Routing

A fast router built on web standards. Part of @b9g/router.

Router

import { Router } from "@b9g/router";
const router = new Router();

route(pattern: string, options?: RouteOptions): Route

Defines a route. Returns a Route object for chaining HTTP methods.

router.route("/users/:id").get(handler);
router.route("/posts/:id", { name: "post" }).get(handler);

use(middleware: Middleware): void

use(path: string, middleware: Middleware): void

Registers middleware globally or for a path prefix.

router.use(loggingMiddleware);
router.use("/api", authMiddleware);

mount(prefix: string, subrouter: Router): void

Mounts a subrouter at a path prefix.

router.mount("/api/v1", apiRouter);

handle(request: Request): Promise<Response>

Handles a request and returns a response.

const response = await router.handle(request);

match(url: string): RouteMatch | null

Tests if a URL matches any route.

const match = router.match("/users/123");
// { params: { id: "123" }, methods: ["GET"], pattern: "/users/:id" }

url(name: string, params: Record<string, string>): string

Generates a URL from a named route.

router.url("post", { id: "123" }); // "/posts/123"

Route

Returned by router.route(). Chain HTTP methods:

get(handler: Handler): Route

post(handler: Handler): Route

put(handler: Handler): Route

delete(handler: Handler): Route

patch(handler: Handler): Route

head(handler: Handler): Route

options(handler: Handler): Route

router.route("/users/:id")
  .get(getUser)
  .put(updateUser)
  .delete(deleteUser);

Handler

type Handler = (
  request: Request,
  context: RouteContext
) => Response | Promise<Response>;

RouteContext

interface RouteContext {
  params: Record<string, string>;
  // Plus properties added by middleware
}

Pattern Syntax

Pattern	Matches	Example
`/users`	Static path	`/users`
`/users/:id`	Named parameter	`/users/123` → `{ id: "123" }`
`/users/:id(\\d+)`	With constraint	`/users/123` (not `/users/abc`)
`/users/:id?`	Optional parameter	`/users`, `/users/123`
`/files/:path+`	One or more segments	`/files/a/b/c`
`/files/:path*`	Zero or more segments	`/files`, `/files/a/b`
`/files/*`	Wildcard	`/files/anything/here`

RouteOptions

Option	Type	Description
`name`	`string`	Name for URL generation

RouteMatch

Returned by router.match():

Property	Type	Description
`params`	`Record<string, string>`	Extracted parameters
`methods`	`string[]`	Registered HTTP methods
`pattern`	`string`	Matched pattern
`name`	`string \| undefined`	Route name if set

API