {ResolverController} from "@tsed/typegraphql";
import {Arg, Args, Query} from "type-graphql";
import {RecipeNotFoundError} from "../errors/RecipeNotFoundError";
import {RecipesService} from "../services/RecipesService";
import {Recipe} from "../types/Recipe";
import {RecipesArgs} from "../types/RecipesArgs";

@ResolverController(Recipe)
export class RecipeResolver {
  @Inject()
  private recipesService: RecipesService;

  @Query((returns) => Recipe)
  async recipe(@Arg("id") id: string) {
    const recipe = await this.recipesService.findById(id);
    if (recipe === undefined) {
      throw new RecipeNotFoundError(id);
    }

    return recipe;
  }

  @Query((returns) => [Recipe])
  recipes(@Args() {skip, take}: RecipesArgs) {
    return this.recipesService.findAll({skip, take});
  }
}

Multiple GraphQL server

If you register multiple GraphQL servers, you must specify the server id in the @ResolverController decorator.

@ResolverController(Recipe, {id: "server1"})

Another solution is to not use @ResolverController (use @Resolver from TypeGraphQL), and declare explicitly the resolver in the server configuration:

@Configuration({
  graphql: {
    server1: {
      resolvers: {
        RecipeResolver
      }
    },
    server2: {
      resolvers: {
        OtherResolver
      }
    }
  }
})

Data Source

Data source is one of the Apollo server features which can be used as option for your Resolver or Query. Ts.ED provides a DataSourceService decorator to declare a DataSource which will be injected to the Apollo server context.

import {DataSource} from "@tsed/typegraphql";
import {RESTDataSource} from "apollo-datasource-rest";
import {User} from "../models/User";
@DataSource()
export class UserDataSource extends RESTDataSource {
  constructor() {
    super();
    this.baseURL = "https://myapi.com/api/users";
  }

  getUserById(id: string): Promise<User> {
    return this.get(`/${id}`);
  }
}

Then you can retrieve your data source through the context in your resolver like that:

import {ResolverController} from "@tsed/typegraphql";
import {Arg, Authorized, Ctx, Query} from "type-graphql";
import {UserDataSource} from "../datasources/UserDataSource";
import {User} from "../models/User";

@ResolverController(User)
export class UserResolver {
  @Authorized()
  @Query(() => User)
  public async user(@Arg("userId") userId: string, @Ctx("dataSources") dataSources: any): Promise<User> {
    const userDataSource: UserDataSource = dataSources.userDataSource;

    return userDataSource.getUserById(userId);
  }
}

Get Server instance

ApolloService (or TypeGraphQLService) lets you to retrieve an instance of ApolloServer.

import {AfterRoutesInit} from "@tsed/common";
import {Inject, Injectable} from "@tsed/di";
import {ApolloService} from "@tsed/apollo";
import {ApolloServer} from "apollo-server-express";

@Injectable()
export class UsersService implements AfterRoutesInit {
  @Inject()
  private ApolloService: ApolloService;
  // or private typeGraphQLService: TypeGraphQLService;

  private server: ApolloServer;

  $afterRoutesInit() {
    this.server = this.apolloService.get("server1")!;
  }
}

For more information about ApolloServer, look at its documentation here (opens new window);

Testing

Here is an example to create a test server based on TypeGraphQL and run a query:

TIP

The unit example is also available to test any Apollo Server!

Author

Maintainers

Become maintainer