Routing with @next/routing

You can use @next/routing to reproduce Next.js route matching behavior with data from onBuildComplete.

[!NOTE] @next/routing is experimental and will stabilize with the adapters API.

import { resolveRoutes } from '@next/routing'

const pathnames = [
  ...outputs.pages,
  ...outputs.pagesApi,
  ...outputs.appPages,
  ...outputs.appRoutes,
  ...outputs.staticFiles,
].map((output) => output.pathname)

const result = await resolveRoutes({
  url: new URL(requestUrl),
  buildId,
  basePath: config.basePath || '',
  i18n: config.i18n,
  headers: new Headers(requestHeaders),
  requestBody, // ReadableStream
  pathnames,
  routes: routing,
  invokeMiddleware: async (ctx) => {
    // platform-specific middleware invocation
    return {}
  },
})

if (result.resolvedPathname) {
  console.log('Resolved pathname:', result.resolvedPathname)
  console.log('Resolved query:', result.resolvedQuery)
  console.log('Invocation target:', result.invocationTarget)
}

resolveRoutes() returns:

• middlewareResponded: true when middleware already sent a response (the adapter should not invoke an entrypoint).
• externalRewrite: A URL when routing resolved to an external rewrite destination.
• redirect: An object with url (URL) and status when the request should be redirected.
• resolvedPathname: The route pathname selected by Next.js routing. For dynamic routes, this is the matched route template such as /blog/[slug].
• resolvedQuery: The final query after rewrites or middleware have added or replaced search params.
• invocationTarget: The concrete pathname and query to invoke for the matched route.
• resolvedHeaders: A Headers object containing any headers added or modified during routing.
• status: An HTTP status code set by routing (for example from a redirect or rewrite rule).
• routeMatches: A record of named matches extracted from dynamic route segments.

For example, if /blog/post-1?draft=1 matches /blog/[slug]?slug=post-1, resolvedPathname is /blog/[slug] while invocationTarget.pathname is /blog/post-1.