A fast pattern router.

Usage

A subset of URLPattern API patterns are supported.

import { router_init, router_set, router_remove } from '@mapl/pattern-router';
import { router_compile_to_matcher } from '@mapl/pattern-router/match';

const router = router_init<(req: Request) => Response | Promise<Response>>();
router_set(router, 'GET', '/', (req) => new Response('Hi'));
router_set(router, 'GET', '/user/:id(\\d+)', (req, params) => new Response(`user id: ${params.id}`));
router_set(router, 'PUT', '/post/:id(\\d+)', (req, params) => updatePost(req, params.id));
router_remove(router, 'GET', '/user/:id(\\d+)');

const matcher = router_compile_to_matcher(router);
matcher.match('GET', '/'); // [(req) => new Response('Hi')]
matcher.match('GET', '/user/001'); // undefined
matcher.match('PUT', '/post/001'); // [(req, params) => updatePost(req, params.id), { id: '001' }]
matcher.match('PUT', '/post/a01'); // undefined

Limitations

Wildcards and unnamed capture groups don't capture. Use named capture groups instead:

router_set(router, 'GET', '/(\\d+)', ...);
// change to
router_set(router, 'GET', '/:id(\\d+)', ...);
// or without automatic group prefixing
router_set(router, 'GET', '{/:id(\\d+)}', ...);

Named groups only capture the last matched value in group delimiters with + and * modifier.

router_set(router, 'GET', '/post{/:id}+', ...); // '/post/a/b' -> { id: 'b' }

JIT

To wrap compiled code pieces with routing code:

import { router_init, router_set, router_remove } from '@mapl/pattern-router';
import { router_compile_to_code } from '@mapl/pattern-router/jit';

const router = router_init<string>();
router_set(router, 'GET', '/', 'return "Home"');
router_set(router, 'POST', '/forum/:forum+', 'return "Posting to " + matchedResult.groups.forum'); // access matched params

const match = (0, eval)(`(method, path) => {${router_compile_to_code(router, 'matchedResult', 'path', 'method')}}`);

match('GET', '/'); // "Home"
match('GET', '/about'); // undefined
match('POST', '/forum/@mapl/pattern-router'); // "Posting to @mapl/pattern-router"

Types

To infer parameters types of a pattern:

import type { InferParams } from '@mapl/pattern-router/tree/utils';

type T = InferParams<'/:id'>; // { id: string }
type T = InferParams<'/user/:id?'>; // { id: string | undefined }
type T = InferParams<'/book{s/:id}?'>; // { id: string | undefined }

Compability

This library requires RegExp.escape() and duplicate named capture groups in different disjunction feature support.