feat: Mount non-dynamic routes first

[videah]

Description

Currently dynamic directory routes get mounted first which leads to other routes in the same directory never getting matched.

For example, when you have routes like routes/api/[id]/index.dart and routes/api/status.dart the latter can never get matched. The generated code will always mount the first route first so the router will always pass status to [id].

Additional Context

Here is the root handler generated by dart_frog with my current project which implements the Mastodon API. Routes for the second mount such as/api/v1/accounts/search can never be reached.

Handler buildRootHandler() {
  final pipeline = const Pipeline().addMiddleware(middleware.middleware);
  final router = Router()
    ..mount('/api/v1/accounts/<id>', (context,id,) => buildApiV1Accounts$idHandler(id,)(context))
    ..mount('/api/v1/accounts', (context) => buildApiV1AccountsHandler()(context))
    ..mount('/api/v1/timelines', (context) => buildApiV1TimelinesHandler()(context))
    ..mount('/api/v1', (context) => buildApiV1Handler()(context))
    ..mount('/oauth', (context) => buildOauthHandler()(context))
    ..mount('/', (context) => buildHandler()(context));
  return pipeline.addHandler(router);
}

[alestiago]

Hi @videah, thanks for opening this issue!

I haven't attempted to reproduce this yet. Regardless, would you possibly be interested in contributing with a PR?

[videah]

I would take a stab at it but I'm not entirely sure how I go about creating a local dev environment for dart_frog 😅

[alestiago]

I was able to reproduce this using dart_frog_cli version 0.3.6, see this for the full sample.

Demo video

https://github.com/VeryGoodOpenSource/dart_frog/assets/44524995/14ee63bb-5180-44b9-8146-a62f3dfd34d2

[alestiago]

For reference, we should definitely support this.

Here is a section of the OpenApi specification where the behaviour is mentioned.

[erickzanardo]

@videah unfortunately, changing the order of the mounting of the routes in such a proposed way will not be able at the moment.

We have spent time working on implementing a different order to make it possible for non-dynamic and dynamic routes that would listen to similar endpoint be able to respond to their specific urls, but we faced a couple of issues. We actually got the precedence to work as expected, but that generated complicated side effects for middlewares.

Since both GET routes/api/status and GET routes/api/XXXX would be able to handled from routes/api/[id]/index.dart and given the complications mentioned above we decided to keep as is and implement a conflict detection (#687), so at least, the developer will be notified of the conflict and issues will not go unnoticeable.

[erickzanardo]

Now that we have the validation in place, I will mark this as an enhancement so we can try to come back to it in there future after we had the code gen restructure.