Nest.js 构建期间生成 GraphQL 模式

Question

我正在使用带有 NestJS 的代码优先方法来处理 GraphQL，并使用 Nx 设置 monorepo。

schema.gql

仅在我运行服务器时产生，而在 CI 期间我无法做到这一点。将整个存储库复制到 docker 映像并启动服务器对我来说是不切实际的。当您构建嵌套应用程序时，不会生成

schema.gql

。

我还查看了 NestJS 网站上的手动生成 SDL 文档，但不太确定如何集成该脚本。

只是想知道是否有人在不启动服务器的情况下成功生成了模式？

Answer 1

以下内容对我来说效果很好。我在这里的文档中发现了这一点：

https://docs.nestjs.com/graphql/quick-start#accessing- generated-schema

我添加了一个检查来查看 ENV 是否是生产环境，因为我想要生成文件的位置在开发模式下已经存在。

import { NestFactory } from '@nestjs/core';
import { GraphQLSchemaHost } from '@nestjs/graphql';
import { writeFileSync } from 'fs';
import { printSchema } from 'graphql';
import { join } from 'path';
import { ServerModule } from './server.module';

async function bootstrap() {
  const app = await NestFactory.create(ServerModule);
  await app.listen(process.env.PORT || 3001);

  if (process.env.NODE_ENV === 'production') {
    const { schema } = app.get(GraphQLSchemaHost);
    writeFileSync(join(process.cwd(), `/src/schema.gql`), printSchema(schema));
  }
}
bootstrap();

Answer 2

设法弄清楚如何集成手动生成SDL。

只需在启动 Nest 服务器之前执行生成 SDL 函数即可。

下面包含完整示例。

const resolvers = [MyResolver]

/**
 * Generate GraphQL schema manually. NestJS does not generate the GraphQL schema
 * automatically during the build process and it doesn't generate the GraphQL
 * schema when starting the built app. This schema needs to be generated or
 * the GraphQL api would have nothing to use.
 *
 * @param {MyServices} serviceName - Name of the gavel service to generate a unique
 * schema.
 * @param {Function[]} resolvers - List of GraphQL resolvers being used in that app.
 * @returns {Promise<void>} Nothing gets returned. It will just write the schema and
 * throw an error if it fails.
 */
export async function generateGraphQLSchema(
  serviceName: MyServices,
  resolvers: Function[],
): Promise<void> {
  const app = await NestFactory.create(GraphQLSchemaBuilderModule)
  await app.init()

  const gqlSchemaFactory = app.get(GraphQLSchemaFactory)
  const schema = await gqlSchemaFactory.create(resolvers)

  writeFileSync(join(process.cwd(), `/${serviceName}-schema.gql`), printSchema(schema))
}

/**
 * Setup nest application.
 *
 * @param {string} port - Port the application should listen to.
 * @param {unknown} appModule - Main app module from a nest application.
 * @param {MyServices} serviceName - Name of the gavel service to generate a unique
 * schema.
 * @returns {Promise<void>}
 */
async function bootstrap(port: string, appModule: any, serviceName: MyServices): Promise<void> {
  const app = await NestFactory.create(appModule)

  // Endpoint prefix
  const globalPrefix = `${config.get(`env`)}/v1/${serviceName}`
  app.setGlobalPrefix(globalPrefix)

  // Start Server
  await app.listen(port, () => {
    Logger.log(`Listening at http://localhost:${port}/${globalPrefix}/graphql`)
  })
}

/**
 * Helper to crate standard Nest JS Server.
 *
 * @param {MyServices} serviceName - Name of service.
 * @param {unknown} appModule - Main app module from a nest application.
 */
export function initializeServer(serviceName: GavelService, appModule: any): void {
  const environment = config.get(`env`)
  const port = config.get(`port`)
  initializeElasticApm(`service-${serviceName}`, {
    framework: `nest`,
    environment,
    version: `${packageJson.version}`,
  })
  bootstrap(port, appModule, serviceName).catch((error) => {
    const logger = getElasticSearchLogger(serviceName)
    logger.error(
      { error, environment: config.get(`env`), applicationName: serviceName },
      error.message,
    )
  })
}

generateGraphQLSchema(MyServices.SERVICE_A, resolvers)
  .then(() => initializeServer(MyServices.SERVICE_A, AppModule))
  .catch((e) => console.error(e))

Answer 3

更简单地实现手动生成 SDL

如果您使用 graphql cli 插件，请从

nest start --entryFile generate-schema

开始

src/generate-schema.ts

import { NestFactory } from '@nestjs/core';
import { GraphQLSchemaBuilderModule, GraphQLSchemaFactory } from '@nestjs/graphql';
import { writeFileSync } from 'fs';
import { printSchema } from 'graphql';
import { join } from 'path';

const resolvers = [
  // Your resolvers here
];

const scalars = [
  // Your scalars here
];

const main = async () => {
  const app = await NestFactory.create(GraphQLSchemaBuilderModule);
  await app.init();

  const gqlSchemaFactory = app.get(GraphQLSchemaFactory);
  const schema = await gqlSchemaFactory.create(resolvers, scalars);

  writeFileSync(join(process.cwd(), '/schema.graphql'), printSchema(schema));
};
main();