composite-error


'composite-errors' allows you to wrap and re-throw an error, providing additional context without losing the original error information.

Overview

- You can wrap one or multiple errors into a CompositeError.
- You can use the CompositeError class as a base class for your own custom errors that can wrap other errors.
- The stack property of a CompositeError returns a string containing the stack trace of the CompositeError and the stack traces of the wrapped errors.

Installation

``
$ npm install --save composite-error
`

Usage

$3

`javascript
const CompositeError = require('composite-error');

try {
doSomething();
} catch (error) {
throw new CompositeError('Error occurred while trying to do something.', error);
}
`

$3

`javascript
throw new CompositeError('Multiple errors occurred', [error1, error2]);
`

$3

Using the ES2015 class syntax:

`javascript
class MyCustomError extends CompositeError {
constructor(message, innerErrors) {
super(message, innerErrors);
this.name = 'MyCustomError';
}
}
`

Not using the ES2015 class syntax:

`javascript
const util = require('util');

function MyCustomError(message, innerErrors) {
CompositeError.call(this, message, innerErrors);
this.name = 'MyCustomError';
}

util.inherits(MyCustomError, CompositeError);
`

$3

The stack property of a CompositeError returns a string containing the stack trace of the CompositeError and the stack traces of the wrapped errors.

For example, the following code

`javascript
const firstError = new Error('First error');
const secondError = new CompositeError('Second error', firstError);
const thirdError = new CompositeError('Third error', secondError);
console.log(thirdError.stack);
`

will produce the following output:

`
CompositeError: Third error
at Object. (/Users/nick/Projects/composite-error/example1.js:7:18)
at Module._compile (module.js:460:26)
at Object.Module._extensions..js (module.js:478:10)
[... snipped for brevity ...]
--- Inner error: CompositeError: Second error
at Object. (/Users/nick/Projects/composite-error/example1.js:6:19)
at Module._compile (module.js:460:26)
at Object.Module._extensions..js (module.js:478:10)
[... snipped for brevity ...]
--- Inner error: Error: First error
at Object. (/Users/nick/Projects/composite-error/example1.js:5:18)
at Module._compile (module.js:460:26)
at Object.Module._extensions..js (module.js:478:10)
[... snipped for brevity ...]
--- End of inner error
--- End of inner error
`

$3

The inner errors can be accessed using the CompositeError#innerErrors` property.

License

MIT