Some helpers for better error handling in Node.js
npm install node-errors-helpersThis library helps with error handling in Node.
It provides following API:
- Generators API
- Custom error creation (with inheritance and chaining)
- Creates lists of errors from simple key-value objects
- Helpers API
- Getting iterable object from error instance
- Getting full name for inherited error instance
- Getting array of stacks for an error chain
- Detecting if there is an error of particular error class in the chain
Run npm install --save node-errors-helpers
Simple usage of this lib.
``javascript
const { createErrorClass, createErrorsList } = require('errors-helpers');
const SWError = createErrorClass(
'RuntimeError',
'Runtime error',
Error // parent error class, optional
);
const StarWarsErrors = createErrorsList({
'NO_LUKE': 'No Luke Skywalker!',
'NO_DARTH': 'No Darth Vader!',
'YOUR_FATHER': 'I am you father, Luke!',
}, SWError);
throw new SWError();
throw new StarWarsErrors.YOUR_FATHER({ location: 'Bespin' });
throw new StarWarsErrors.NO_LUKE({ far: 'away' }, causedByError / some generated or catched error /);
`
* helpers
* .getFullName(error) ⇒
* .getObject(error) ⇒
* .getFullStack(error) ⇒
* .hasErrorClass(error, ErrorClass) ⇒ $3
Creates error class with the
provided, that will throw error with message. When baseType class provided, new error class will be extending base one, if not Error class is extended. Each error generated with this helper will have specific structure and constructor.Returns:
CustomError| Param | Type | Description | Optional |
| --- | --- | --- | --- |
| name |
| Name the for class to generate. | no |
| message | String | The message calss instance will be thrown with. | no |
| baseType | String | Class to extend. If not provided Error class is extended. | yes |Any custom error has such constructor:
`javascript
const err = new CustomError(data = null, causedBy = null);
// err.data
// err.name
// err.causedBy
` provided in class constructor.
Field data has any type. So you can pass there everything.You can pass an error as second param and it will be saved as cause of current error. See examples for more information.
$3
Generates object of errors from object of definitions.
If no extend class provided error classes are extended from Error.Object sample:
`javascript
{
'SOME_ERROR_CODE': 'Message that will be shown.',
'ANOTHER_ERROR': 'Another message %)'
}
`
Returns: | Param | Type | Description | Optional |
| --- | --- | --- | --- |
| list |
| Object that define errors. | no |
| extend | AnyErrorType | Class that all generated errors will extend. | yes |$3
Returns full name of error. Concats all parent classes names with
..Returns:
String| Param | Type | Description | Optional |
| --- | --- | --- | --- |
| error |
| CustomError | no |$3
Retruns iterable error data object.
For better errors representation in JSON format.
Returns:
Object { name, stack, message, data, causedBy }| Param | Type | Description | Optional |
| --- | --- | --- | --- |
| error |
| CustomError | no |$3
Recursively gets stacks from
causedBy errors and return Array of them.Returns:
Array\| Param | Type | Description | Optional |
| --- | --- | --- | --- |
| error |
| CustomError | no |$3
Looks for
ErrorClass in error. Recursivly looks in causedBy fields.
Returns true if an instance of ErrorClass is found, false otherwise.
Returns:
Boolean| Param | Type | Description | Optional |
| --- | --- | --- | --- |
| error |
| Where to look for class. | no |
| ErrorClass | AnotherCustomError` | What class to look for. | no |