[spec] s/& does not check preds if regex matches empty collection


  • Type: Defect Defect
  • Status: Open Open
  • Priority: Critical Critical
  • Resolution: Unresolved
  • Affects Version/s: Release 1.9
  • Fix Version/s: Release 1.10
  • Component/s: None
  • Labels:
  • Patch:
    Code and Test
  • Approval:


In the following example, the ::x key is required in the map but it will conform without error for an empty collection:

(s/def ::x integer?)
(s/conform (s/keys* :req-un [::x]) [])
;; nil, expected error
(s/explain (s/keys* :req-un [::x]) [])
;; Success!, expected explanation

Cause: At the moment, (s/keys* :req-un [::x]) is expanded to a form equivalent to the following one:

(s/& (s/* (s/cat ::s/k keyword? ::s/v))
     (s/keys :req-un [::x]))

The issue seems to be in the implementation of s/&, specifically the ::amp branch of accept-nil? which expects that either the conformed regex returns empty or that the preds are not invalid. This seems like a false assumption that an empty conformed regex ret does not require the s/& preds to be valid. In this case we are using a conformer to transform the input and do another check, so it's certainly not valid here.

Proposed: Modify s/& to always validate the preds when accepting nil.

user=> (s/conform (s/keys* :req-un [::x]) [])

user=> (-> (s/explain-data (s/keys* :req-un [::x]) []) ::s/problems first :pred)
(clojure.core/fn [%] (clojure.core/contains? % :x))

Patch: clj-2182-2.patch

Screened by: Stu Halloway

  1. clj-2182.patch
    13/Jun/17 8:42 AM
    1 kB
    Alex Miller
  2. clj-2182-2.patch
    29/Jun/17 4:20 PM
    3 kB
    Alex Miller


Alex Miller added a comment -

-2 patch includes a test

Alex Miller added a comment - -2 patch includes a test


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