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@nestjs-mod/common

A collection of utilities for unifying NestJS applications and modules

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Installation​

npm i --save @nestjs-mod/common

Utilities​

LinkDescription
Config modelDecorators for describing the module configuration and a function for its serialization and validation.
Env modelDecorators for describing module environment variables and functions for its serialization and verification.
NestJS applicationFunction for sequential import of nestModules.
NestJS moduleFunction for creating a configurable module with the ability to use multi-providing.

Modules​

LinkCategoryDescription
InfrastructureMarkdownReportGeneratorinfrastructureInfrastructure markdown report generator.
InfrastructureMarkdownReportStorageinfrastructureInfrastructure markdown report storage
DefaultNestApplicationInitializersystemDefault NestJS application initializer.
DefaultNestApplicationListenersystemDefault NestJS application listener.
ProjectUtilssystemUtilities for setting global application parameters, such as project name, description, and settings validation parameters.

Utilities descriptions​

Config model​

Decorators for describing the module configuration and a function for its serialization and validation. Values for this type of configuration must be described in code.

Decorators​

ConfigModel, ConfigModelProperty

Function​

configTransform

Usage​

import { ConfigModel, ConfigModelProperty, configTransform } from '@nestjs-mod/common';
import { DynamicModule, Module } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { IsNotEmpty } from 'class-validator';

// We describe the configuration.
@ConfigModel()
class AppConfig {
  @ConfigModelProperty()
  @IsNotEmpty()
  option!: string;
}

// We describe the module.
@Module({ providers: [AppConfig] })
class AppModule {
  static forRoot(config: Partial<AppConfig>): DynamicModule {
    return {
      module: AppModule,
      providers: [
        {
          provide: `${AppConfig.name}_loader`,
          useFactory: async (emptyAppConfig: AppConfig) => {
            if (config.constructor !== Object) {
              Object.setPrototypeOf(emptyAppConfig, config);
            }
            const obj = await configTransform({
              model: AppConfig,
              data: config,
            });
            Object.assign(emptyAppConfig, obj.data);
          },
          inject: [AppConfig],
        },
      ],
    };
  }
}

// Let's try to launch the application - Example with throw validation error.
async function bootstrap1() {
  const app = await NestFactory.create(AppModule.forRoot({}));
  await app.listen(3000);
}

// Now we get a config validation error.
// throw new ConfigModelValidationErrors(validateErrors);
// isNotEmpty: option should not be empty
bootstrap1();

// Let's try to launch the application - Example of start without error.
async function bootstrap2() {
  const app = await NestFactory.create(AppModule.forRoot({ option: 'value1' }));
  console.log(app.get(AppConfig)); // output: { option: 'value1' }
  await app.listen(3000);
}

bootstrap2();

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Env model​

Decorators for describing module environment variables and functions for its serialization and verification. Values can be automatically read from process.env.

Decorators​

EnvModel, EnvModelProperty

Function​

envTransform

Usage​

import { EnvModel, EnvModelProperty, envTransform } from '@nestjs-mod/common';
import { DynamicModule, Module } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { IsNotEmpty } from 'class-validator';

// We describe the configuration.
@EnvModel()
class AppEnv {
  @EnvModelProperty()
  @IsNotEmpty()
  option!: string;
}

// We describe the module.
@Module({ providers: [AppEnv] })
class AppModule {
  static forRoot(env: Partial<AppEnv>): DynamicModule {
    return {
      module: AppModule,
      providers: [
        {
          provide: `${AppEnv.name}_loader`,
          useFactory: async (emptyAppEnv: AppEnv) => {
            if (env.constructor !== Object) {
              Object.setPrototypeOf(emptyAppEnv, env);
            }
            const obj = await envTransform({
              model: AppEnv,
              data: env,
            });
            Object.assign(emptyAppEnv, obj.data);
          },
          inject: [AppEnv],
        },
      ],
    };
  }
}

// Let's try to launch the application - Example with throw validation error.
async function bootstrap1() {
  const app = await NestFactory.create(AppModule.forRoot({}));
  await app.listen(3000);
}

// Now we get a config validation error.
// throw new ConfigModelValidationErrors(validateErrors);
// isNotEmpty: option should not be empty
bootstrap1();

// Let's try to launch the application - Example of start without error.
async function bootstrap2() {
  const app = await NestFactory.create(AppModule.forRoot({ option: 'value1' }));
  console.log(app.get(AppEnv)); // output: { option: 'value1' }
  await app.listen(3000);
}

bootstrap2();

// Let's try to launch the application - Example of use environment variables and start without error.
async function bootstrap3() {
  process.env['OPTION'] = 'value1';
  const app = await NestFactory.create(AppModule.forRoot({}));
  console.log(app.get(AppEnv)); // output: { option: 'value1' }
  await app.listen(3000);
}

bootstrap3();

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NestJS application​

Function for sequential import of nestModules. When importing, all preWrapApplication methods of modules are run at the beginning, then all wrapApplication methods, and at the very end all postWrapApplication methods.

Types of modules (list in order of processing):

  • System modules - System modules necessary for the operation of the entire application (examples: launching a NestJS application, launching microservices, etc.). Only NestJS-mod compatible modules.
  • Core modules - Core modules necessary for the operation of feature and integration modules (examples: main module with connection to the database, main module for connecting to aws, etc.). NestJS and NestJS-mod compatible modules.
  • Feature modules - Feature modules with business logic of the application. NestJS and NestJS-mod compatible modules.
  • Integration modules - Integration modules are necessary to organize communication between feature or core modules (example: after creating a user in the UsersModule feature module, you need to send him a letter from the NotificationsModule core module). NestJS and NestJS-mod compatible modules.
  • Infrastructure modules - Infrastructure modules are needed to create configurations that launch various external services (examples: docker-compose file for raising a database, gitlab configuration for deploying an application). Only NestJS-mod compatible modules.

Function​

bootstrapNestApplication

Usage​

import {
  isInfrastructureMode,
  DefaultNestApplicationInitializer,
  DefaultNestApplicationListener,
  EnvModel,
  EnvModelProperty,
  bootstrapNestApplication,
  createNestModule,
} from '@nestjs-mod/common';
import { Injectable } from '@nestjs/common';
import { IsNotEmpty } from 'class-validator';

@EnvModel()
class AppEnv {
  @EnvModelProperty()
  @IsNotEmpty()
  option!: string;
}

@Injectable()
class AppService {
  constructor(private readonly appEnv: AppEnv) {}

  getEnv() {
    return this.appEnv;
  }
}

const { AppModule } = createNestModule({
  moduleName: 'AppModule',
  environmentsModel: AppEnv,
  providers: [AppService],
});

process.env['OPTION'] = 'value1';

bootstrapNestApplication({
  modules: {
    system: [
      DefaultNestApplicationInitializer.forRoot(),
      DefaultNestApplicationListener.forRoot({
        staticEnvironments: { port: 3000 },
        staticConfiguration: {
          preListen: async ({ app }) => {
            if (app) {
              const appService = app.get(AppService);
              console.log(appService.getEnv()); // output: { option: 'value1' }
            }
          },
        },
      }),
    ],
    feature: [AppModule.forRoot()],
  },
});

Usage with project name and contextName​

  isInfrastructureMode,
import {
  DefaultNestApplicationInitializer,
  DefaultNestApplicationListener,
  EnvModel,
  EnvModelProperty,
  bootstrapNestApplication,
  createNestModule,
} from '@nestjs-mod/common';
import { Injectable } from '@nestjs/common';
import { IsNotEmpty } from 'class-validator';

@EnvModel()
class AppEnv {
  @EnvModelProperty()
  @IsNotEmpty()
  option!: string;
}

@Injectable()
class AppService {
  constructor(private readonly appEnv: AppEnv) {}

  getEnv() {
    return this.appEnv;
  }
}

const { AppModule } = createNestModule({
  moduleName: 'AppModule',
  environmentsModel: AppEnv,
  providers: [AppService],
});

process.env['TEST_APP_CTX_OPTION'] = 'value1';

bootstrapNestApplication({
  project: { name: 'TestApp', description: 'Test application' },
  modules: {
    system: [
      DefaultNestApplicationInitializer.forRoot(),
      DefaultNestApplicationListener.forRoot({
        staticEnvironments: { port: 3000 },
        staticConfiguration: {
          preListen: async ({ app }) => {
            if (app) {
              const appService = app.get(AppService);
              console.log(appService.getEnv()); // output: { option: 'value1' }
            }
          },
        },
      }),
    ],
    feature: [AppModule.forRoot({ contextName: 'CTX' })],
  },
});

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NestJS module​

Function for creating a configurable module with the ability to use multi-providing. It is possible to create and work with named module instances. Modules can contain code for creating and managing the application (preWrapApplication, wrapApplication, postWrapApplication).

Type of config or env models used in module:

  • environmentsModel - Variables with primitive types used in the module, the values of which can be obtained from various sources, such as: process.env or consul key value.
  • configurationModel - Variables of primitive and complex types that are used in the module; values for them must be passed when connecting the module to the application.
  • staticEnvironmentsModel - Static variables with primitive types used in the module and can be used at the time of generating module metadata (import, controllers), the values of which can be obtained from various sources, such as: process.env or consul key value.
  • staticConfigurationModel - Static variables of primitive and complex types that are used in the module and can be used at the time of generating module metadata (import, controllers); values for them must be passed when connecting the module to the application.
  • featureConfigurationModel - Feature variables of primitive and complex types that can be added to the current module from other modules (example: a transport for sending a message can be defined as a generalized interface, but the implementation itself will be added from a module for working with a specific transport or from an integration module).
  • featureEnvironmentsModel - Feature variables with primitive types used in the module, the values of which can be obtained from various sources, such as: process.env or consul key value.

Decorators​

InjectFeatures, InjectService, InjectAllFeatures, InjectFeatureEnvironments, InjectAllFeatureEnvironments

Function​

createNestModule, getNestModuleDecorators

Usage​

import {
  ConfigModel,
  ConfigModelProperty,
  EnvModel,
  EnvModelProperty,
  createNestModule,
  getNestModuleDecorators,
  InjectableFeatureConfigurationType,
} from '@nestjs-mod/common';
import { Injectable } from '@nestjs/common';
import { NestFactory } from '@nestjs/core';
import { IsNotEmpty } from 'class-validator';

// App1Module

const { InjectFeatures } = getNestModuleDecorators({
  moduleName: 'App1Module',
});

@ConfigModel()
class AppFeatureConfig {
  @ConfigModelProperty()
  @IsNotEmpty()
  featureOptionConfig!: string;
}

@Injectable()
class AppFeaturesService {
  constructor(
    @InjectFeatures()
    private readonly appFeatureConfigs: InjectableFeatureConfigurationType<AppFeatureConfig>[]
  ) {}

  getFeatureConfigs() {
    return this.appFeatureConfigs.map(({ featureConfiguration }) => featureConfiguration);
  }
}

const { App1Module } = createNestModule({
  moduleName: 'App1Module',
  sharedProviders: [AppFeaturesService],
  featureConfigurationModel: AppFeatureConfig,
});

@ConfigModel()
class App2Config {
  @ConfigModelProperty()
  @IsNotEmpty()
  option!: string;
}

@Injectable()
class App2Service {
  constructor(private readonly appFeaturesService: AppFeaturesService, private readonly app2Config: App2Config) {}

  getFeatureConfigs() {
    return this.appFeaturesService.getFeatureConfigs();
  }

  getConfig() {
    return this.app2Config;
  }
}

// App2Module

const { App2Module } = createNestModule({
  moduleName: 'App2Module',
  imports: [
    App1Module.forFeature({
      featureModuleName: 'App2Module',
      featureConfiguration: { featureOptionConfig: 'featureOptionConfig-app2' },
    }),
  ],
  providers: [App2Service],
  configurationModel: App2Config,
});

@EnvModel()
class App3Env {
  @EnvModelProperty()
  @IsNotEmpty()
  option!: string;
}

@Injectable()
class App3Service {
  constructor(private readonly appFeaturesService: AppFeaturesService, private readonly app3Env: App3Env) {}

  getFeatureConfigs() {
    return this.appFeaturesService.getFeatureConfigs();
  }

  getEnv() {
    return this.app3Env;
  }
}

const { App3Module } = createNestModule({
  moduleName: 'App3Module',
  imports: [
    App1Module.forFeature({
      featureModuleName: 'App2Module',
      featureConfiguration: { featureOptionConfig: 'featureOptionConfig-app3' },
    }),
  ],
  providers: [App3Service],
  environmentsModel: App3Env,
});

const { AppModule } = createNestModule({
  moduleName: 'AppModule',
  imports: [
    App1Module.forRoot(),
    App2Module.forRoot({ configuration: { option: 'appConfig3value' } }),
    App3Module.forRoot({ environments: { option: 'appEnv2value' } }),
  ],
});

async function bootstrap() {
  const app = await NestFactory.create(AppModule.forRoot());
  const appFeatureScannerService = app.get(AppFeaturesService);
  const app2Service = app.get(App2Service);
  const app3Service = app.get(App3Service);

  console.log(appFeatureScannerService.getFeatureConfigs()); // output: [{ featureOptionConfig: 'featureOptionConfig-app2' }, { featureOptionConfig: 'featureOptionConfig-app3' }]
  console.log(app2Service.getFeatureConfigs()); // output: [{ featureOptionConfig: 'featureOptionConfig-app2' }, { featureOptionConfig: 'featureOptionConfig-app3' }]
  console.log(app3Service.getFeatureConfigs()); // output: [{ featureOptionConfig: 'featureOptionConfig-app2' }, { featureOptionConfig: 'featureOptionConfig-app3' }]
  console.log(app2Service.getConfig()); // output: { option: 'appConfig3value' }
  console.log(app3Service.getEnv()); // output: { option: 'appEnv2value' }
}

bootstrap();

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Modules descriptions​

InfrastructureMarkdownReportGenerator​

Infrastructure markdown report generator.

Use in NestJS-mod​

Use with options.

import { bootstrapNestApplication, InfrastructureMarkdownReportGenerator } from '@nestjs-mod/common';
import { join } from 'path';

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

bootstrapNestApplication({
  modules: {
    infrastructure: [
      InfrastructureMarkdownReportGenerator.forRoot({
        staticConfiguration: {
          markdownFile: join(appFolder, 'INFRASTRUCTURE.MD'),
          skipEmptySettings: true,
        },
      }),
    ],
  },
});

Shared providers​

DynamicNestModuleMetadataMarkdownReportGenerator

Static configuration​

KeyDescriptionConstraintsDefaultValue
markdownFileName of the markdown-file in which to save the infrastructure reportoptional--
skipEmptySettingsSkip empty values of env and config modelsoptional--

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InfrastructureMarkdownReportStorage​

Infrastructure markdown report storage

Use in NestJS-mod​

Use the forRoot method to create a global report store.

import { bootstrapNestApplication, InfrastructureMarkdownReportStorage } from '@nestjs-mod/common';

bootstrapNestApplication({
  modules: {
    infrastructure: [InfrastructureMarkdownReportStorage.forRoot()],
  },
});

An example of using global storage in a module.

import {
  bootstrapNestApplication,
  createNestModule,
  DefaultNestApplicationInitializer,
  DefaultNestApplicationListener,
  InfrastructureMarkdownReportGenerator,
  InfrastructureMarkdownReportStorage,
  InfrastructureMarkdownReportStorageService,
} from '@nestjs-mod/common';
import { Injectable } from '@nestjs/common';

@Injectable()
class AppReportService {
  constructor(private readonly infrastructureMarkdownReportStorage: InfrastructureMarkdownReportStorageService) {}

  getReport() {
    return this.infrastructureMarkdownReportStorage.report;
  }
}

const { App1Module } = createNestModule({
  moduleName: 'App1Module',
  imports: [InfrastructureMarkdownReportStorage.forFeature()],
  providers: [AppReportService],
});

bootstrapNestApplication({
  modules: {
    infrastructure: [InfrastructureMarkdownReportStorage.forRoot(), InfrastructureMarkdownReportGenerator.forRoot()],
    system: [
      DefaultNestApplicationInitializer.forRoot(),
      DefaultNestApplicationListener.forRoot({
        staticConfiguration: {
          postListen: async ({ app }) => {
            if (app) {
              const appReportService = app.get(AppReportService);

              console.log(appReportService.getReport()); // # TestApp ...
            }
          },
        },
        staticEnvironments: { port: 3012 },
      }),
    ],
    feature: [App1Module.forRoot()],
  },
});

Shared providers​

InfrastructureMarkdownReportStorageService

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DefaultNestApplicationInitializer​

Default NestJS application initializer.

Use in NestJS-mod​

Use without options.

import { bootstrapNestApplication, DefaultNestApplicationInitializer } from '@nestjs-mod/common';

bootstrapNestApplication({
  modules: {
    system: [DefaultNestApplicationInitializer.forRoot()],
  },
});

Example of change cors options.

import { bootstrapNestApplication, DefaultNestApplicationInitializer } from '@nestjs-mod/common';

bootstrapNestApplication({
  modules: {
    system: [
      DefaultNestApplicationInitializer.forRoot({
        staticConfiguration: {
          cors: {
            origin: '*',
            methods: 'GET,HEAD,PUT,PATCH,POST,DELETE',
            preflightContinue: false,
            optionsSuccessStatus: 204,
          },
        },
      }),
    ],
  },
});

Static configuration​

KeyDescriptionConstraintsDefaultValue
corsCORS options from CORS packageoptional{"credentials":true,"methods":"GET,HEAD,PUT,PATCH,POST,DELETE"}-
bodyParserWhether to use underlying platform body parser.optional--
httpsOptionsSet of configurable HTTPS optionsoptional--
rawBodyWhether to register the raw request body on the request. Use req.rawBody.optional--
defaultLoggerDefault logger for applicationoptional--
loggerSpecifies the logger to use. Pass false to turn off logging.optional--
abortOnErrorWhether to abort the process on Error. By default, the process is exited. Pass false to override the default behavior. If false is passed, Nest will not exit the application and instead will rethrow the exception. @default trueoptional--
bufferLogsIf enabled, logs will be buffered until the "Logger#flush" method is called. @default falseoptional--
autoFlushLogsIf enabled, logs will be automatically flushed and buffer detached when application initialization process either completes or fails. @default trueoptional--
previewWhether to run application in the preview mode. In the preview mode, providers/controllers are not instantiated & resolved. @default falseoptional--
snapshotWhether to generate a serialized graph snapshot. @default falseoptional--
forceCloseConnectionsForce close open HTTP connections. Useful if restarting your application hangs due to keep-alive connections in the HTTP adapter.optionaltrue-

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DefaultNestApplicationListener​

Default NestJS application listener.

Use in NestJS-mod​

Use with manual environments and custom configuration.

import {
  bootstrapNestApplication,
  DefaultNestApplicationInitializer,
  DefaultNestApplicationListener,
  isInfrastructureMode,
} from '@nestjs-mod/common';
import { Logger } from '@nestjs/common';

bootstrapNestApplication({
  modules: {
    system: [
      DefaultNestApplicationInitializer.forRoot(),
      DefaultNestApplicationListener.forRoot({
        staticEnvironments: { port: 3000 },
        staticConfiguration: {
          mode: isInfrastructureMode() ? 'silent' : 'listen',
          preListen: async ({ app }) => {
            if (app) {
              app.setGlobalPrefix('api');
            }
          },
          postListen: async ({ current }) => {
            Logger.log(
              `🚀 Application is running on: http://${current.staticEnvironments?.hostname || 'localhost'}:${
                current.staticEnvironments?.port
              }/api`
            );
          },
        },
      }),
    ],
  },
});

Static environments​

KeyDescriptionSourcesConstraintsDefaultValue
portThe port on which to run the server.obj['port'], process.env['PORT']isNotEmpty (port should not be empty)--
hostnameHostname on which to listen for incoming packets.obj['hostname'], process.env['HOSTNAME']optional--

Static configuration​

KeyDescriptionConstraintsDefaultValue
modeMode of start application: init - for run NestJS life cycle, listen - for full start NestJS applicationoptionallisten-
preListenMethod for additional actions before listeningoptional--
postListenMethod for additional actions after listeningoptional--
defaultLoggerDefault logger for applicationoptional--
enableShutdownHooksEnable shutdown hooksoptionaltrue-
globalPrefixGlobal prefixoptionalapi-
logApplicationStartLog application startoptionaltrue-

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ProjectUtils​

Utilities for setting global application parameters, such as project name, description, and settings validation parameters.

Use in NestJS-mod​

Use with options.

import { DOT_ENV_FILE, PACKAGE_JSON_FILE, ProjectUtils, bootstrapNestApplication } from '@nestjs-mod/common';
import { join } from 'path';

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

bootstrapNestApplication({
  modules: {
    system: [
      ProjectUtils.forRoot({
        staticConfiguration: {
          applicationPackageJsonFile: join(appFolder, PACKAGE_JSON_FILE),
          packageJsonFile: join(rootFolder, PACKAGE_JSON_FILE),
          envFile: join(rootFolder, DOT_ENV_FILE),
        },
      }),
    ],
  },
});

An example of access to module services with forFeature.

import {
  DOT_ENV_FILE,
  DefaultNestApplicationInitializer,
  DefaultNestApplicationListener,
  DotEnvService,
  PACKAGE_JSON_FILE,
  ProjectUtils,
  bootstrapNestApplication,
  createNestModule,
} from '@nestjs-mod/common';
import { Injectable } from '@nestjs/common';
import { join } from 'path';

@Injectable()
class GetEnv {
  constructor(private readonly dotEnvService: DotEnvService) {}
  getEnv() {
    return this.dotEnvService.read();
  }

  getKeys() {
    return this.dotEnvService.keys(true);
  }
}
const { AppModule } = createNestModule({
  moduleName: 'AppModule',
  imports: [ProjectUtils.forFeature()],
  providers: [GetEnv],
});

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

process.env.TEST_APP_PORT = '2000';
process.env.TEST_APP_HOSTNAME = 'host';

bootstrapNestApplication({
  project: {
    name: 'test-app',
    description: 'Description for test-app',
  },
  globalEnvironmentsOptions: { debug: true },
  modules: {
    system: [
      ProjectUtils.forRoot({
        staticConfiguration: {
          applicationPackageJsonFile: join(appFolder, PACKAGE_JSON_FILE),
          envFile: join(rootFolder, DOT_ENV_FILE),
        },
      }),
      DefaultNestApplicationInitializer.forRoot(),
      DefaultNestApplicationListener.forRoot({
        staticConfiguration: {
          mode: 'silent',
          postListen: async ({ app }) => {
            if (app) {
              const getEnv = app.get(GetEnv);
              console.log(await getEnv.getEnv()); // output: { TEST_APP_PORT: '2000', TEST_APP_HOSTNAME: 'host' }
            }
          },
        },
      }),
    ],
    feature: [AppModule.forRoot()],
  },
});

When launched in the infrastructure documentation generation mode, the module creates an .env file with a list of all required variables, as well as an example example.env, where you can enter example variable values.

Shared providers​

WrapApplicationOptionsService, DotEnvService, PackageJsonService, ApplicationPackageJsonService, GitignoreService, NxProjectJsonService, ProjectUtilsPatcherService

Static configuration​

KeyDescriptionConstraintsDefaultValue
applicationPackageJsonFileApplication package.json-fileoptional--
packageJsonFileRoot package.json-fileoptional--
nxProjectJsonFileApplication project.json-file (nx)optional--
envFileDot-env file with environment variablesoptional--
updateEnvFileUpdate env-fileoptionaltrue-
updateProjectOptionsUpdate project propertiesoptionaltrue-
updateGlobalConfigurationAndEnvironmentsOptionsUpdate configuration and environments optionsoptionaltrue-

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License​

MIT