nestjs-util-restful

nestjs-util-restful

Description

Set of utils/helpers for restful nestjs setups.

---

• nestjs-util-restful
  • Description
  • Filter
    • GlobalExceptionFilter
    • BadRequestFilter
    • Extra
    • Formatter
    • Options
    • Example
  • Interceptor
  • InternalModule
  • Swagger
• Migration
  • Filter
  • InternalModule
  • Swagger
• Links

---

Filter

Hint: The ordering of the filter-provider is relevant (see full-example below)

These filter are for the api-server (and bg-task) only, in a microservice serve throw RpcException and let the nest default filter handle it.

GlobalExceptionFilter

The main filter that catches any error not yet processed.
Can be configured to push those errors to sentry too. (see Options)

BadRequestFilter

Catching BadRequestExceptions and prepare a response payload that supports the ValidationPipe errors.

Extra

• EntityNotFoundExtra: Catch typeorm entity-not-found error thrown when using .findOneOrFail()

This is not available as a filter itself, because of the optional typeorm dependency. Therefore, you must initialise the filter yourself:

import { EntityNotFoundError } from 'typeorm'
import { EntityNotFoundExtra } from '@diamir/nestjs-util-restful'
import { Catch } from '@nestjs/common'

@Catch(EntityNotFoundError)
class EntityNotFoundExceptionFilter extends EntityNotFoundExtra {}

Write your own custom filter by extending and implementing the AbstractExceptionFilter.

Formatter

Beside the basic application/json you can opt-in to return application/problem+json instead (or write your own formatter extending the abstract ErrorFormatter class).

import { ErrorFormatter, ProblemJsonFormatter } from '@diamir/nestjs-util-restful'
import { Module } from '@nestjs/common'

@Module({
  providers: [
    {
      provide: ErrorFormatter,
      useClass: ProblemJsonFormatter
    }
  ]
})

Options

You can customise the filter by providing an ERROR_OPTIONS object, to e.g. enable sentry for the GlobalExceptionFilter or disable logging for the BadRequestFilter

import { ERROR_OPTIONS } from '@diamir/nestjs-util-restful'
import { Module } from '@nestjs/common'

@Module({
  providers: [
    {
      provide: ERROR_OPTIONS,
      useValue: {
        GlobalExceptionFilter: {
          sentry: {
            enable: true,
            dsn: '...',
            environment: 'my-application'
          }
        },
        BadRequestFilter: {
          logging: false
        }
      }
    }
  ]
})

Example

import { rrorFormatter, ERROR_OPTIONS, GlobalExceptionFilter, BadRequestExceptionFilter, EntityNotFoundExceptionFilter, ProblemJsonFormatter } from '@diamir/nestjs-util-restful'
import { Module, ValidationPipe } from '@nestjs/common'
import { APP_FILTER, APP_PIPE } from '@nestjs/core'

@Module({
  providers: [
    {
      provide: ERROR_OPTIONS,
      useValue: {
        GlobalExceptionFilter: {
          sentry: {
            enable: true,
            dsn: '...',
            environment: 'my-application'
          }
        }
      }
    },
    {
      provide: ErrorFormatter,
      useClass: ProblemJsonFormatter
    },
    // filter are processed from bottom to top
    {
      provide: APP_FILTER,
      useClass: GlobalExceptionFilter
    },
    {
      provide: APP_FILTER,
      useClass: BadRequestExceptionFilter
    },
    {
      provide: APP_FILTER,
      useClass: EntityNotFoundExceptionFilter
    },
    // if an error occurs if passes 
    // 1. EntityNotFoundExceptionFilter
    // 2. BadRequestExceptionFilter
    // 3. GlobalExceptionFilter
    {
      provide: APP_PIPE,
      useClass: ValidationPipe
    }
  ]
})

Interceptor

• RequestProfilerInterceptor: logs incoming requests and how long they took until their response

import { Module } from '@nestjs/common'
import { APP_INTERCEPTOR } from '@nestjs/core'

import { RequestProfilerInterceptor } from '@diamir/nestjs-util-restful'

// restful server
@Module({
  providers: [
    {
      provide: APP_INTERCEPTOR,
      useClass: RequestProfilerInterceptor
    }
  ]
})

Example Output:

[2020-01-01T12:00:00.000Z] [debug] [RequestProfilerInterceptor] - GET /v1/hello/world starting
[2020-01-01T12:00:00.025Z] [debug] [RequestProfilerInterceptor] - GET /v1/hello/world finished - 200 - took: 0.0250 sec

InternalModule

Provides a controller with two GET endpoints

• GET /internal/status: provides status details as application-version and last-update date
• GET /internal/changelog: provides the changelog

@Module({
  imports: [
    InternalModule.forRoot({
      lastUpdateFile: ConfigService.get('misc.lastUpdateFile'), // path to the file from which the last-updated timestamp will be read
      changelogFile: ConfigService.get('misc.changelogFile'), // path to the changelog file
      includeLastUpdate: true // if the last-update timestamp should be processed or not
    })
  ]
})

Swagger

Set up the swagger documentation with a single function on application creation.

import { ConfigService } from '@diamir/nestjs-config'
import { SwaggerService } from '@diamir/nestjs-util-restful'

const app = await NestFactory.create(/* ... */)

SwaggerService.enable(app, {
  path: '/internal/docs',
  title: 'Swagger Docu',
  description: 'Some helpful description of the project'
}, {
  basePath: 'http://localhost:3000',
  apiPath: 'api'
})
// customise `DocumentBuilder`
SwaggerService.enable(app, ConfigService.get('swagger'), ConfigService.get('url'), {
  customize: (builder) => builder.addBearerAuth()
})

Migration

Filter

• replace dependency
• drop deprecated filter (server and microservice-server)
• replace with new filter

InternalModule

• replace dependency
• setup module with .forRoot() (see ConfigService paths in InternalModule)

Swagger

• replace dependency
• update SwaggerService.enable() to new syntax
  • old: enable(app, customize, swagger, url)
  • new: enable(app, swagger, url, customize) (see Swagger)

Links

• Diamir
• nestjs