RegExpRouter

Kind: Class

Source: src/router/reg-exp-router/router.ts

Part of: Router

RegExpRouter stores method and path registrations, then builds regular-expression matchers for route lookup. It is a router implementation used by the application to map incoming request paths to registered handlers.

Implements: Router

Methods

Properties

Where it refuses work

• RegExpRouter stops the work with Error when !middleware || !routes.

When something fails

• RegExpRouter handles failure in 1 place: it lets it reach the caller in all 1.

Diagram

mermaid
graph LR
  App[Application] --> Add[add()]
  Add --> Insert["#insertPath()"]
  Insert --> Routes[Route definitions]
  Routes --> BuildAll["buildAllMatchers()"]
  BuildAll --> Build["#buildMatcher()"]
  Build --> Matchers["MatcherMap<T>"]

Usage

ts
import { Hono } from 'hono'
import { RegExpRouter } from 'hono/router/reg-exp-router'

const router = new RegExpRouter()
const app = new Hono({ router })

app.get('/users/:id', (c) => {
  return c.json({
    id: c.req.param('id'),
  })
})

app.post('/users', async (c) => {
  const body = await c.req.json()
  return c.json(body)
})

export default app

AI Coding Instructions

• Register routes through add() or the application routing API; do not call private methods such as #insertPath() directly.
• Keep route method and path patterns consistent, since matcher generation groups routes by HTTP method.
• Update #buildMatcher() when changing how path parameters or route patterns are translated into regular expressions.
• Preserve the MatcherMap<T> contract when modifying buildAllMatchers(), because request matching depends on its generated matchers.

Relationships

• IMPORTS → MESSAGE_MATCHER_IS_ALREADY_BUILT
• IMPORTS → METHOD_NAME_ALL
• IMPORTS → UnsupportedPathError
• IMPORTS → checkOptionalParameter
• IMPORTS → match
• IMPORTS → emptyParam
• IMPORTS → PATH_ERROR
• IMPORTS → Trie

Used by

1 reference from 1 file. Each is a place in this repository where the symbol is actually used — go read one rather than trusting an example.

Imported by (1)

• PreparedRegExpRouter — src/router/reg-exp-router/prepared-router.ts:9