express-auditor

Audit express requests and responses

Installation

Install this package in your NodeJS project

$ yarn add express-auditor

or

$ npm i express-auditor

Getting started

Creating a auditor instance

import express from 'express'
import { createAuditor } from 'express-auditor'

const app = express()

// create auditor and middleware instance
const { auditor, handler, errorHandler } = createAuditor(/* options */)

// setup the body/response types to auditor catch him
app.use(express.json())

// the handler object return is the express middleware
app.use(handler)

/*
  routes, middlewares, ...etc
*/

// put errorHandler after all definitions to catch uncaught exceptions in your routes
app.use(errorHandler)

app.listen(3000, () => console.log('app is running'))

Using audit in routes

The audit property is injected in all Request object

app.use('/', (request: Request, response: Response) => {
  // request.audit.doSomething

  /* do something */
})

By default two plugins are available

• request.audit.execution: this plugin is independent, he collect request, response, start time and and time data from each HTTP call
• request.audit.metadata: this plugin provide methods to make audit more rich
  • setUser(username): specify why user are execution request
  • setType(type): request action type, like 'CREATE_NEW_USER' to post filters
  • setDescription(description): Action description to post consume
  • addObject(object): string array, used to specify why objects the request is manipulating
  • addDetail(detail): string array, to provide details about actions, like 'Default permissions applied to new user'
  • addChange({ property, from, to }): object array, to register all changes from registered type in the object list

Call this methods are optional, but add rich data to post consume

Listening audited data

With auditor instance you can listen when response has sended to client

// Use this callback to save or show audited request
auditor.on('finish', (store) => {
  console.log(store)
  /*
    this go print in your terminal:
    {
      metadata: {
        executedAt: Date,
        objects: Array,
        details: Array,
        changes: Array
      },
      execution: {
        startAt: number,
        finishedAt: number,

        request: {
          body: object,
          method: string,
          url: string,
          params: object,
          query: object[],
          headers: object[],
          protocol: string,
          ip: string
        },

        response: {
          body: string,
          headers: object,
          statusCode: number,
          statusMessage: string
        },

        exception?: {
          name: string,
          message: string,
          stack: StackTrace[]
        }
      }
    }
  */
})

Options

In createAuditor you can pass the following options

Filter

Pass filter option to filter which requests/responses can be audited, if filter return false, audition is stopped and finish callback are not called

{
  filter: {
    request: {
      // HTTP verbs
      methods: ['GET', 'POST', 'PUT', 'DELETE']
    },

    response: {
      // 'Content-Type' header value
      contentType: ['application/json']
    }
  },
}

// OR

{
  filter: {
    request: (request: Request) => {
      /* ...some verification */
      
      return true
    },
    
    response: (response: Response) => {
      /* ...some verification */
      
      return true
    }
  }
}

Plugins

Pass plugins option you can add external/custom features do audition

{
  // Array with external/custom plugins
  plugins: [/* some plugins */],
}

Custom plugin example:

{
  plugins: [
    {
      // property name to be create in `request.audit` object
      name: 'name',

      create(req, res) {
        const store = {};

        return {
          // plugin state
          store,

          // injected actions in `request.audit.{name}` object
          plugin: {
            foobar() {
              // your can perform changes in state using plugin actions
              store.name = 'foobar'

              console.log('foobar')
            }
          },

          finish(store) {
            // store: root state of the audition

            // you can call actions using `this.plugin.foobar`
          }
        }
      }
    }
  ]
}

// now in all express route you can call `foobar()`

app.get('/', (request, response) => {
  request.audit.name.foobar() // 'foobar'

  response.send('o/')
})