README
Version Router Express
Lightweight api versioning tool for express
Installation
npm install --save version-router-express
import:
import {VersionRouter, VersionedRoute} from 'version-router-express';
This module generates Express middleware that enables efficient management of api routes versions. It enables the use of middleware arrays for each version of the route, and flexible version resolving strategies.
Usage
Determining the desired version for the request
VersionedRoute assumes the existence of a 'version' property on the request object. This property can be generated in any way along the route's path. VersionedRoute has a static utility method that can be mounted to extract the version from a header and assign it to req.version.
app.use(VersionedRouter.ExtractVersionFromHeader('App-version'));
Any custom header can be used, as well as any other strategy for assigning a value to request.version
Configuring versioned routes
Version matching is done according to semver standards.
const routeVersions = [
new VersionedRoute({
version: '1.0.0',
default: false,
middleware: [
(req: Request, res: Response, next: NextFunction) => {
console.log('route 2 function 1')
next()
},
(req: Request, res: Response, next: NextFunction) => {
console.log('route 2 function 2')
res.send({route: '1'})
},
]
}),
new VersionedRoute({
version: '>=1.2.0 <2.0.0',
default: false,
middleware: [
(req: Request, res: Response, next: NextFunction) => {
console.log('route 2 function 1')
next()
},
(req: Request, res: Response, next: NextFunction) => {
console.log('route 2 function 2')
res.send({route: '2'})
},
]
}),
new VersionedRoute({
version: '2.0.0',
default: true,
middleware: [
(req: Request, res: Response, next: NextFunction) => {
console.log('route 3 function 1')
next()
},
(req: Request, res: Response, next: NextFunction) => {
console.log('route 3 function 2')
res.send({route: '3'})
},
]
})
]
Request version is checked against the versioned route 'version' property according to the semver standard.
If no matches were found, it will resolve to the route defined as default.
Mount VersionRouter
app.use('/testRoute', new VersionRouter(routeVersions).routeRequestByVersion)
The router can be configured with a custom error handler for the version matching stage
app.use('/testRoute', new VersionRouter(
routeVersions,
{
errorHandler: (req, res, next) => {
// TODO do some error handling stuff
next(new Error('some message'))
}
}).routeRequestByVersion)
Api
Class: VersionRouter
Creates a router instance to route requests according to the value of req.version
export declare class VersionRouter
Constructors
Constructor | Description |
---|---|
constructor(routes, options) | Constructs a new instance of the VersionRouter class |
Properties
Property | Modifiers | Type | Description |
---|---|---|---|
errorHandler | (req: RequestWithVersion, res: Response, next: NextFunction) => void | Error handler function for the version matching stage | |
routes | Array<VersionedRoute> | Array of VersionedRoute defining the routing options and versions |
Methods
Method | Modifiers | Description |
---|---|---|
ExtractVersionFromHeaders(versionHeader) | static |
Middleware for extracting the version from the said request header and assign it to req.version Mount it once BEFORE all versioned routes |
routeRequestByVersion() | Middleware to mount on the route path e.g. app.use('/api/users', UsersRoutes.routeRequestByVersion()) |
Class: VersionedRoute
Creates a versioned route object that contains middleware and version data
Signature:
export declare class VersionedRoute implements VersionedMiddleware
Implements: VersionedMiddleware
Constructors
Constructor | Description |
---|---|
constructor(config) | Constructs a new instance of the VersionedRoute class |
Properties
Property | Modifiers | Type | Description |
---|---|---|---|
default | boolean | Sets the version as default.VersionRouter will resolve to the default route in when version property is undefined or no matching version was found |
|
middleware | Array<RequestHandler> | An array of request handlers to mount on the versioned route | |
version | string | Semver version number |
Methods
Method | Modifiers | Description |
---|---|---|
toRouter() | returns a Router instance with the route's middleware mounted |