I added this issue comment earlier https://github.com/metosin/reitit/issues/145#issuecomment-424610485 but I’m starting to suspect it deserves its own issue. Unfortunately I have no idea how to reproduce…

tl;dr there’s something weird happening with data-specs. Reading the code, I have no idea how a reitit :parameters definition can turn into a spec for which (ifn? spec) is false.

It’s still pretty probable I’ve just misunderstood something and this is my fault 🙂

@hannu.hartikainen parameters are turned to specs via IntoSpec protocol: https://github.com/metosin/reitit/blob/master/modules/reitit-spec/src/reitit/coercion/spec.cljc

I tried changing to normal specs (instead of data specs) and still get the same error. And it still works on my machine. Hmm.

I think you basically get Can't invoke spec with a non-function predicate when you call the output of (ds/spec my-map) directly.

Still can’t figure out how a different build environment could cause that to happen.

@hannu.hartikainen you shoudn’t call the spec directly, but to use it like a spec instead:

(require '[spec-tools.data-spec :as ds])
(require '[spec-tools.core :as st])

(def spec (ds/spec ::kikka {:x int?}))

(spec {:x 1})
; CompilerException clojure.lang.ExceptionInfo: Can't invoke spec with a non-function predicate

(st/decode spec {:x 1})
; {:x 1}

(st/decode spec {:x "1"})
; :clojure.spec.alpha/invalid

(st/decode spec {:x "1"} st/string-transformer)
; {:x 1}

for predicates, it can be invoked directly, so (st/spec int?) can be used like int?, but that’s kinda bonus, not an intented way. wondering if the invoking should be removed to avoid confusion…

My code doesn't invoke specs though. I just use the reitit coercion middleware, and that somehow causes a spec record to be invoked.

@hannu.hartikainen could you provide a small failing sample Repo?

I'll come back to you if I find a way to do that. As I said, the uberjar works just fine except when built on our Jenkins server...

Basically if I don't get any ideas about what might be the issue, I won't have time to do it. The build+deploy cycle is slow enough that I've been already trying to find any workaround to avoid investigating this further (current idea: just don't use coercion middleware when built in CI).