Add malli.util/merge call to route data merge

Fixes #422

modules/reitit-core/src/reitit/impl.cljc

@@ -4,7 +4,9 @@
             [clojure.set :as set]
             [meta-merge.core :as mm]
             [reitit.trie :as trie]
-            [reitit.exception :as ex])
+            [reitit.exception :as ex]
+            ;; FIXME: Can't be used directly, should be option enabled by malli coercion
+            malli.util)
   #?(:clj
      (:import (java.util HashMap Map)
               (java.net URLEncoder URLDecoder))))
@@ -64,7 +66,11 @@
   (reduce
     (fn [acc [k v]]
       (try
-        (mm/meta-merge acc {k v})
+        (case k
+          ;; TODO: Make this enabled from malli coercion
+          ;; TODO: Schema & spec
+          :parameters (assoc acc :parameters (merge-with malli.util/merge (:parameters acc) v))
+          (mm/meta-merge acc {k v}))
         (catch #?(:clj Exception, :cljs js/Error) e
           (ex/fail! ::merge-data {:path p, :left acc, :right {k v}, :exception e}))))
     {} x))

test/cljc/reitit/impl_test.cljc

@@ -169,3 +169,34 @@
           :path-parts ["https://google.com"]
           :path-params #{}}
          (impl/parse "https://google.com" nil))))
+
+(deftest merge-data-test
+  (is (= {:view 'b
+          :controllers [1 2]}
+         (impl/merge-data "/"
+                          [[:view 'a]
+                           [:controllers [1]]
+                           [:view 'b]
+                           [:controllers [2]]])))
+
+  (is (= {:view 'b
+          :controllers [2]}
+         (impl/merge-data "/"
+                          [[:view 'a]
+                           [:controllers [1]]
+                           [:view 'b]
+                           [:controllers ^:replace [2]]])))
+
+  (is (= [:map
+          [:a 'string?]
+          [:b 'int?]]
+         (-> (impl/merge-data "/"
+                              [[:parameters {:path [:map [:a 'string?]]}]
+                               [:parameters {:path [:map [:b 'int?]]}]])
+             :parameters
+             :path
+             ;; Merge returns schmea object, convert back to form for comparison
+             malli.core/form)))
+
+  ;; TODO: Also test and support Schema and spec merging
+  )