typescript-router

A small and very typesafe router for TypeScript. Can be used with any client library/framework.

Route matching only occurs on the path portion of the url but query strings are all passed along (though multivalued query params aren't supported)

API

Create a new router

  // This is the validation library this router uses.
  import {string, number, isoDate} from 'idonttrustlikethat'
  import {Router, Route} from 'typescript-router'

  type UserId = string & { _tag: 'UserId' }
  const userId = string.tagged<UserId>()

  const router = Router(
    {
      index: Route('/'),
      users: Route('/users', object({ date: isoDate })),
      user: Route('/users/:id', object({ id: userId, q: number.optional() }))
    },
    { onNotFound }
  )

  function onNotFound(reason: string) {
    console.error(reason)
  }

Finding out the current Route

The route is synchronously available on the router, after its creation.
It is a type union discriminated by its name so you can use typescript to match and run behaviors based on that.

if (router.route.name === 'users') {
  doSomethingWithIt(router.route.params.date)
}

Subscribing to route changes

const unsubscribe = router.onChange(() => {
  console.log(router.route)
})

Update the route

Note: when using push, replace or link the params value types are converted to strings or numbers because the router needs to concatenate those in the url.
However, tagged strings keep their strong typing.

router.push('users', {date: '2020-12-22T17:31:58.337Z'})
// router.route is now {name: 'users', params: {date: Date}}

// Or
router.replace('users', {date: '2020-12-22T17:31:58.337Z'}))

Compute a link string ready to be used in anchors

const link = router.link('users', {date: '2020-12-22T17:31:58.337Z'})
// '/users?date=2020-12-22T17%3A31%3A58.337Z'

Use the Router types

Two helper types are exported:

The type of a given route params

import {RouteParams} from 'typescript-router'

type AppRouter = typeof router
type UserRouteParams = RouteParams<AppRouter, 'users'> // {date: Date}

The type of all route name + serializable params combinations, as a tuple

import {RouteAndParams} from 'typescript-router'

type AppRouter = typeof router
type AppRouteParams = RouteAndParams<AppRouter>

// Is the same type as:

type Tuples =
  | ['index', {}]
  | ['users', { date: string }]
  | ['user', { id: UserId; q?: number | undefined }]