ArityException when calling expound on a multi-spec with custom retag function

[kennyjwilli]

Take this example code:

(ns dev.expound
  (:require
    [clojure.spec.alpha :as s]
    [clojure.spec.gen.alpha :as gen]
    [expound.alpha :as expound]))

(defmulti bar-spec :type)

(s/def ::b string?)

(defmethod bar-spec ::b
  [_]
  (s/keys :req [::b]))

(s/def ::bar (s/multi-spec bar-spec (fn [val tag]
                                      (assoc val :type tag))))

I realize in this trivial example the retag function should be :type but for the sake of producing the error in more complex cases, I made it a function.

Running (expound/expound ::bar {}) produces this exception:

clojure.lang.ArityException: Wrong number of args (1) passed to: expound/fn--1994
	at clojure.lang.AFn.throwArity(AFn.java:429)
	at clojure.lang.AFn.invoke(AFn.java:32)
	at expound.alpha$no_method.invokeStatic(alpha.cljc:255)
	at expound.alpha$no_method.invoke(alpha.cljc:245)
	at expound.alpha$eval1720$fn__1721$fn__1722.invoke(alpha.cljc:396)
	at clojure.core$map$fn__5587.invoke(core.clj:2745)
	at clojure.lang.LazySeq.sval(LazySeq.java:40)
	at clojure.lang.LazySeq.seq(LazySeq.java:49)
	at clojure.lang.LazySeq.first(LazySeq.java:71)
	at clojure.lang.RT.first(RT.java:685)
	at clojure.core$first__5106.invokeStatic(core.clj:55)
	at clojure.string$join.invokeStatic(string.clj:180)
	at clojure.string$join.invoke(string.clj:180)
	at expound.alpha$eval1720$fn__1721.invoke(alpha.cljc:397)
	at clojure.lang.MultiFn.invoke(MultiFn.java:260)
	at expound.alpha$eval1730$fn__1731.invoke(alpha.cljc:411)
	at clojure.lang.MultiFn.invoke(MultiFn.java:260)
	at expound.alpha$print_explain_data$iter__1855__1859$fn__1860$fn__1861.invoke(alpha.cljc:704)
	at expound.alpha$print_explain_data$iter__1855__1859$fn__1860.invoke(alpha.cljc:702)
	at clojure.lang.LazySeq.sval(LazySeq.java:40)
	at clojure.lang.LazySeq.seq(LazySeq.java:49)
	at clojure.lang.RT.seq(RT.java:528)
	at clojure.core$seq__5124.invokeStatic(core.clj:137)
	at clojure.core$apply.invokeStatic(core.clj:652)
	at clojure.core$apply.invoke(core.clj:652)
	at expound.alpha$print_explain_data.invokeStatic(alpha.cljc:701)
	at expound.alpha$print_explain_data.invoke(alpha.cljc:687)
	at expound.alpha$printer_str.invokeStatic(alpha.cljc:842)
	at expound.alpha$printer_str.invoke(alpha.cljc:824)
	at expound.alpha$expound_str.invokeStatic(alpha.cljc:904)
	at expound.alpha$expound_str.invoke(alpha.cljc:896)
	at expound.alpha$expound.invokeStatic(alpha.cljc:917)
	at expound.alpha$expound.invoke(alpha.cljc:914)
	at dev.expound$eval2002.invokeStatic(form-init5270577758905363292.clj:1)
	at dev.expound$eval2002.invoke(form-init5270577758905363292.clj:1)
	at clojure.lang.Compiler.eval(Compiler.java:7062)
	at clojure.lang.Compiler.eval(Compiler.java:7025)
	at clojure.core$eval.invokeStatic(core.clj:3206)
	at clojure.core$eval.invoke(core.clj:3202)
	at clojure.main$repl$read_eval_print__8572$fn__8575.invoke(main.clj:243)
	at clojure.main$repl$read_eval_print__8572.invoke(main.clj:243)
	at clojure.main$repl$fn__8581.invoke(main.clj:261)
	at clojure.main$repl.invokeStatic(main.clj:261)
	at clojure.main$repl.doInvoke(main.clj:177)
	at clojure.lang.RestFn.invoke(RestFn.java:1523)
	at clojure.tools.nrepl.middleware.interruptible_eval$evaluate$fn__818.invoke(interruptible_eval.clj:87)
	at clojure.lang.AFn.applyToHelper(AFn.java:152)
	at clojure.lang.AFn.applyTo(AFn.java:144)
	at clojure.core$apply.invokeStatic(core.clj:657)
	at clojure.core$with_bindings_STAR_.invokeStatic(core.clj:1965)
	at clojure.core$with_bindings_STAR_.doInvoke(core.clj:1965)
	at clojure.lang.RestFn.invoke(RestFn.java:425)
	at clojure.tools.nrepl.middleware.interruptible_eval$evaluate.invokeStatic(interruptible_eval.clj:85)
	at clojure.tools.nrepl.middleware.interruptible_eval$evaluate.invoke(interruptible_eval.clj:55)
	at clojure.tools.nrepl.middleware.interruptible_eval$interruptible_eval$fn__863$fn__866.invoke(interruptible_eval.clj:222)
	at clojure.tools.nrepl.middleware.interruptible_eval$run_next$fn__858.invoke(interruptible_eval.clj:190)
	at clojure.lang.AFn.run(AFn.java:22)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

[bhb]

@kennyjwilli Thanks for reporting this! This is definitely a bug.

[bhb]

@kennyjwilli Thanks again for reporting this! This has been fixed as of e27059a and will be included in the next release.