From 224aa5b89af00f1fa44b18c9d46c15057ed7d7a5 Mon Sep 17 00:00:00 2001
From: Andrey Antukh <niwi@niwi.nz>
Date: Tue, 28 Dec 2021 23:20:00 +0100
Subject: [PATCH] :bug: Properly handle errors on body parsing middleware.

---
 backend/src/app/http/errors.clj     |  2 +-
 backend/src/app/http/middleware.clj | 52 +++++++++++++----------------
 2 files changed, 24 insertions(+), 30 deletions(-)

diff --git a/backend/src/app/http/errors.clj b/backend/src/app/http/errors.clj
index 91b25beb1d..e4ff27bcfd 100644
--- a/backend/src/app/http/errors.clj
+++ b/backend/src/app/http/errors.clj
@@ -54,7 +54,7 @@
   {:status 400 :body (ex-data err)})
 
 (defmethod handle-exception :validation
-  [err req]
+  [err _]
   (let [edata (ex-data err)]
     {:status 400
      :body   (dissoc edata ::s/problems)}))
diff --git a/backend/src/app/http/middleware.clj b/backend/src/app/http/middleware.clj
index 394240d890..a8cf674458 100644
--- a/backend/src/app/http/middleware.clj
+++ b/backend/src/app/http/middleware.clj
@@ -34,38 +34,32 @@
               (t/read! reader)))
 
           (parse-json [body]
-            (json/read body))
-
-          (parse [type body]
-            (try
-              (case type
-                :json (parse-json body)
-                :transit (parse-transit body))
-              (catch Exception e
-                (let [data {:type :parse
-                            :hint "unable to parse request body"
-                            :message (ex-message e)}]
-                  {:status 400
-                   :headers {"content-type" "application/transit+json"}
-                   :body (t/encode-str data {:type :json-verbose})}))))]
-
+            (json/read body))]
     (fn [{:keys [headers body] :as request}]
-      (let [ctype (get headers "content-type")]
-        (handler
-         (case ctype
-           "application/transit+json"
-           (let [params (parse :transit body)]
-             (-> request
-                 (assoc :body-params params)
-                 (update :params merge params)))
+      (try
+        (let [ctype (get headers "content-type")]
+          (handler (case ctype
+                     "application/transit+json"
+                     (let [params (parse-transit body)]
+                       (-> request
+                           (assoc :body-params params)
+                           (update :params merge params)))
 
-           "application/json"
-           (let [params (parse :json body)]
-             (-> request
-                 (assoc :body-params params)
-                 (update :params merge params)))
+                     "application/json"
+                     (let [params (parse-json body)]
+                       (-> request
+                           (assoc :body-params params)
+                           (update :params merge params)))
 
-           request))))))
+                     request)))
+        (catch Exception e
+          (let [data {:type :validation
+                      :code :unable-to-parse-request-body
+                      :hint "malformed params"}]
+            (l/error :hint (ex-message e) :cause e)
+            {:status 400
+             :headers {"content-type" "application/transit+json"}
+             :body (t/encode-str data {:type :json-verbose})}))))))
 
 (def parse-request-body
   {:name ::parse-request-body