clojure - 如何使用 plumatic/schema 生成用户友好的验证消息？

Question

我希望能够为这些模式中的验证错误生成用户友好的或指定自定义错误消息:

(def Uuid (s/constrained String #(re-matches #"^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$" (name %))))
(def FirstName s/Str)
(def LastName s/Str)

(s/defschema Person {(s/required-key :id)         Uuid,
                     (s/required-key :first-name) FirstName,
                     (s/required-key :last-name)  LastName})

有效架构:

{
 :uuid "e143499c-1257-41e4-b951-c9e586994ff9" 
 :first-name "john" 
 :last-name "smith"
}

无效的架构:

{
 :uuid "" 
 :first-name nil 
 :last-name nil
}

无效的架构 - 错误:

{
 "id" : "(not (app.person/fn--4881 \"\"))",
 "first-name" : "(not (instance? java.lang.String nil))"
 "last-name" : "(not (instance? java.lang.String nil))"
}

我希望能够生成一些对非程序员来说更具可读性的东西，例如:

{
 "id" : "invalid uuid",
 "first-name" : "must be a string"
 "last-name" : "must be a string"
}

Answer 1

有趣的是，这正是几天前作为库发布的。

参见:

https://github.com/siilisolutions/humanize

首先，您还需要标记您的 Uuid 架构，以便稍后匹配它:

;; Note the last param I added: 
(def Uuid (sc/constrained
            String
            #(re-matches #"^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$"
                         (name %))
            'UUID))

(require '[schema.core :as sc]
         '[humanize.schema :as hs])

(#'hs/explain (sc/check Person {:id "foo"
                                :first-name "foo"
                                :last-name 3})
  (fn [x]
    (clojure.core.match/match
      x
      ['not ['UUID xx]]
      (str xx " is not a valid UUID")

      :else x)))

结果:

=> {:id "foo is not a valid UUID", :last-name "'3' is not a string but it should be."}

请注意，不幸的是，hs/explain 是私有(private)的，因此它需要一些小技巧。