From 05a5d13a79283c01566ea8d6a847a50429972ad6 Mon Sep 17 00:00:00 2001
From: Noah Bogart <noah.bogart@hey.com>
Date: Thu, 30 Jun 2022 16:57:20 -0400
Subject: [PATCH] Set additionalProperties if map is closed

---
 src/malli/json_schema.cljc       | 7 +++++--
 test/malli/json_schema_test.cljc | 7 +++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/malli/json_schema.cljc b/src/malli/json_schema.cljc
index 5952689be..131bf976c 100644
--- a/src/malli/json_schema.cljc
+++ b/src/malli/json_schema.cljc
@@ -80,11 +80,14 @@
 (defmethod accept :orn [_ _ children _] {:anyOf (map last children)})
 
 (defmethod accept ::m/val [_ _ children _] (first children))
-(defmethod accept :map [_ _ children _]
+(defmethod accept :map [_ schema children _]
   (let [required (->> children (filter (m/-comp not :optional second)) (mapv first))
+        additional-properties (:closed (m/properties schema))
         object {:type "object"
                 :properties (apply array-map (mapcat (fn [[k _ s]] [k s]) children))}]
-    (if (empty? required) object (assoc object :required required))))
+    (cond-> object
+      (seq required) (assoc :required required)
+      additional-properties (assoc :additionalProperties false))))
 
 (defmethod accept :multi [_ _ children _] {:oneOf (mapv last children)})
 
diff --git a/test/malli/json_schema_test.cljc b/test/malli/json_schema_test.cljc
index 28896d4b0..380838b6c 100644
--- a/test/malli/json_schema_test.cljc
+++ b/test/malli/json_schema_test.cljc
@@ -252,3 +252,10 @@
 
 (deftest function-schema-test
   (is (= {} (json-schema/transform [:=> [:cat int? int?] int?]))))
+
+(deftest additional-properties-test
+  (is (= {:type "object"
+          :properties {:name {:type "string"}}
+          :required [:name]
+          :additionalProperties false}
+         (json-schema/transform [:map {:closed true} [:name :string]]))))