Schema-tools 
Common utilities for Prismatic Schema for Clojure/Script. Big sister to spec-tools.
- common Schema definitions:
any-keys,any-keyword-keys,open-schema,optional-keys-schema - schema-aware selectors:
get-in,select-keys,select-schema - schema-aware transformers:
assoc,dissoc,assoc-in,update-in,update,dissoc-in,merge,optional-keys,required-keys- removes the schema name and ns if the schema (value) has changed.
- handle schema default values via
default&default-coercion-matcher - meta-data helpers:
schema-with-descriptionschema-description,resolve-schema(clj only),resolve-schema-description(clj only) - coercion tools:
or-matcher,map-filter-matcher,multi-matcher,coercer,coerce - tuned JSON & String matchers: from keywords, Java8 dates etc.
- Protocol-based walker for manipulating Schemas in
schema-tools.walk:walk,prewalkandpostwalk. - Swagger2 generation
- Coercion tools
Latest version
Requires Java 1.8.
Examples
Normal clojure.core functions don't work well with Schemas:
(require '[schema.core :as s])
(s/defschema Address {:street s/Str
(s/optional-key :city) s/Str
(s/required-key :country) {:name s/Str}})
;; where's my city?
(select-keys Address [:street :city])
; {:street java.lang.String}
; this should not return the original Schema name...
(s/schema-name (select-keys Address [:street :city]))
; AddressWith schema-tools:
(require '[schema-tools.core :as st])
(st/select-keys Address [:street :city])
; {:street java.lang.String, #schema.core.OptionalKey{:k :city} java.lang.String}
(s/schema-name (st/select-keys Address [:street :city]))
; nilCoercion
If a given value can't be coerced to match a schema, ex-info is thrown (like schema.core/validate):
(require '[schema-tools.coerce :as stc])
(def matcher (constantly nil))
(def coercer (stc/coercer String matcher))
(coercer 123)
; clojure.lang.ExceptionInfo: Could not coerce value to schema: (not (instance? java.lang.String 123))
; error: (not (instance? java.lang.String 123))
; schema: java.lang.String
; type: :schema-tools.coerce/error
; value: 123
(coercer "123")
; "123"
; same behavior with coerce (creates coercer on each invocation, slower)
(stc/coerce 123 String matcher)
(stc/coerce "123" String matcher)Coercion error :type can be overridden in both cases with an extra argument.
(stc/coerce 123 String matcher :domain/horror)
; clojure.lang.ExceptionInfo: Could not coerce value to schema: (not (instance? java.lang.String 123))
; error: (not (instance? java.lang.String 123))
; schema: java.lang.String
; type: :domain/horror
; value: 123Select Schema
Filtering out illegal schema keys (using coercion):
(st/select-schema {:street "Keskustori 8"
:city "Tampere"
:description "Metosin HQ" ; disallowed-key
:country {:weather "-18" ; disallowed-key
:name "Finland"}}
Address)
; {:city "Tampere", :street "Keskustori 8", :country {:name "Finland"}}Filtering out illegal schema map keys using coercion with additional Json-coercion - in a single sweep:
(s/defschema Beer {:beer (s/enum :ipa :apa)})
(def ipa {:beer "ipa" :taste "good"})
(st/select-schema ipa Beer)
; clojure.lang.ExceptionInfo: Could not coerce value to schema: {:beer (not (#{:ipa :apa} "ipa"))}
; data: {:type :schema.core/error,
; :schema {:beer {:vs #{:ipa :apa}}},
; :value {:beer "ipa", :taste "good"},
; :error {:beer (not (#{:ipa :apa} "ipa"))}}
(require '[schema.coerce :as sc])
(st/select-schema ipa Beer sc/json-coercion-matcher)
; {:beer :ipa}Usage
See the tests.
License
Copyright © 2014-2019 Metosin Oy
Distributed under the Eclipse Public License 2.0.