From 702e7b8972b0ce50314e6d755ad1b08f0bf33848 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Markus=20Penttil=C3=A4?= <markus.penttila@cloudpermit.com>
Date: Wed, 9 Oct 2024 22:14:15 -0400
Subject: [PATCH] Add OpenAPI :requestBody for :form request schema

OpenAPI Specification 3 requires defining form parameters, i.e. classic
application/x-www-form-urlencoded type body as a :requestBody. They are
not supported as regular parameters like in OAS 2.
---
 modules/reitit-openapi/src/reitit/openapi.clj | 13 +++++++++++--
 test/cljc/reitit/openapi_test.clj             | 14 ++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/modules/reitit-openapi/src/reitit/openapi.clj b/modules/reitit-openapi/src/reitit/openapi.clj
index df7c01a4..979620eb 100644
--- a/modules/reitit-openapi/src/reitit/openapi.clj
+++ b/modules/reitit-openapi/src/reitit/openapi.clj
@@ -76,10 +76,12 @@
 (defn- openapi-path [path opts]
   (-> path (trie/normalize opts) (str/replace #"\{\*" "{")))
 
+(def ^:private form-content-type "application/x-www-form-urlencoded")
+
 (defn -get-apidocs-openapi
   [coercion {:keys [request muuntaja parameters responses openapi/request-content-types openapi/response-content-types]} definitions]
-  (let [{:keys [body multipart]} parameters
-        parameters (dissoc parameters :request :body :multipart)
+  (let [{:keys [body form multipart]} parameters
+        parameters (dissoc parameters :request :body :form :multipart)
         ->content (fn [data schema]
                     (merge
                      {:schema schema}
@@ -122,6 +124,13 @@
                                               [content-type {:schema schema}])))
                                      request-content-types)}})
 
+     (when form
+       ;; :form is similar to any other body, but the content type must be application/x-www-form-urlencoded
+       {:requestBody {:content {form-content-type {:schema (->schema-object form
+                                                                            {:in :requestBody
+                                                                             :type :schema
+                                                                             :content-type form-content-type})}}}})
+
      (when request
        ;; :request allows different :requestBody per content-type
        {:requestBody
diff --git a/test/cljc/reitit/openapi_test.clj b/test/cljc/reitit/openapi_test.clj
index 51247337..1b61f428 100644
--- a/test/cljc/reitit/openapi_test.clj
+++ b/test/cljc/reitit/openapi_test.clj
@@ -739,6 +739,13 @@
                             :handler (fn [req]
                                        {:status 200
                                         :body (-> req :parameters :request)})}}]
+                   ["/form-params"
+                    {:post {:description "ring :form-params coercion with :parameters :form syntax"
+                            :coercion coercion
+                            :parameters {:form (->schema :b)}
+                            :handler (fn [req]
+                                       {:status 200
+                                        :body (-> req :parameters :request)})}}]
                    ["/openapi.json"
                     {:get {:handler (openapi/create-openapi-handler)
                            :openapi {:info {:title "" :version "0.0.1"}}
@@ -801,6 +808,13 @@
                    (-> spec
                        (get-in [:paths "/legacy" :post :responses 200 :content])
                        keys)))))
+        (testing ":parameters :form syntax"
+          (testing "body parameter"
+            (is (= ["application/x-www-form-urlencoded"]
+                   (-> spec
+                       (get-in [:paths "/form-params" :post :requestBody :content])
+                       keys))
+                "form parameter schema is put under :requestBody with correct content type")))
         (testing "spec is valid"
           (is (nil? (validate spec))))))))