Ex-Error

An extendible error class for creating custom error.

Why Use This Package?

Custom error object is quite useful if you need to filter specific error type. You can read this article to get more context why custom error is very useful.

Example:

1// With standard error object
2try {
3  // Normally one will throw an error
4  throw new Error('Error on auth');
5} catch (err) {
6  // catch error in here
7}
8
9// With custom error object
10try {
11  throw new AuthError('Your password is missing');
12} catch (err) {
13  if (err instanceof AuthError) {
14    // process error for AuthError
15  } else {
16    // process error for other than AuthError
17  }
18}

Using Package

1import exError from 'ex-error';
2// or
3const exError = require('ex-error');
4
5// creating default error object from standard Error class
6const DefaultError = exError();
7
8try {
9  // adding error message
10  throw new DefaultError('Error using default error');
11} catch (e) {
12  console.log(e.message); // -> 'Error using default error'
13  console.log(e.name); // -> 'Error'
14  console.log(e instanceof DefaultError); // -> true
15}
16
17// creating custom error object
18const CustomError = exError('CustomError');
19
20try {
21  // adding error message and custom properties
22  throw new CustomError('Custom error', {
23    code: 500,
24    otherMessage: 'other message'
25  });
26} catch (e) {
27  console.log(e.message); // -> 'Custom error'
28  console.log(e.name); // -> 'CustomError'
29  console.log(e instanceof CustomError); // -> true
30  console.log(e.code); // -> 500
31  console.log(e.otherMessage); // -> 'other message'
32}

One can also use it as class extension

1import exError from 'ex-error';
2
3const CustomError = exError('CustomError');
4
5class UseCustomError extends CustomError {}
6
7try {
8  // adding error message and custom properties
9  throw new UseCustomError('Custom error', {
10    code: 500,
11    otherMessage: 'other message'
12  });
13} catch (e) {
14  console.log(e.message); // -> 'Custom error'
15  console.log(e.name); // -> 'CustomError'
16  console.log(e instanceof CustomError); // -> true
17  console.log(e.code); // -> 500
18  console.log(e.otherMessage); // -> 'other message'
19}

License

Licensed under the MIT License. You can find a copy of it in LICENSE.