NError

Nested Error ES6 class

Installation

``
npm install --save nerror
`

Usage

An abstract example

`javascript
const NError = require('nerror');

try {
try {
try {
let error = new Error('Some DB error');
error.code = 42000;
throw error;
} catch (error) {
throw new NError(error, { sqlState: error.code }, 'Could not insert row');
}
} catch (error) {
throw new NError(error, { customerId: 9000 }, 'Could not create user');
}
} catch (error) {
console.log(error.messages, JSON.stringify(error.info, undefined, 4));
/* Could not create user: Could not insert row: Some DB error {
"sqlState": 42000,
"customerId": 9000
} */

console.log(error.fullStack);
/* NError: Could not create user
at Object. (/home/ross/tmp/nerror/test.js:13:15)
at Module._compile (module.js:570:32)
at Object.Module._extensions..js (module.js:579:10)
at Module.load (module.js:487:32)
at tryModuleLoad (module.js:446:12)
at Function.Module._load (module.js:438:3)
at Module.runMain (module.js:604:10)
at run (bootstrap_node.js:393:7)
at startup (bootstrap_node.js:150:9)
at bootstrap_node.js:508:3
NError: Could not insert row
at Object. (/home/ross/tmp/nerror/test.js:10:19)
at Module._compile (module.js:570:32)
at Object.Module._extensions..js (module.js:579:10)
at Module.load (module.js:487:32)
at tryModuleLoad (module.js:446:12)
at Function.Module._load (module.js:438:3)
at Module.runMain (module.js:604:10)
at run (bootstrap_node.js:393:7)
at startup (bootstrap_node.js:150:9)
at bootstrap_node.js:508:3
Error: Some DB error
at Object. (/home/ross/tmp/nerror/test.js:6:25)
at Module._compile (module.js:570:32)
at Object.Module._extensions..js (module.js:579:10)
at Module.load (module.js:487:32)
at tryModuleLoad (module.js:446:12)
at Function.Module._load (module.js:438:3)
at Module.runMain (module.js:604:10)
at run (bootstrap_node.js:393:7)
at startup (bootstrap_node.js:150:9)
at bootstrap_node.js:508:3 */
}
`

NError

$3

parent is optional parent error instance

info is optional information attached to the error. it will be merged with parents' info objects

...args - rest is usual Error constructor arguments

#### Examples

The following are all valid constructor calls:

* new NError('Error occurred') // just like usual Error

* new NError(new Error('Test'), 'Error occurred') // pass the parent

* new NError({ someKey: "some value" }, 'Error occurred') // pass info

* new NError(new NError('Some error'), { key: 'value' }, 'Error occurred') // do both

$3

Parent error accessor

$3

Combined information created by merging infos of all the parent chain

$3

Combined messages of all the parents

$3

Combined stack info of all the parents

$3

Convert this error chain to an array. Consider the following example:
`
let err1 = new Error('1');
let err2 = new NError(err1, '2');
let err3 = new NError(err2, '3');
`
err3.toArray() will return: [ err3, err2, err1 ]`