sharp-error-handler

Sharp-Error-Handler

A NodeJS module that integrates with HapiJS Server Framework & uses Boom to return custom error messages, error codes & custom error fields.

First define a json object containing where the key is the error name, value is an object containing the required statusCode & message (you may use also use extraFields

 
{
    "invalidId": {
        "statusCode": 400,
        "message": "This Id is invalid"
    },
    
    "notAuthorized": {
        "statusCode": 403,
        "message": "You're not authorized to access this item"
    }
}

Then create your custom error objects

 
const errorHandler = require('sharp-error-handler');
const ServerErrors = errorHandler.createServerErrors(errorsData);

Then inside your code

 
throw new ServerErrors.InvalidId();

and in the catch function

 
catch(error) {
    return errorHandler.wrapError(null, error);
}

This makes Hapi Server returns

 
{
    "statusCode": 400,
    "message": "This Id is invalid",
    "error": "Bad Request Error"
}

Features

• wrapError function takes two arguments, the first is a log class & the second is the error object itself. the module calls the log function of the first argument, this is helpful if your server uses a default logging library like winston. You can also provide the console class

• Some modules use logging with tag, example

   
  class.log(tag, message)

  Then you can use the other function which is wrapErrorWithTag which takes three arguments. loggerClass, tag, error

• The arrangement of arguments is made this way to facilitate the usage of curry functions.

• a flag called isCreatedServerError is added on the error object if the user needs to know whether the error was thrown on purpose or not

   
  const wrappedError = errorHandler.wrapError(null, error);
  console.log(wrappedError.isCreatedServerError); //true if the error was created by errorHandler.createServerErrors

• Error names are defaulted to first letter capital example: if errors.json is

   
  {
      "invalidId": {
          "statusCode": 400,
          "message": "This Id is invalid"
      }
  }

  Then the error will to throw will be

   
  ServerErrors.InvalidId()

• If data is provided in the constructor object of the error it will be added by default to the error message example: if errors.json is

   
  {
      "invalidId": {
          "statusCode": 400,
          "message": "This Id is invalid: "
      }
  }

  and the error is

   
  throw new ServerErrors.InvalidId("122");

  The message returned will be

  
  "This Id is invalid: 122"
  

extraFields:

• adds all keyValue pairs written inside it to the default output object of Hapi

• must be an object

• example:

  errors.json

   
  {
      "invalidId": {
          "statusCode": 400,
          "message": "This Id is invalid",
          "extraFields": {
              "ERROR_CODE": 112
          }
      }
  }

  Hapi final result will be

   
  {
      "statusCode": 400,
      "message": "This Id is invalid",
      "error": "Bad Request Error",
      "ERROR_CODE": 112
  }