@reflet/http
v1.0.0
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Low-level TypeScript HTTP-related modules
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@reflet/http
🌠
Ultra typed, (over) documented, and neatly organised HTTP primitives. Built with a simple and discoverable API surface, for a great developper experience.
Getting started
Requires at least typescript 4.0.
npm i @reflet/http
Status 🎰
Ultra typed, over documented, and neatly organised HTTP status enums, to use for a great developper experience.
Usage
import { Status } from '@reflet/http'
res.sendStatus(Status.Created)
Enums
Status
enum has every status and also the following sub enums:
Information
for 1xx responses.Success
for 2xx responses.Redirection
for 3xx responses.ClientError
for 4xx responses.ServerError
for 5xx responses.Error
for 4xx and 5xx responses.
import { Status, HttpError } from '@reflet/http'
throw HttpError(Status.ClientError.Forbidden)
These enums are actually object litterals with a const
assertion.`
Unions
When use as a type, each category is a union of corresponding status codes.
import { Status } from '@reflet/http'
function redirect(status: Status.Redirection, url: string) {
// ...
}
Header 📰
Usage
import { Header } from '@reflet/http'
const type = req.header(Header.ContentType)
Enums
Header
enum is composed of the following exported enums:
RequestHeader
for the HTTP request headers.ResponseHeader
for the HTTP response headers.
import { RequestHeader, ResponseHeader } from '@reflet/http'
req.get(RequestHeader.XForwardedFor)
res.set(ResponseHeader.Allow, 'GET')
These enums are actually object litterals with a const
assertion.`
Unions
When use as a type, each category is a union of corresponding headers.
import { Header, ResponseHeader } from '@reflet/http'
function setHeader(name: ResponseHeader, value: string) {
//...
}
Augmentations
If your application has custom headers, you can augment the union type (but not directly the enum value)
with the dedicated global namespace RefletHttp
:
declare global {
namespace RefletHttp {
interface RequestHeader {
XCustom: 'x-custom'
}
interface ResponseHeader {
XCustom: 'x-custom'
}
}
}
HttpError 💢
Usage
import { HttpError } from '@reflet/http'
throw HttpError(400)
throw HttpError(500, 'My bad')
Attached properties
status
The resulting error has a status
property that will be used, for example by Express and Fastify error handlers, to properly set the HTTP response status.
name
The resulting error name
property will be inferred from status
: e.g. "NotFound" for 404.
If you use a unknown error status code, the error name
will be "HttpError".
Need more?
Have a look at the Augmentations section.
Enumerability
To respect the inherited Error
, non-enumerable properties are kept non-enumerable: name
, message
, stack
.They won't be serialized by JSON.stringify
(MDN reference).
Dedicated static methods
Instead of passing the status code, the known HTTP errors are exposed as static methods: List of HTTP errors.
throw HttpError.Unauthorized('Get out')
// HttpError { status: 400, name: 'Unauthorized', message: 'Get out' }
throw HttpError.InternalServerError('My bad')
// HttpError { status: 500, name: 'InternalServerError', message: 'My bad' }
Optional new
keyword
You can instantiate HttpError
with or without the new
keyword, just like the built-in Error
constructor.
throw HttpError(401)
The compiler is okay with both. 👌
Augmentations
By default, the only parameter you can pass besides the status code is message?: string
. You might want your error objects to have more details.
The global namespace RefletHttp
gives the possibility, for each different status, to change the optional message
parameter to a required data
object parameter. This object's properties will be attached to the resulting error (at runtime and compile time).
export {} // necessary to be in a module file
declare global {
namespace RefletHttp {
interface Forbidden {
access: 'read' | 'create' | 'update' | 'delete'
target: string
}
// Could be useful for custom headers since frameworks usually set the response headers with the error headers property:
interface MethodNotAllowed {
headers: {
allow: ('GET' | 'POST' | 'PUT' | 'PATCH' | 'DELETE')[]
}
}
}
}
throw new HttpError(403, { access: 'read', target: 'user' })
// HttpError { status: 400, name: 'Forbidden', access: 'read', target: 'user' }
throw HttpError.MethodNotAllowed({ headers: { allow: ['GET'] } })
// HttpError { status: 505, name: 'MethodNotAllowed', headers: { allow: ['GET'] } }
Every known HTTP error is available for augmentation under its own name: List of HTTP errors.
Custom Errors
Use both the CustomErrors
interface and the defineCustomErrors
function to create new static methods associated with their status.
declare global {
namespace RefletHttp {
interface CustomErrors {
299: 'Aborted'
420: 'EnhanceYourCalm'
}
}
}
// You must define the new errors at runtime, in order for the static methods to exist.
defineCustomErrors({ 299: 'Aborted', 420: 'EnhanceYourCalm' })
Constraints
With the ErrorConstraint
interface, you can whitelist the errors you application uses.
declare global {
namespace RefletHttp {
interface ErrorConstraint {
status: 400 | 401 | 403 | 404 | 405 | 422 | 500
// or widen to all numbers with `status: number`
}
}
}
message
property stringification
If you define a message
property with different type than string
, like so:
declare global {
namespace RefletHttp {
interface BadRequest {
message: Record<string, any>
}
}
}
it will always be stringified to respect the original Error
interface (at runtime and compile time).
So:
throw HttpError(400, { message: { about: 'thing' } })
gives the following stack trace:
BadRequest: {"about":"thing"} # instead of "BadRequest: [Object object]"
at ...
Protections
Since these augmentations affect the error object itself, you cannot define the following properties:
name
, status
, stack
, __proto__
, constructor
, prototype
.
List of HTTP errors
| Status | Name |
|--------|---------------------------------|
| 400
| BadRequest
|
| 401
| Unauthorized
|
| 402
| PaymentRequired
|
| 403
| Forbidden
|
| 404
| NotFound
|
| 405
| MethodNotAllowed
|
| 406
| NotAcceptable
|
| 407
| ProxyAuthenticationRequired
|
| 408
| RequestTimeout
|
| 409
| Conflict
|
| 410
| Gone
|
| 411
| LengthRequired
|
| 412
| PreconditionFailed
|
| 413
| PayloadTooLarge
|
| 414
| URITooLong
|
| 415
| UnsupportedMediaType
|
| 416
| RequestedRangeNotSatisfiable
|
| 417
| ExpectationFailed
|
| 418
| ImATeapot
|
| 421
| MisdirectedRequest
|
| 422
| UnprocessableEntity
|
| 423
| Locked
|
| 424
| FailedDependency
|
| 425
| UnorderedCollection
|
| 426
| UpgradeRequired
|
| 428
| PreconditionRequired
|
| 429
| TooManyRequests
|
| 431
| RequestHeaderFieldsTooLarge
|
| 451
| UnavailableForLegalReasons
|
| 500
| InternalServerError
|
| 501
| NotImplemented
|
| 502
| BadGateway
|
| 503
| ServiceUnavailable
|
| 504
| GatewayTimeout
|
| 505
| HTTPVersionNotSupported
|
| 506
| VariantAlsoNegotiates
|
| 507
| InsufficientStorage
|
| 508
| LoopDetected
|
| 509
| BandwidthLimitExceeded
|
| 510
| NotExtended
|
| 511
| NetworkAuthenticationRequired
|