DRAFT: adds flow options to basic Router, as well as custom option/object passthrough

[kwhitley]

Description

This adds support for passthrough options (e.g. port in a Bun service), as well as the following specific options:

• after: what you would pass to a .then() chain on the router.handle/router.fetch.
• errors: what you would pass to a catch block. if not defined, Router will still throw (uncaught).

Adds appx. 45 bytes.

Considerations

The bulk of the bytes added is to support the explicit try/catch block (and rethrow). If we did not support errors in this, it would be closer to 460 bytes total (instead of 490).

Example Usage

import { Router, RouterType, error, json, withParams } from '../src/index'

const router = Router({
  port: 3000,
  after: json,
  error: error, // long form for clarity
})

router
  .get('/json', () => ({ foo: 'bar' }))
  .get('/throw', (a) => a.b.c) // this is caught!
  .all('*', () => error(404))

export default router

Type of Change (select one and follow subtasks)

• Documentation (README.md)
• Maintenance or repo-level work (e.g. linting, build, tests, refactoring, etc.)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
  • I have included test coverage
• Breaking change (fix or feature that would cause existing functionality/userland code to not work as expected)
  • Explain why a breaking change is necessary:
• This change requires (or is) a documentation update
  • I have added necessary local documentation (if appropriate)
  • I have added necessary itty.dev documentation (if appropriate)

[kwhitley]

I think this one will be killed in favor of AutoRouter. It makes sense to keep the core as minimalist as possible for use-cases that demand it, while allowing AutoRouter to be the batteries-included version for tiny demos.

[kwhitley]

Killed in favor of #222