has is an array of has objects with the type, key and value properties.
missing is an array of missing objects with the type, key and value properties.
Redirects are checked before the filesystem which includes pages and /public files.
Redirects are not applied to client-side routing (Link, router.push), unless Middleware is present and matches the path.
When a redirect is applied, any query values provided in the request will be passed through to the redirect destination. For example, see the following redirect configuration:
 {
  source: '/old-blog/:path*',
  destination: '/blog/:path*',
  permanent: false
}
When /old-blog/post-1?hello=world is requested, the client will be redirected to /blog/post-1?hello=world.
Path Matching
Path matches are allowed, for example /old-blog/:slug will match /old-blog/hello-world (no nested paths):