Error3 is an Error with extra powers. It has been designed to be extensible and easy to use. Though it has codes, message formatters and nested errors.
- Modern: designed for TypeScript and ES2019.
- IDE friendly: it's using classes and class fields to be inspectable for autosuggetion tools.
- i18n ready: formatter could produce localized messages with help of Intl API.
- Easy serialization and deserealization: good for network apps and JSON logging.
- Frontend caring: 0 dependencies, gzipped version is less then 1 KiB.
- It's easy to compare error codes using strict equality operator. What makes error handling robust.
- Codes could be used as part of URL. In documentation for example.
- Details are stored as primitives though they could be used to produce custom output, e.g. highlighting.
- Error message could be localized using Intl.
- Error message could be modified for environment purposes.
- Shorten error invocation code.
- It's network friendly. Error could be easy restored and represented on the client side using from code and details.
- In node.js:
npm i error3
- In browser:
CommonJS 路 UMD 路 ESM
<script src="https://unpkg.com/error3@3/dist/error3.min.js"></script>
鈿狅笍 Remember about security! Add subresource integrity (SRI) checksum from checksum.txt.
Error3 suppose that you will create some base error class for your application or library and then use it as a parent for all your errors. Watch example in examples folder. Here it is interface realization:
import Error3 from 'error3'
class NotFoundErr extends Error3 {
code = 'fs_not_found'
format({ filepath }) {
return `File "${filepath}" not found`
}
}
This is what it gives to us:
const error = new NotFoundErr({ filepath: './index.js' });
error.toString() // -> "NotFoundErr: [#fs_not_found] File "./index.js" not found"
error.message // -> "File "./index.js" not found"
error.code // -> fs_not_found
error.details // -> {filepath: './index.js'}
The same error TypeScript implementation:
import Error3 from 'error3'
class NotFoundErr extends Error3<{ filepath: string }, void> {
code = 'fs_not_found'
format({ filepath }): string {
return `File "${filepath}" not found`
}
}
Calling Error3#toJSON()
on Error3 instance returns an object with properties
code
, message
, details
, and errors
. Example output:
{
"code": "fs_not_found",
"message": "File \"./index.js\" not found",
"details": {
"filepath": "./index.js"
},
"errors": []
}
(details: object={}, errors: Error[]=[]) -> Error3
abstract. Both of Error3 constructor arguments are optional. The resposibility of
ancestor class is to implement proper interface and pass details
object
and errors
list into super()
call.
details
is using to describe error with JS primitives. Though it could be sent
via network to frontend, db, or ELK without extra parsing as it should be done
with regular Error instance.
abstract class Error3<Details, Errors> extends Error implements IError3 {
public readonly code: string|number
public readonly name: string
public readonly details: object
public readonly errors: Error[]
constructor(details: Details, errors: Errors) {}
abstract format(detials: Details, errors: Errors): string
}
const error = new UserMissed(
{userId: 1}, [new Error('Collection removed')]
);
error.code // -> user_missed
error.message // -> User #1 not loaded
error.details // -> {userId: 1}
error.errors // -> [Error('Collection removed')]
string|number
Error code should be a string or a number. It could be defined using class fields syntax:
class HttpNotFound extends HttpError {
code = 404
}
(details: object, errors: Error[]) -> string
abstract. Creates formatted message string from details and other errors.
This method is calling from Error3 constrcutor to define message
property.
class PortInUse extends Error3 {
format({ port }) {
return `Port ${port} is already in use`
}
}
class PortInUse extends Error3<{ port: string|number }, void> {
format({ port }): string {
return `Port ${port} is already in use`
}
}
Wrapper of Error3#valueOf
. It's created to be used by JSON.stringify()
.
() -> PlainError
This method realizes Object#valueOf()
behavior and returns plain error object containing properties:
code
, message
, details
and errors
.
{
code: string|number,
message: string,
details: object,
errors: PlainError[],
}
It is a result of Error3#valueOf()
call.
MIT 漏 Rumkin