[true (yada/as-resource nil)] gives me 404 status with default error page, [true (yada/as-resource (io/resource "asciinema/errors/404.html"))] gives me my custom error page but the status is 200

to get status 404 with custom page should I use sth like [true (yada/resource {:properties {:exists? false} :responses {404 {:response (fn [] ...)}}})]?

Yes

I guess I can also wrap the whole thing in a middleware

Not really. Ring middleware is synchronous

But you write something that wraps in a chain

But that's really what interceptors are doing

hmm, but I wouldn't be modifying the existing response (which could be manifold deferred in other cases indeed) , as in this case the whole response is nil

Ok

I know that ring middleware is not really compatible with yada in most cases (when it modifies the response), but in this case should be fine imo

Except for error scenarios

hmm, could you elaborate?

if there's no match for a bidi tree then aleph gets nil as a response

if you're happy that there's no change of any deferreds coming out of your yada interceptor chain, then it is safe

ah, I see

so you're trying to do

[true (yada/as-resource nil)]

yes

in which case, you can return a custom 404 page in your response function

so the middleware wrapping option would be when I don't have [true ...] in my bidi tree at all

(fn [ctx] (assoc (:response ctx) :status 404 :body "..."})

that will override the status to 404

you can write that resource once and use as a backstop in your bidi tree

I'm doing similary, yeah (I created my wrapper for yada/resource), but what I'm trying to solve now is the 404 on the routes level

so either [true (yada/resource {:produces "text/html" :response (fn [ctx] (assoc (:response ctx) :status 404 :body "..."})})] or wrapping bidi tree (coerced to handler) with a middleware which checks whether response is nil and then returns custom 404 error response

sounds fine to me

btw, if I want to report exceptions to external service (Bugsnag) I can safely do that from :logger fn, right?

Yes

I think others are doing something similar

thanks