Schema-like lets

CHANGELOG.md

@@ -1,3 +1,19 @@
+## UNRELEASED
+
+Support `:-` in the `:query`, `:body` and `:headers`, e.g. the following are equivalent:
+
+```clj
+(POST "/user" []
+  :return User
+  :body [user User]
+  (ok user))
+
+(POST "/user" []
+  :return User
+  :body [user :- User]
+  (ok user))
+```
+
 ## 2.0.0-alpha15
 
 * updated deps:

src/compojure/api/meta.clj

@@ -59,6 +59,19 @@
   {200 {:schema schema
         :description (or (js/json-schema-meta schema) "")}})
 
+(defn value-and-schema [[value schema ?schema :as binding]]
+  (cond
+    ;; [body :- {:a s/Int}]
+    (and ?schema (= :- schema))
+    [value ?schema]
+
+    ;; [body {:a s/Int}]
+    (not ?schema)
+    [value schema]
+
+    :else
+    (throw (ex-info (str "bad let-binding syntax: " binding) {}))))
+
 ;;
 ;; Extension point
 ;;
@@ -305,12 +318,17 @@
     (help/code
       "(POST \"/echo\" []"
       "  :body [body User]"
+      "  (ok body))"
+      ""
+      "(POST \"/echo\" []"
+      "  :body [body :- User]"
       "  (ok body))")))
 
-(defmethod restructure-param :body [_ [value schema] acc]
-  (-> acc
-      (update-in [:lets] into [value (src-coerce! schema :body-params :body false)])
-      (assoc-in [:info :public :parameters :body] schema)))
+(defmethod restructure-param :body [_ binding acc]
+  (let [[value schema] (value-and-schema binding)]
+    (-> acc
+        (update-in [:lets] into [value (src-coerce! schema :body-params :body false)])
+        (assoc-in [:info :public :parameters :body] schema))))
 
 ;;
 ;; query
@@ -323,12 +341,17 @@
     (help/code
       "(GET \"/search\" []"
       "  :query [params {:q s/Str, :max s/Int}]"
+      "  (ok params))"
+      ""
+      "(GET \"/search\" []"
+      "  :query [params :- {:q s/Str, :max s/Int}]"
       "  (ok params))")))
 
-(defmethod restructure-param :query [_ [value schema] acc]
-  (-> acc
-      (update-in [:lets] into [value (src-coerce! schema :query-params :string)])
-      (assoc-in [:info :public :parameters :query] schema)))
+(defmethod restructure-param :query [_ binding acc]
+  (let [[value schema] (value-and-schema binding)]
+    (-> acc
+        (update-in [:lets] into [value (src-coerce! schema :query-params :string)])
+        (assoc-in [:info :public :parameters :query] schema))))
 
 ;;
 ;; headers
@@ -341,12 +364,17 @@
     (help/code
       "(GET \"/headers\" []"
       "  :headers [headers HeaderSchema]"
+      "  (ok headers))"
+      ""
+      "(GET \"/headers\" []"
+      "  :headers [headers :- HeaderSchema]"
       "  (ok headers))")))
 
-(defmethod restructure-param :headers [_ [value schema] acc]
-  (-> acc
-      (update-in [:lets] into [value (src-coerce! schema :headers :string)])
-      (assoc-in [:info :public :parameters :header] schema)))
+(defmethod restructure-param :headers [_ binding acc]
+  (let [[value schema] (value-and-schema binding)]
+    (-> acc
+        (update-in [:lets] into [value (src-coerce! schema :headers :string)])
+        (assoc-in [:info :public :parameters :header] schema))))
 
 ;;
 ;; body-params

test/compojure/api/integration_test.clj

@@ -202,6 +202,10 @@
                   :return User
                   :query [user User]
                   (ok user))
+                (GET "/user2" []
+                  :return User
+                  :query [user :- User]
+                  (ok user))
                 (GET "/invalid-user" []
                   :return User
                   (ok invalid-user))
@@ -211,6 +215,10 @@
                   :return User
                   :body [user User]
                   (ok user))
+                (POST "/user2" []
+                  :return User
+                  :body [user User]
+                  (ok user))
                 (POST "/user_list" []
                   :return [User]
                   :body [users [User]]
@@ -223,6 +231,10 @@
                   :return User
                   :headers [user UserHeaders]
                   (ok (select-keys user [:id :name])))
+                (POST "/user_headers2" []
+                  :return User
+                  :headers [user :- UserHeaders]
+                  (ok (select-keys user [:id :name])))
                 (POST "/user_legacy" {user :body-params}
                   :return User
                   (ok user))))]
@@ -237,11 +249,21 @@
         status => 200
         body => pertti))
 
+    (fact "GET with smart destructuring & :-"
+      (let [[status body] (get* app "/models/user2" pertti)]
+        status => 200
+        body => pertti))
+
     (fact "POST with smart destructuring"
       (let [[status body] (post* app "/models/user" (json-string pertti))]
         status => 200
         body => pertti))
 
+    (fact "POST with smart destructuring & :-"
+      (let [[status body] (post* app "/models/user2" (json-string pertti))]
+        status => 200
+        body => pertti))
+
     (fact "POST with smart destructuring - lists"
       (let [[status body] (post* app "/models/user_list" (json-string [pertti]))]
         status => 200
@@ -262,6 +284,11 @@
         status => 200
         body => pertti))
 
+    (fact "POST with smart destructuring - headers & :-"
+      (let [[status body] (headers-post* app "/models/user_headers2" pertti)]
+        status => 200
+        body => pertti))
+
     (fact "Validation of returned data"
       (let [[status] (get* app "/models/invalid-user")]
         status => 500))