Malli coercion incorrectly rejects [:or [:map ...] [:map ...]]

[crclark]

If I specify that a POST or PUT body should conform to either of two :map schemata, the malli coercion middleware incorrectly rejects both.

Working from the ring-malli-swagger example, with this patch:

--- a/examples/ring-malli-swagger/src/example/server.clj
+++ b/examples/ring-malli-swagger/src/example/server.clj
@@ -16,8 +16,13 @@
             [ring.adapter.jetty :as jetty]
             [muuntaja.core :as m]
             [clojure.java.io :as io]
+            [malli.core :as malli]
             [malli.util :as mu]))
 
+(def or-maps-schema
+  (malli/schema
+   [:or [:map [:x int?]] [:map [:y int?]]]))
+
 (def app
   (ring/ring-handler
     (ring/router
@@ -66,7 +71,15 @@
                  :responses {200 {:body [:map [:total int?]]}}
                  :handler (fn [{{{:keys [x y]} :body} :parameters}]
                             {:status 200
-                             :body {:total (+ x y)}})}}]]]
+                             :body {:total (+ x y)}})}}]]
+
+       ["/ormaps"
+        {:post {:summary "accepts either of two map schemas"
+                :parameters {:body or-maps-schema}
+                :responses {200 {:body [:map [:msg string?]]}}
+                :handler (fn [{{{:keys [x y]} :body} :parameters}]
+                           {:status 200
+                            :body {:msg (if x "you sent x" "you sent y")}})}}]]
 
       {;;:reitit.middleware/transform dev/print-request-diffs ;; pretty diffs
        ;;:validate spec/validate ;; enable spec validation for route data
-- 

In the repl, I can see that both maps are accepted by malli.core/validate, as I expect:

example.server=> (require '[malli.core :as m])
nil
example.server=> (m/validate or-maps-schema {:x 1})
true
example.server=> (m/validate or-maps-schema {:y 1})
true
example.server=> (malli/validate or-maps-schema {:z 1})
false

However, if I POST, I get a 400 response:

➜ http POST :3000/ormaps x:=1
HTTP/1.1 400 Bad Request
Content-Length: 529
Content-Type: application/json;charset=utf-8
Date: Fri, 22 May 2020 19:58:21 GMT
Server: Jetty(9.4.12.v20180830)

{
    "coercion": "malli",
    "errors": [
        {
            "in": [
                "x"
            ],
            "message": "missing required key",
            "path": [
                1,
                2,
                0
            ],
            "schema": "[:map {:closed true} [:x int?]]",
            "type": "malli.core/missing-key",
            "value": null
        },
        {
            "in": [
                "y"
            ],
            "message": "missing required key",
            "path": [
                2,
                2,
                0
            ],
            "schema": "[:map {:closed true} [:y int?]]",
            "type": "malli.core/missing-key",
            "value": null
        }
    ],
    "humanized": {
        "x": [
            "missing required key"
        ],
        "y": [
            "missing required key"
        ]
    },
    "in": [
        "request",
        "body-params"
    ],
    "schema": "[:or [:map {:closed true} [:x int?]] [:map {:closed true} [:y int?]]]",
    "value": {
        "x": 1
    }
}

[ikitommi]

Minimal repro:

(m/decode
  [:or
   [:map [:x int?]]
   [:map [:y keyword?]]]
  {:x 1}
  mt/strip-extra-keys-transformer)
; => {}

I think we need to check validity on transformation :leave for each element and pick the first valid one.

[ikitommi]

should be fixed in [metosin/malli "0.0.1-20200525.162645-15"].