@nestjs-mod/graphql

GraphQL packages, providing an easy way to use GraphQL with the NestJS-mod, integrated: dataloader, included support for pipes, filters and interceptors in resolver fields, works with Fastify (Wrapper for https://docs.nestjs.com/graphql/quick-start)

Installation

npm i --save @nestjs/apollo @apollo/server @nestjs/graphql @as-integrations/fastify @nestjs-mod/graphql

Modules

Link	Category	Description
GraphqlModule	system	GraphQL packages, providing an easy way to use GraphQL with the NestJS-mod, integrated: dataloader, included support for pipes, filters and interceptors in resolver fields, works with Fastify (Wrapper for https://docs.nestjs.com/graphql/quick-start)

Modules descriptions

GraphqlModule

GraphQL packages, providing an easy way to use GraphQL with the NestJS-mod, integrated: dataloader, included support for pipes, filters and interceptors in resolver fields, works with Fastify (Wrapper for https://docs.nestjs.com/graphql/quick-start)

Use in NestJS

Example of main.ts

import { GRAPHQL_SCHEMA_FILE, GraphqlModule } from '@nestjs-mod/graphql';
import { Module } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { join } from 'path';
import { AppModule } from './app/app.module';

const rootFolder = join(__dirname, '..', '..', '..');
const appFolder = join(rootFolder, 'apps', 'example-graphql');

@Module({
  imports: [
    GraphqlModule.forRoot({
      configuration: {
        autoSchemaFile: join(appFolder, GRAPHQL_SCHEMA_FILE),
      },
    }),
    AppModule.forRoot(),
  ],
})
export class RootModule {}

async function bootstrap() {
  const app = await NestFactory.create(RootModule);
  await app.listen(3005);
}

bootstrap();

Example of dataloader

import { GraphqlDataLoader } from '@nestjs-mod/graphql';
import { Injectable } from '@nestjs/common';
import DataLoader from 'dataloader';
import { UserBalanceDto } from '../resolvers/dto/user-balance.dto';
import { BalanceOfUserService } from './balance-of-user.service';
@Injectable()
export class BalanceOfUserDataloader implements GraphqlDataLoader<number, UserBalanceDto> {
  constructor(private readonly balanceOfUserService: BalanceOfUserService) {}

  generateDataLoader(): DataLoader<number, UserBalanceDto> {
    return new DataLoader<number, UserBalanceDto>(async (userIds) =>
      this.balanceOfUserService.getUserBalanceByUserIds(userIds)
    );
  }
}

Examples of resolver fields with dataloader and without

/* eslint-disable @typescript-eslint/no-unused-vars */
import { getRequestFromExecutionContext } from '@nestjs-mod/common';
import { Loader } from '@nestjs-mod/graphql';
import { NestjsPinoAsyncLocalStorage, X_REQUEST_ID } from '@nestjs-mod/pino';
import { Logger } from '@nestjs/common';
import { Args, Parent, ResolveField, Resolver, Subscription } from '@nestjs/graphql';
import DataLoader from 'dataloader';
import { BalanceOfUserDataloader } from '../services/balance-of-user.data-loader';
import { BalanceOfUserService } from '../services/balance-of-user.service';
import { CHANGE_USER_BALANCE_EVENT, UserBalanceDto } from './dto/user-balance.dto';
import { UserDto } from './dto/user.dto';

@Resolver(UserDto)
export class BalanceOfUserResolver {
  constructor(private readonly balanceOfUserService: BalanceOfUserService) {}

  @ResolveField('balance', () => UserBalanceDto)
  async balance(
    @Parent()
    userDto: UserDto
  ): Promise<UserBalanceDto> {
    return (await this.balanceOfUserService.getUserBalanceByUserIds([userDto.id]))[0];
  }

  @ResolveField('balanceOverDataLoader', () => UserBalanceDto)
  async balanceOverDataLoader(
    @Parent()
    userDto: UserDto,
    @Loader(BalanceOfUserDataloader)
    balanceOfUserDataloader: DataLoader<number, UserBalanceDto>
  ) {
    return await balanceOfUserDataloader.load(userDto.id);
  }
}

Example of work with headers

import { Request } from '@nestjs-mod/common';
import { Args, Mutation, Query, Resolver } from '@nestjs/graphql';
import { StatusDto } from './dto/status.dto';
import { CreateUserDto, UserDto } from './dto/user.dto';

@Resolver()
export class UsersResolvers {
  static logger = new Logger(UsersResolvers.name);

  private readonly usersStorage: UserDto[] = [
    { id: 1, username: 'admin', custom: { one: 1 } },
    { id: 2, username: 'user', custom: { two: 2 } },
  ];

  constructor(private readonly balanceOfUserService: BalanceOfUserService) {}

  @Query(() => [UserDto])
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  async users(@Request() req: any): Promise<UserDto[]> {
    if (req.headers['x-throw-error']) {
      throw new Error('Error from query!');
    }
    return this.usersStorage;
  }

  @Mutation(() => StatusDto)
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  async createUser(@Request() req: any, @Args() userDto: CreateUserDto) {
    if (req.headers['x-throw-error']) {
      throw new Error('Error from mutation!');
    }
    this.usersStorage.push({ ...userDto, id: +userDto.id });
    return { status: 'OK' };
  }

  @Subscription(() => UserBalanceDto, {
    name: CHANGE_USER_BALANCE_EVENT,
    filter: (payload: UserBalanceDto, variables: { userId: string }) => {
      return payload.userId === +variables.userId;
    },
    resolve: (payload: UserBalanceDto, _args, ctx) => {
      const req = getRequestFromExecutionContext(ctx);
      BalanceOfUserResolver.logger.log({
        requestId: req.headers?.[X_REQUEST_ID],
      });
      // todo: requestId from request not apply in logger
      BalanceOfUserResolver.logger.log({ [CHANGE_USER_BALANCE_EVENT]: payload });
      if (req.headers['x-throw-error']) {
        throw new Error('Error from subscription!');
      }
      return payload;
    },
  })
  // eslint-disable-next-line @typescript-eslint/no-unused-vars
  onChangeUserBalance(@Args('userId') userId: string) {
    return this.balanceOfUserService.asyncIterator<UserBalanceDto>(CHANGE_USER_BALANCE_EVENT);
  }
}

Use in NestJS-mod

An example of using forRoot with parameters and use dataloader, resolver fields and subscriptions, you can see the full example here https://github.com/nestjs-mod/nestjs-mod-contrib/tree/master/apps/example-graphql.

import {
  DefaultNestApplicationInitializer,
  DefaultNestApplicationListener,
  InfrastructureMarkdownReportGenerator,
  PACKAGE_JSON_FILE,
  ProjectUtils,
  bootstrapNestApplication,
  isInfrastructureMode,
} from '@nestjs-mod/common';
import { FastifyNestApplicationInitializer, FastifyNestApplicationListener } from '@nestjs-mod/fastify';
import { GRAPHQL_SCHEMA_FILE, GraphqlModule } from '@nestjs-mod/graphql';
import { NestjsPinoLoggerModule } from '@nestjs-mod/pino';
import { ECOSYSTEM_CONFIG_FILE, Pm2 } from '@nestjs-mod/pm2';
import { TerminusHealthCheckModule } from '@nestjs-mod/terminus';
import { MemoryHealthIndicator } from '@nestjs/terminus';
import { join } from 'path';
import { AppModule } from './app/app.module';

const platform = process.env.PLATFORM === 'fastify' ? 'fastify' : 'express';

const rootFolder = join(__dirname, '..', '..', '..');
const appFolder = join(rootFolder, 'apps', 'example-graphql');

bootstrapNestApplication({
  modules: {
    system: [
      ProjectUtils.forRoot({
        staticConfiguration: {
          applicationPackageJsonFile: join(appFolder, PACKAGE_JSON_FILE),
          packageJsonFile: join(rootFolder, PACKAGE_JSON_FILE),
          envFile: join(rootFolder, '.env'),
        },
      }),
      platform === 'express'
        ? DefaultNestApplicationInitializer.forRoot({ staticConfiguration: { bufferLogs: true } })
        : FastifyNestApplicationInitializer.forRoot({ staticConfiguration: { bufferLogs: true } }),
      NestjsPinoLoggerModule.forRoot(),
      TerminusHealthCheckModule.forRootAsync({
        configurationFactory: (memoryHealthIndicator: MemoryHealthIndicator) => ({
          standardHealthIndicators: [
            { name: 'memory_heap', check: () => memoryHealthIndicator.checkHeap('memory_heap', 150 * 1024 * 1024) },
          ],
        }),
        inject: [MemoryHealthIndicator],
      }),
      platform === 'express'
        ? DefaultNestApplicationListener.forRoot({
            staticConfiguration: {
              // When running in infrastructure mode, the backend server does not start.
              mode: isInfrastructureMode() ? 'silent' : 'listen',
            },
          })
        : FastifyNestApplicationListener.forRoot({
            staticConfiguration: {
              // When running in infrastructure mode, the backend server does not start.
              mode: isInfrastructureMode() ? 'silent' : 'listen',
            },
          }),
      GraphqlModule.forRoot({
        configuration: {
          autoSchemaFile: join(appFolder, GRAPHQL_SCHEMA_FILE),
        },
      }),
    ],
    feature: [AppModule.forRoot()],
    infrastructure: [
      InfrastructureMarkdownReportGenerator.forRoot({
        staticConfiguration: {
          markdownFile: join(appFolder, 'INFRASTRUCTURE.MD'),
          skipEmptySettings: true,
        },
      }),
      Pm2.forRoot({
        configuration: {
          ecosystemConfigFile: join(rootFolder, ECOSYSTEM_CONFIG_FILE),
          applicationScriptFile: join('dist/apps/example-graphql/main.js'),
        },
      }),
    ],
  },
});

Configuration

Key	Description	Constraints	Default	Value
path	Path to mount GraphQL API	optional	/graphql	-
typeDefs	Type definitions	optional	-	-
typePaths	Paths to files that contain GraphQL definitions	optional	-	-
driver	GraphQL server adapter	optional	ApolloDriver extends apollo_base_driver_1.ApolloBaseDriver	-
include	An array of modules to scan when searching for resolvers	optional	-	-
directiveResolvers	Directive resolvers	optional	-	-
schema	Optional GraphQL schema (to be used or to be merged)	optional	-	-
resolvers	Extra resolvers to be registered.	optional	-	-
definitions	TypeScript definitions generator options	optional	-	-
autoSchemaFile	If enabled, GraphQL schema will be generated automatically	optional	schema.gql	-
sortSchema	Sort the schema lexicographically	optional	-	-
buildSchemaOptions	Options to be passed to the schema generator, only applicable if "autoSchemaFile" = true	optional	-	-
useGlobalPrefix	Prepends the global prefix to the url @see [faq/global-prefix](Global Prefix)	optional	-	-
fieldResolverEnhancers	Enable/disable enhancers for @ResolveField()	optional	[ interceptors, guards, filters ]	-
resolverValidationOptions	Resolver validation options.	optional	-	-
inheritResolversFromInterfaces	Inherit missing resolvers from their interface types defined in the resolvers object.	optional	-	-
transformSchema	Function to be applied to the schema letting you register custom transformations.	optional	-	-
transformAutoSchemaFile	Apply transformSchema to the autoSchemaFile	optional	-	-
context	Context function	optional	defaultContextFunction	-
metadata	Extra static metadata to be loaded into the specification	optional	-	-
installSubscriptionHandlers	If enabled, "subscriptions-transport-ws" will be automatically registered.	optional	true	-
subscriptions	Subscriptions configuration.	optional	{"graphql-ws":{"path":"/graphql"}}	-
playground	GraphQL playground options.	optional	{"settings":{"request.credentials":"include"}}	-
autoTransformHttpErrors	If enabled, will register a global interceptor that automatically maps "HttpException" class instances to corresponding Apollo errors.	optional	-	-

Back to Top

Links

• https://github.com/nestjs-mod/nestjs-mod - A collection of utilities for unifying NestJS applications and modules
• https://github.com/nestjs-mod/nestjs-mod-contrib - Contrib repository for the NestJS-mod
• https://github.com/nestjs-mod/nestjs-mod-example - Example application built with @nestjs-mod/schematics
• https://github.com/nestjs-mod/nestjs-mod/blob/master/apps/example-basic/INFRASTRUCTURE.MD - A simple example of infrastructure documentation.
• https://github.com/nestjs-mod/nestjs-mod-contrib/blob/master/apps/example-prisma/INFRASTRUCTURE.MD - An extended example of infrastructure documentation with a docker-compose file and a data base.
• https://dev.to/endykaufman/collection-of-nestjs-mod-utilities-for-unifying-applications-and-modules-on-nestjs-5256 - Article about the project NestJS-mod

License

MIT